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New submissions for Wed, 8 Apr 20
- [1] arXiv:2004.02883 [pdf, other]
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Title: A systematic aging method I: HII regions D118 and D119 in NGC 300Comments: Submitted to MNRAS, comments welcome, 16 pages, 12 figures, 3 TablesSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)
Accurately determining the age of H\,{ii} regions and the stars they host is as important as it is challenging. Historically the most popular method has been isochrone fitting to Hertzsprung-Russell Diagrams or Colour-Magnitude Diagrams. Here we introduce a different method for age determination using BPASS and hoki. We infer the most likely ages of the regions D118 and D119 NGC 300 to be log(age/years)=6.86$^{0.05}_{0.16}$ and we also deduce stellar mass and number counts by comparison with the BPASS models. We compare how our binary and single star models perform and find that the latter are unable to predict 20 per cent ($\pm$ 10 per cent) of our sample. We also discuss how results obtained from isochrone fitting would differ. We conclude that ages could be underestimated by ~0.2 dex and that the limitations of the isochrone method is not solely due to the lack of binary stars. We propose that the method presented here is more reliable and more widely applicable since it can be used on smaller samples. Alongside this study, we release new hoki features to allow easy implementation of this method.
- [2] arXiv:2004.02884 [pdf, other]
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Title: A Hard X-ray Test of HCN Enhancements as a Tracer of Embedded Black Hole GrowthAuthors: G. C. Privon, C. Ricci, S. Aalto, S. Viti, L. Armus, T. Díaz-Santos, E. González-Alfonso, K. Iwasawa, D. L. Jeff, E. Treister, F. Bauer, A. S. Evans, P. Garg, R. Herrero-Illana, J. M. Mazzarella, K. Larson, L. Blecha, L. Barcos-Muñoz, V. Charmandaris, S. Stierwalt, M. A. Pérez-TorresComments: 14 pages, 4 figures. accepted for publication in The Astrophysical JournalSubjects: Astrophysics of Galaxies (astro-ph.GA); High Energy Astrophysical Phenomena (astro-ph.HE)
Enhanced emission from the dense gas tracer HCN (relative to HCO$^+ $) has been proposed as a signature of active galactic nuclei (AGN). In a previous single-dish millimeter line survey we identified galaxies with HCN/HCO$ ^+ $ (1-0) intensity ratios consistent with those of many AGN but whose mid-infrared spectral diagnostics are consistent with little to no ( $\lesssim15\% $) contribution of an AGN to the bolometric luminosity. To search for putative heavily obscured AGN, we present and analyze \nustar hard X-ray (3-79 keV) observations of four such galaxies from the Great Observatories All-sky LIRG Survey. We find no X-ray evidence for AGN in three of the systems and place strong upper limits on the energetic contribution of any heavily obscured ($N _{\rm H}>10^{24}$ cm$^{-2}$) AGN to their bolometric luminosity. The X-ray flux upper limits are presently an order of magnitude below what XDR-driven chemistry model predict are necessary to drive HCN enhancements. In a fourth system we find a hard X-ray excess consistent with the presence of an AGN, but contributing only $\sim3\%$ of the bolometric luminosity. It is also unclear if the AGN is spatially associated with the HCN enhancement. We further explore the relationship between HCN/HCO$^+$ (for several $\mathrm{J}_\mathrm{upper}$ levels) and $L_\mathrm{AGN}/L_\mathrm{IR}$ for a larger sample of systems in the literature. We find no evidence for correlations between the line ratios and the AGN fraction derived from X-rays, indicating that HCN/HCO$^+$ intensity ratios are not driven by the energetic dominance of AGN, nor are they reliable indicators of whether SMBH accretion is ongoing.
- [3] arXiv:2004.02891 [pdf, other]
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Title: From Nuclear to Circumgalactic: Zooming in on AGN-Driven Outflows at z~2.2 with SINFONIAuthors: Rebecca L. Davies, N. M. Förster Schreiber, D. Lutz, R. Genzel, S. Belli, T.T. Shimizu, A. Contursi, R.I. Davies, R. Herrera-Camus, M.M. Lee, T. Naab, S.H. Price, A. Renzini, A. Schruba, A. Sternberg, L.J. Tacconi, H. Übler, E. Wisnioski, S. WuytsComments: Accepted for publication in ApJ. Main text 23 pages, 15 figures and 4 tables, plus Appendix (3 pages, 3 figures, 1 table)Subjects: Astrophysics of Galaxies (astro-ph.GA)
We use deep adaptive optics assisted integral field spectroscopy from SINFONI on the VLT to study the spatially resolved properties of ionized gas outflows driven by active galactic nuclei (AGN) in three galaxies at z~2.2 -- K20-ID5, COS4-11337 and J0901+1814. These systems probe AGN feedback from nuclear to circumgalactic scales, and provide unique insights into the different mechanisms by which AGN-driven outflows interact with their host galaxies. K20-ID5 and COS4-11337 are compact star forming galaxies with powerful $\sim$1500 km s$^{-1}$ AGN-driven outflows that dominate their nuclear H$\alpha$ emission. The outflows do not appear to have any impact on the instantaneous star formation activity of the host galaxies, but they carry a significant amount of kinetic energy which could heat the halo gas and potentially lead to a reduction in the rate of cold gas accretion onto the galaxies. The outflow from COS4-11337 is propagating directly towards its companion galaxy COS4-11363, at a projected separation of 5.4 kpc. COS4-11363 shows signs of shock excitation and recent truncation of star formation activity, which could plausibly have been induced by the outflow from COS4-11337. J0901+1814 is gravitationally lensed, giving us a unique view of a compact (R = 470 $\pm$ 70 pc), relatively low velocity ($\sim$650 km s$^{-1}$) AGN-driven outflow. J0901+1814 has a similar AGN luminosity to COS4-11337, suggesting that the difference in outflow properties is not related to the current AGN luminosity, and may instead reflect a difference in the evolutionary stage of the outflow and/or the coupling efficiency between the AGN ionizing radiation field and the gas in the nuclear regions.
- [4] arXiv:2004.02894 [pdf, other]
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Title: The Bardeen-Petterson effect in accreting supermassive black-hole binaries: a systematic approachComments: 17 pages, 14 figuresSubjects: Astrophysics of Galaxies (astro-ph.GA); High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc)
Disc-driven migration is a key evolutionary stage of supermassive black-hole binaries hosted in gas-rich galaxies. Besides promoting the inspiral, viscous interactions tend to align the spin of the black hole with the orbital angular momentum of the disc. We present a critical and systematic investigation of this problem, also known as the Bardeen-Petterson effect. We design a new iterative scheme to solve the non-linear dynamics of warped accretion discs under the influence of both relativistic frame-dragging and binary companion. We characterize the impact of the disc "critical obliquity", which marks regions of the parameter space where viable evolutionary paths cease to exist. We find that black-hole spins reach either complete alignment or a critical configuration. Our findings are important to predict the spin configurations with which supermassive black-hole binaries enter their gravitational-wave driven regime and become detectable by LISA.
- [5] arXiv:2004.02895 [pdf, other]
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Title: An Upper Limit on the Initial Temperature of the Radiation-Dominated UniverseComments: 5 pages, 2 figures, submitted to PRL, comments welcomeSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
Gravitational waves (GWs) are produced by colliding particles through the gravitational analogue of electromagnetic bremsstrahlung. We calculate the contribution of free-free emission in the radiation-dominated Universe to the stochastic GW background. We find that the energy density of the resulting GW radiation is heavily dependent on the number of elementary particles, $N_{\mathrm{tot}}$, and the maximum initial temperature, $T_{\mathrm{max}}$. We rule out $N_{\mathrm{tot}}\gtrsim N_{\mathrm{SM}}$ for $T_{\mathrm{max}}\sim T_{\mathrm{Planck}}\approx10^{19}$ GeV and $N_{\mathrm{tot}}\gtrsim10^{13}\times N_{\mathrm{SM}}$ for $T_{\mathrm{max}}\sim10^{16}$ GeV, where $N_{\mathrm{SM}}$ is the number of particles in the Standard Model. In the case of inflation, existing cosmological data constrain $T_{\mathrm{max}}\lesssim10^{16}$ GeV. However, alternative models to inflation such as bouncing cosmologies allow for $T_{\mathrm{max}}$ near $T_{\mathrm{Planck}}$. At the energy scales we are considering, the extra number of particles arise naturally in models of extra dimensions.
- [6] arXiv:2004.02897 [pdf, other]
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Title: Effects of Different Cosmic Ray Transport Models on Galaxy FormationAuthors: Philip F. Hopkins (Caltech), T. K. Chan (ICC Durham), Jonathan Squire (Otago), Eliot Quataert (Berkeley), Suoqing Ji (Caltech), Dusan Keres (UCSD), Claude-Andre Faucher-Giguere (Northwestern)Comments: 6 pages, 2 figures. Submitted to MNRAS. Comments welcomeSubjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Astrophysical Phenomena (astro-ph.HE); Plasma Physics (physics.plasm-ph)
Cosmic rays (CRs) with ~GeV energies can contribute significantly to the energy and pressure budget in the interstellar, circumgalactic, and intergalactic medium (ISM, CGM, IGM). Recent cosmological simulations have begun to explore these effects, but almost all studies have been restricted to simplified models with constant CR diffusivity and/or streaming speeds. Physical models of CR propagation/scattering via extrinsic turbulence and self-excited waves predict transport coefficients which are complicated functions of local plasma properties. In a companion paper, we consider a wide range of observational constraints to identify proposed physically-motivated cosmic-ray propagation scalings which satisfy both detailed Milky Way (MW) and extra-galactic $\gamma$-ray constraints. Here, we compare the effects of these models relative to simpler 'diffusion+streaming' models on galaxy and CGM properties at dwarf through MW mass scales. The physical models predict large local variations in CR diffusivity, with median diffusivity increasing with galacto-centric radii and decreasing with galaxy mass and redshift. These effects lead to a more rapid dropoff of CR energy density in the CGM (compared to simpler models), in turn producing weaker effects of CRs on galaxy star formation rates (SFRs), CGM absorption profiles and galactic outflows. The predictions of the more physical CR models tend to lie 'in between' models which ignore CRs entirely and models which treat CRs with constant diffusivity.
- [7] arXiv:2004.02898 [pdf, other]
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Title: Self-gravitating Filament Formation from Shocked Flows: Velocity Gradients across FilamentsComments: 11 pages, 7 figures, accepted for publication in MNRASSubjects: Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)
In typical environments of star-forming clouds, converging supersonic turbulence generates shock-compressed regions, and can create strongly-magnetized sheet-like layers. Numerical MHD simulations show that within these post-shock layers, dense filaments and embedded self-gravitating cores form via gathering material along the magnetic field lines. As a result of the preferred-direction mass collection, a velocity gradient perpendicular to the filament major axis is a common feature seen in simulations. We show that this prediction is in good agreement with recent observations from the CARMA Large Area Star Formation Survey (CLASSy), from which we identified several filaments with prominent velocity gradients perpendicular to their major axes. Highlighting a filament from the northwest part of Serpens South, we provide both qualitative and quantitative comparisons between simulation results and observational data. In particular, we show that the dimensionless ratio $C_v \equiv {\Delta v_h}^2/(GM/L)$, where $\Delta v_h$ is half of the observed perpendicular velocity difference across a filament, and $M/L$ is the filament's mass per unit length, can distinguish between filaments formed purely due to turbulent compression and those formed due to gravity-induced accretion. We conclude that the perpendicular velocity gradient observed in the Serpens South northwest filament can be caused by gravity-induced anisotropic accretion of material from a flattened layer. Using synthetic observations of our simulated filaments, we also propose that a density-selection effect may explain observed subfilaments (one filament breaking into two components in velocity space) as reported in Dhabal et al. (2018).
- [8] arXiv:2004.02901 [pdf, other]
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Title: PSR J1012+5307: a millisecond pulsar with an extremely low-mass white dwarf companionAuthors: D. Mata Sánchez (1), A. G. Istrate (2), M. H. van Kerkwijk (3), R. P. Breton (1), D. L. Kaplan (4) ((1) Jodrell Bank Centre for Astrophysics, Department of Physics and Astronomy, The University of Manchester, M13 9PL, UK, (2) Department of Astrophysics/IMAPP, Radboud University, PO Box 9010, NL-6500 GL Nijmegen, The Netherlands, (3) Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4, Canada, (4) Center for Gravitation, Cosmology and Astrophysics, Department of Physics, University of Wisconsin-Milwaukee, PO Box 413, Milwaukee, WI 53201, USA)Comments: 13 pages, 7 figures. Accepted for publication in MNRASSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR)
Binaries harbouring millisecond pulsars enable a unique path to determine neutron star masses: radio pulsations reveal the motion of the neutron star, while that of the companion can be characterised through studies in the optical range. PSR J1012+5307 is a millisecond pulsar in a 14.5-h orbit with a helium-core white dwarf companion. In this work we present the analysis of an optical spectroscopic campaign, where the companion star absorption features reveal one of the lightest known white dwarfs. We determine a white dwarf radial velocity semi-amplitude of K_2 = 218.9 +- 2.2 km/s, which combined with that of the pulsar derived from the precise radio timing, yields a mass ratio of q=10.44+- 0.11. We also attempt to infer the white dwarf mass from observational constraints using new binary evolution models for extremely low-mass white dwarfs, but find that they cannot reproduce all observed parameters simultaneously. In particular, we cannot reconcile the radius predicted from binary evolution with the measurement from the photometric analysis (R_WD=0.047+-0.003 Rsun). Our limited understanding of extremely low-mass white dwarf evolution, which results from binary interaction, therefore comes as the main factor limiting the precision with which we can measure the mass of the white dwarf in this system. Our conservative white dwarf mass estimate of M_WD = 0.165 +- 0.015 Msun, along with the mass ratio enables us to infer a pulsar mass of M_NS = 1.72 +- 0.16 Msun. This value is clearly above the canonical 1.4 Msun, therefore adding PSR J1012+5307 to the growing list of massive millisecond pulsars.
- [9] arXiv:2004.02904 [pdf, ps, other]
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Title: Relation of X-ray activity and rotation in M dwarfs and predicted time-evolution of the X-ray luminosityComments: Accepted for publication by A&ASubjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP)
We present a sample of 14 M dwarf stars observed with XMM-Newton and Chandra, for which we also computed rotational periods from Kepler Two-Wheel (K2) Mission light curves. We compiled X-ray and rotation data from the literature and homogenized all data sets to provide the largest uniform sample of M dwarfs (302 stars) for X-ray activity and rotation studies to date. We then fit the relation between $L_{\rm x} - P_{\rm rot}$ using three different mass bins to separate partially and fully convective stars. We found a steeper slope in the unsaturated regime for fully convective stars and a nonconstant $L_{\rm x}$ level in the saturated regime for all masses. In the $L_{\rm x}/L_{\rm bol}-R_{\rm O}$ space we discovered a remarkable double gap that might be related to a discontinuous period evolution. Then we combined the evolution of $P_{\rm rot}$ predicted by angular momentum evolution models with our new results on the empirical $L_{\rm x} - P_{\rm rot}$ relation to provide an estimate for the age decay of X-ray luminosity. We compare predictions of this relationship with the actual X-ray luminosities of M stars with known ages from 100 Myr to a few billion years. We find remarkably good agreement between the predicted $L_{\rm x}$ and the observed values for partially convective stars. However, for fully convective stars at ages of a few billion years, the constructed $L_{\rm x}-$age relation overpredicts the X-ray luminosity because the angular momentum evolution model underpredicts the rotation period of these stars. Finally, we examine the effect of different parameterizations for the Rossby number ($R_{\rm O}$) on the shape of the activity-rotation relation in $L_{\rm x}/L_{\rm bol}-R_{\rm O}$ space, and we find that the slope in the unsaturated regime and the location of the break point of the dual power-law depend sensitively on the choice of $R_{\rm O}$.
- [10] arXiv:2004.02906 [pdf, other]
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Title: New Insight into the stellar mass function of Galactic globular clustersComments: 19 pages, 13 figures, accepted for publication by MNRASSubjects: Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)
We present the results of the analysis of deep photometric data of 32 Galactic globular clusters. We analysed 69 parallel field images observed with the Wide Field Channel of the Advanced Camera for Surveys of the Hubble Space Telescope which complemented the already available photometry from the globular cluster treasury project covering the central regions of these clusters. This unprecedented data set has been used to calculate the relative fraction of stars at different masses (i.e. the present-day mass function) in these clusters by comparing the observed distribution of stars along the cluster main sequence and across the analysed field of view with the prediction of multimass dynamical models. For a subsample of 31 clusters, we were able to obtain also the half-mass radii, mass-to-light ratios and the mass fraction of dark remnants using available radial velocity information. We found that the majority of globular clusters have single power law mass functions $F(m) \propto m^\alpha$ with slopes $\alpha>-1$ in the mass range $0.2<m/\text{M}_{\odot}<0.8$. By exploring the correlations between the structural/dynamical and orbital parameters, we confirm the tight anticorrelation between the mass function slopes and the half-mass relaxation times already reported in previous works, and possible second-order dependence on the cluster metallicity. This might indicate the relative importance of both initial conditions and evolutionary effects on the present-day shape of the mass function.
- [11] arXiv:2004.02910 [pdf, other]
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Title: IceCube Search for Neutrinos Coincident with Compact Binary Mergers from LIGO-Virgo's First Gravitational-Wave Transient CatalogAuthors: M. G. Aartsen, M. Ackermann, J. Adams, J. A. Aguilar, M. Ahlers, M. Ahrens, C. Alispach, K. Andeen, T. Anderson, I. Ansseau, G. Anton, C. Argüelles, J. Auffenberg, S. Axani, H. Bagherpour, X. Bai, A. Balagopal V., A. Barbano, I. Bartos, S. W. Barwick, B. Bastian, V. Baum, S. Baur, R. Bay, J. J. Beatty, K.-H. Becker, J. Becker Tjus, S. BenZvi, D. Berley, E. Bernardini, D. Z. Besson, G. Binder, D. Bindig, E. Blaufuss, S. Blot, C. Bohm, S. Böser, O. Botner, J. Böttcher, E. Bourbeau, J. Bourbeau, F. Bradascio, J. Braun, S. Bron, J. Brostean-Kaiser, A. Burgman, J. Buscher, R. S. Busse, T. Carver, C. Chen, E. Cheung, D. Chirkin, S. Choi, B. A. Clark, K. Clark, L. Classen, A. Coleman, G. H. Collin, J. M. Conrad, P. Coppin, K. R. Corley, P. Correa, S. Countryman, D. F. Cowen, R. Cross, et al. (313 additional authors not shown)Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)
Using the IceCube Neutrino Observatory, we search for high-energy neutrino emission coincident with compact binary mergers observed by the LIGO and Virgo gravitational wave (GW) detectors during their first and second observing runs. We present results from two searches targeting emission coincident with the sky localization of each gravitational wave event within a 1000 second time window centered around the reported merger time. One search uses a model-independent unbinned maximum likelihood analysis, which uses neutrino data from IceCube to search for point-like neutrino sources consistent with the sky localization of GW events. The other uses the Low-Latency Algorithm for Multi-messenger Astrophysics, which incorporates astrophysical priors through a Bayesian framework and includes LIGO-Virgo detector characteristics to determine the association between the GW source and the neutrinos. No significant neutrino coincidence is seen by either search during the first two observing runs of the LIGO-Virgo detectors. We set upper limits on the time-integrated neutrino emission within the 1000 second window for each of the 11 GW events. These limits range from 0.02-0.7 $\mathrm{GeV~cm^{-2}}$. We also set limits on the total isotropic equivalent energy, $E_{\mathrm{iso}}$, emitted in high-energy neutrinos by each GW event. These limits range from 1.7 $\times$ 10$^{51}$ - 1.8 $\times$ 10$^{55}$ erg. We conclude with an outlook for LIGO-Virgo observing run O3, during which both analyses are running in real time.
- [12] arXiv:2004.02916 [pdf, ps, other]
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Title: The Evolution Of The Inner Regions of Protoplanetary DisksAuthors: Ezequiel Manzo-Martínez, Nuria Calvet, Jesús Hernández, Susana Lizano, Ramiro Franco Hernández, Christopher J. Miller, Karina Maucó, César Briceño, Paola D'AlessioComments: Accepted for publication in the Astrophysical JournalSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA)
We present a study of the evolution of the inner few astronomical units of protoplanetary disks around low-mass stars. We consider nearby stellar groups with ages spanning from 1 to 11 Myr, distributed into four age bins. Combining PANSTARSS photometry with spectral types, we derive the reddening consistently for each star, which we use (1) to measure the excess emission above the photosphere with a new indicator of IR excess and (2) to estimate the mass accretion rate ($\dot{M}$) from the equivalent width of the H$\alpha$ line. Using the observed decay of $\dot{M}$ as a constrain to fix the initial conditions and the viscosity parameter of viscous evolutionary models, we use approximate Bayesian modeling to infer the dust properties that produce the observed decrease of the IR excess with age, in the range between 4.5 and $24\,\mu$m. We calculate an extensive grid of irradiated disk models with a two-layered wall to emulate a curved dust inner edge and obtain the vertical structure consistent with the surface density predicted by viscous evolution. We find that the median dust depletion in the disk upper layers is $\epsilon \sim 3 \times 10^{-3}$ at 1.5 Myr, consistent with previous studies, and it decreases to $\epsilon \sim 3 \times 10^{-4}$ by 7.5 Myr. We include photoevaporation in a simple model of the disk evolution and find that a photoevaporative wind mass-loss rate of $\sim 1 -3 \times 10 ^{-9} \, M_{\odot}yr^{-1}$ agrees with the decrease of the disk fraction with age reasonably well. The models show the inward evolution of the H$_2$O and CO snowlines.
- [13] arXiv:2004.02918 [pdf, other]
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Title: Dust clearing by radial drift in evolving protoplanetary disksComments: 18 pages, 18 figures, accepted for publication in A&ASubjects: Earth and Planetary Astrophysics (astro-ph.EP)
Recent surveys have revealed that protoplanetary disks typically have dust masses that appear to be insufficient to account for the high occurrence rate of exoplanet systems. We demonstrate that this observed dust depletion is consistent with the radial drift of pebbles. Using a Monte Carlo method we simulate the evolution of a cluster of protoplanetary disks, using a 1D numerical method to viscously evolve each gas disk together with the radial drift of dust particles that have grown to 100 $\mu$m in size. For a 2 Myr old cluster of stars, we find a slightly sub-linear scaling between the gas disk mass and the gas accretion rate ($M_\mathrm{g}\propto\dot{M}^{0.9}$). However, for the dust mass we find that evolved dust disks have a much weaker scaling with the gas accretion rate, with the precise scaling depending on the age at which the cluster is sampled and the intrinsic age spread of the disks in the cluster. Ultimately, we find that the dust mass present in protoplanetary disk is on the order of 10-100 Earth masses in 1-3 Myr old star-forming regions, a factor of 10 to 100 depleted from the original dust budget. As the dust drains from the outer disk, pebbles pile up in the inner disk and locally increase the dust-to-gas ratio by a factor of up to 4 above the initial value. In these high dust-to-gas ratio regions we find conditions that are favourable for planetesimal formation via the streaming instability and subsequent growth by pebble accretion. We also find the following scaling relations with stellar mass within a 1-2 Myr old cluster: a slightly super-linear scaling between the gas accretion rate and stellar mass ($\dot{M}\propto M_\star^{1.4}$), a slightly super-linear scaling between the gas disk mass and the stellar mass ($M_\mathrm{g}\propto M_\star^{1.4}$) and a super-linear relation between the dust disk mass and stellar mass ($M_\mathrm{d}\propto M_\star^{1.4-4.1}$).
- [14] arXiv:2004.02923 [pdf, other]
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Title: HD 165054: an astrometric calibration field for high-contrast imagers in Baade's WindowAuthors: Meiji M. Nguyen, Robert J. De Rosa, Jason J. Wang, Thomas M. Esposito, Paul Kalas, James R. Graham, Bruce Macintosh, Vanessa P. Bailey, Travis Barman, Joanna Bulger, Jeffrey Chilcote, Tara Cotten, Rene Doyon, Gaspard Duchêne, Michael P. Fitzgerald, Katherine B. Follette, Benjamin L. Gerard, Stephen J. Goodsell, Alexandra Z. Greenbaum, Pascale Hibon, Justin Hom, Li-Wei Hung, Patrick Ingraham, Quinn Konopacky, James E. Larkin, Jérôme Maire, Franck Marchis, Mark S. Marley, Christian Marois, Stanimir Metchev, Maxwell A. Millar-Blanchaer, Eric L. Nielsen, Rebecca Oppenheimer, David Palmer, Jennifer Patience, Marshall Perrin, Lisa Poyneer, Laurent Pueyo, Abhijith Rajan, Julien Rameau, Fredrik T. Rantakyrö, Bin Ren, Jean-Baptiste Ruffio, Dmitry Savransky, Adam C. Schneider, Anand Sivaramakrishnan, et al. (8 additional authors not shown)Comments: 25 pages, 12 figuresSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Earth and Planetary Astrophysics (astro-ph.EP)
We present a study of the HD 165054 astrometric calibration field that has been periodically observed with the Gemini Planet Imager. HD 165054 is a bright star within Baade's Window, a region of the galactic plane with relatively low extinction from interstellar dust. HD 165054 was selected as a calibrator target due to the high number density of stars within this region ($\sim 3$ stars per square arcsecond with $H<22$), necessary because of the small field-of-view of the Gemini Planet Imager. Using nine epochs spanning over five years, we have fit a standard five-parameter astrometric model to the astrometry of seven background stars within close proximity to HD 165054 (angular separation $< 2$ arcsec). We achieved a proper motion precision of $\sim 0.3$ mas/yr, and constrained the parallax of each star to be $\lesssim 1$ mas. Our measured proper motions and parallax limits are consistent with the background stars being a part of the galactic bulge. Using these measurements we find no evidence of any systematic trend of either the plate scale or the north angle offset of GPI between 2014 and 2019. We compared our model describing the motions of the seven background stars to observations of the same field in 2014 and 2018 obtained with Keck/NIRC2, an instrument with an excellent astrometric calibration. We find that predicted position of the background sources is consistent with that measured by NIRC2, within the uncertainties of the calibration of the two instruments. In the future, we will use this field as a standard astrometric calibrator for the upgrade of GPI and potentially for other high-contrast imagers.
- [15] arXiv:2004.02926 [pdf, other]
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Title: Post-inflationary axion isocurvature perturbations facing CMB and large-scale structureAuthors: Martin Feix, Steffen Hagstotz, Andreas Pargner, Robert Reischke, Bjoen Malte Schaefer, Thomas SchwetzComments: 25 pages, 11 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph)
Dark matter comprised of axion-like particles (ALPs) generated by the realignment mechanism in the post-inflationary scenario leads to primordial isocurvature fluctuations. The power spectrum of these fluctuations is flat for small wave numbers, extending to scales accessible with cosmological surveys. We use the latest measurements of Cosmic Microwave Background (CMB) primary anisotropies together with CMB lensing, Baryonic Acoustic Oscillations (BAO) and Sunyaev Zel'dovich (SZ) cluster counts to measure the amplitude and tilt of the isocurvature component. We find preference for a white-noise isocurvature component in the CMB primary anisotropies; this conclusion is, however, weakened by current large-scale structure (LSS) data. Interpreting the result as a conservative upper limit on the isocurvature component, the combined bound on the ALP mass from all probes is $m_{a} \gtrsim 10^{-19}$ eV, with some dependence on how $m_{a}$ evolves with temperature. The expected sensitivity of cosmic shear and galaxy clustering from future LSS experiments and CMB lensing suggests improved bounds of $m_{a} \gtrsim 10^{-18}$-$10^{-13}$ eV, depending on scale cuts used to avoid non-linearities and the ALP mass-temperature dependence.
- [16] arXiv:2004.02927 [pdf, other]
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Title: Revised estimates of CMB $B$-mode polarization induced by patchy reionizationAuthors: Anirban Roy, Girish Kulkarni, P. Daniel Meerburg, Anthony Challinor, Carlo Baccigalupi, Andrea Lapi, Martin G. HaehneltComments: 26 pages, 7 figures, submitted to JCAPSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
The search for primordial gravitational waves through the $B$-mode polarization pattern in the CMB is one of the major goals of current and future CMB experiments. Besides foregrounds, a potential hurdle in this search is the anisotropic secondary $B$-mode polarization generated by the scattering of CMB photons off free electrons produced during patchy cosmological reionization. Robust predictions of these secondary anisotropies are challenging because of uncertainties in the reionization history. In this paper, we revise estimates of the reionization-induced $B$-mode signal by incorporating recent advances in the understanding of reionization through observations of the Lyman-$\alpha$ forest. To derive these $B$-mode estimates, we use high-dynamic-range radiative transfer simulations of reionization that are calibrated to the Ly$\alpha$ data. These simulations are also consistent with a variety of other high-redshift observations. We find that around multipoles $\ell\approx 100$, reionization induces $B$-mode power with $\ell(\ell+1)C_\ell^{BB}/2\pi\approx 4\times 10^{-6}\,\mu$K$^2$. This secondary signal is thus at the level of the primordial signal with the tensor-to-scalar ratio $r<10^{-4}$, and can increase by a factor of $\sim 50$ if reionization is sourced by highly clustered sources residing in haloes with mass of $\sim 10^{11}$ M$_\odot$. Our findings suggest that the contribution of patchy reionization to the search for primordial gravitational waves is unlikely to be a concern for currently planned CMB experiments.
- [17] arXiv:2004.02937 [pdf, other]
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Title: The common origin of the Hubble tension and anomalous cold spots in the CMBComments: 14 pages, 8 figures, submitted to MNRASSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
The standard cosmological paradigm narrates a reassuring story of a universe currently dominated by an enigmatic dark energy component. Disquietingly, its universal explaining power has recently been challenged by, above all, the $\sim4\sigma$ tension in the values of the Hubble constant. A more durable yet less studied other anomaly is the repeated observation of integrated Sachs-Wolfe imprints $\sim5\times$ stronger than expected in the $\Lambda$CDM model from $R_v > 100\,h^{-1}Mpc$ super-structures. Here we show that the inhomogeneous AvERA model of emerging curvature is capable of telling a plausible albeit radically different story that explains both observational anomalies without dark energy. We demonstrate that while stacked imprints of $R_v > 100\,h^{-1}Mpc$ supervoids in cosmic microwave background temperature maps can discriminate between the AvERA and $\Lambda$CDM models, their characteristic differences may remain hidden using alternative void definitions and stacking methodologies. Testing the extremes, we then also show that the CMB Cold Spot can plausibly be explained in the AvERA model as an ISW imprint. We hence conclude that the anomalous imprint of supervoids may well be the canary in the coal mine, and existing observational evidence for dark energy should be re-interpreted to further test alternative models.
- [18] arXiv:2004.02960 [pdf, other]
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Title: Large-scale asymmetry between clockwise and counterclockwise galaxies revisitedAuthors: Lior ShamirComments: AN, acceptedSubjects: Astrophysics of Galaxies (astro-ph.GA); Instrumentation and Methods for Astrophysics (astro-ph.IM)
The ability of digital sky surveys to collect and store very large amounts of data provides completely new ways to study the local universe. Perhaps one of the most provocative observations reported with such tools is the asymmetry between galaxies with clockwise and counterclockwise spin patterns. Here I use $\sim1.7\cdot10^5$ spiral galaxies from SDSS and sort them by their spin patterns (clockwise or counterclockwise) to identify and profile a possible large-scale pattern of the distribution of galaxy spin patterns as observed from Earth. The analysis shows asymmetry between the number of clockwise and counterclockwise spiral galaxies imaged by SDSS, and a dipole axis. These findings largely agree with previous reports using smaller datasets. The probability of the differences between the number of galaxies to occur by chance is (P<4*10^-9), and the probability of an asymmetry axis to occur by mere chance is (P<1.4*10^-5).
- [19] arXiv:2004.02962 [pdf, other]
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Title: The SDSS-HET Survey of Kepler Eclipsing Binaries. Description of the Survey and First ResultsAuthors: Suvrath Mahadevan, Chad F. Bender, Kelly Hambleton, Scott W. Fleming, Rohit Deshpande, Kyle Conroy, Gal Matijevič, Leslie Hebb, Arpita Roy, Hasan Ak, Blaž Leban, Andrej PršaComments: 16 pages, 10 figures, Published 2019 October 1 in ApJJournal-ref: 2019ApJ...884..126MSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)
The Kepler mission has provided a treasure trove of eclipsing binaries (EBs), observed at extremely high photometric precision, nearly continuously for several years. We are carrying out a survey of ~100 of these EBs to derive dynamical masses and radii with precisions of 3% or better. We use multiplexed near-infrared H band spectroscopy from the SDSS-III and -IV APOGEE instrument and optical spectroscopy from the HET High-Resolution Spectrograph to derive double-lined spectroscopic orbits and dynamical mass-ratios for the EB sample. This information is combined with Kepler photometry to derive orbital inclination, dynamical masses of the components, radii and temperatures. These measurements are directly applicable for benchmarking stellar models that are integrating the next generation of improvements, such as the magnetic suppression of convection efficiency, updated opacity tables, and fine-tuned equations of state. We selected our EB sample to include systems with low-mass ($M \lt 0.8 \; M_{\odot}$) primary or secondary components, many expected to populate the relatively sparse parameter space below $0.5 \; M_{\odot}$. In this paper, we describe our EB sample and the analysis techniques we are utilizing, and present masses and radii for two systems that inhabit particularly underpopulated regions of mass-radius-period space: KIC 2445134 and KIC 3003991. Our analysis of KIC 2445134 ($q=0.411 \pm 0.001$) yields masses and radii of $M_A = 1.29 \pm 0.03 \; M_{\odot}$, $M_B = 0.53 \pm 0.01 \; M_{\odot}$, $R_A = 1.42 \pm 0.01 \; R_{\odot}$, $R_B = 0.510 \pm 0.004 \; R_{\odot}$, and a temperature ratio of $T_B/T_A = 0.635 \pm 0.001$; our analysis of KIC 3003991 ($q=0.298 \pm 0.006$) yields $M_A = 0.74 \pm \; 0.04 M_{\odot}$, $M_B = 0.222 \pm \; 0.007 M_{\odot}$, $R_A = 0.84 \pm 0.01 \; R_{\odot}$, $R_B = 0.250 \pm 0.004 \; R_{\odot}$, and a temperature ratio of $T_B/T_A= 0.662 \pm 0.001$.
- [20] arXiv:2004.02963 [pdf, other]
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Title: Multipole alignment in the large-scale distribution of spin direction of spiral galaxiesAuthors: Lior ShamirComments: To be submitted. Comments welcomeSubjects: Astrophysics of Galaxies (astro-ph.GA)
Previous observations have suggested non-random distribution of spin directions of galaxies at scales far larger than the size of a supercluster. Here I use $\sim1.7\cdot10^5$ spiral galaxies from SDSS and $3.3\cdot10^4$ spiral galaxies from Pan-STARRS to analyze the distribution of galaxy spin patterns of spiral galaxies as observed from Earth. The analysis shows in both SDSS and Pan-STARRS that the distribution of galaxy spin directions forms a non-random pattern, and can be fitted to a dipole axis in probability much higher than mere chance. These observations agree with previous findings, but are based on more data and two different telescopes. The analysis also shows that the distribution of galaxy spin directions fits a large-scale multipole alignment, with best fit to quadrupole alignment with probability of $\sim6.9\sigma$ to have such distribution by chance. Comparison of two separate datasets from SDSS and Pan-STARRS such that the galaxies in both datasets have similar redshift distribution provides nearly identical quadrupole patterns.
- [21] arXiv:2004.02968 [pdf, other]
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Title: The $γ$-ray sky seen at X-ray energies I. Searching for the connection between X-rays and $γ$-rays in Fermi BL Lac objectsAuthors: E. J. Marchesini (UniTO, UniLP, INFN-To, CONICET-UNLP, INAF-OATo), A. Paggi (UniTO), F. Massaro (UniTO), N. Masetti (INAF-OAS), R. D'Abrusco (SAO), I. Andruchow (UniLP, CONICET-UniLP), R. de Menezes (UniTO, Universidade de Sao Paulo)Comments: 12 pages, 15 figures, 1 table (pre-proof version), A&A publishedJournal-ref: 2019 A&A, 631A, 150Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Astrophysics of Galaxies (astro-ph.GA)
BL Lac objects are an extreme type of active galactic nuclei (AGNs) that belong to the largest population of $\gamma$-ray sources: blazars. This class of AGNs shows a double-bumped spectral energy distribution that is commonly described in terms of a synchrotron self-Compton (SSC) emission process, whereas the low-energy component that dominates their emission between the infrared and the X-ray band is tightly connected to the high-energy component that peaks in the $\gamma$-rays. Two strong connections that link radio and mid-infrared emission of blazars to the emission in the $\gamma$-ray band are well established. They constitute the basis for associating $\gamma$-ray sources with their low-energy counterparts. We searched for a possible link between X-ray and $\gamma$-ray emissions for the subclass of BL Lacs using all archival Swift/XRT observations combined with Fermi data for a selected sample of 351 sources. Analyzing $\sim$2400 ks of Swift/XRT observations that were carried out until December 2018, we discovered that above the $\gamma$-ray flux threshold $F_{\gamma}\approx3\times10^{-12}\,\rm{erg}\,\rm{cm}^{-2}\,\rm{s}^{-1}$, 96\% of all \emph{Fermi} BL Lacs have an X-ray counterpart that is detected with signal-to-noise ratio higher than 3. We did not find any correlation or clear trend between X-ray and $\gamma$-ray fluxes and/or spectral shapes, but we discovered a correlation between the X-ray flux and the mid-infrared color. Finally, we discuss on a possible interpretation of our results in the SSC framework.
- [22] arXiv:2004.02969 [pdf, other]
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Title: Deciphering the Large-Scale Environment of Radio Galaxies in the Local Universe II. A Statistical Analysis of eEnvironmental PropertiesAuthors: F. Massaro (UniTO, INAF-OATo, INFN-To, CIFS), A. Capetti (INAF-OATo), A. Paggi (UniTO, INAF-OATo, INFN-To), R. D. Baldi (UniTO, Univ. of Southampton), A. Tramacere (Univ. Geneve), I. Pillitteri (INAF-OAPa), R. Campana (INAF-OAS), A. Jimenez-Gallardo (UnitO, INAF-OATo), V. Missaglia (SAO)Comments: 15 pages, 21 figures, 3 tables, ApJS in press (pre-proof version)Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Astrophysics of Galaxies (astro-ph.GA)
In our previous analysis we investigated the large-scale environment of two samples of radio galaxies (RGs) in the local Universe (i.e. with redshifts z<0.15), classified as FR I and FR II on the basis of their radio morphology. The analysis was carried out using i) extremely homogeneous catalogs and ii) a new method, known as cosmological overdensity, to investigate their large-scale environments. We concluded that, independently by the shape of their radio extended structure, RGs inhabit galaxy-rich large-scale environments with similar characteristics and richness. In the present work, we first highlight additional advantages of our procedure, that does not suffer cosmological biases and/or artifacts, and then we carry out an additional statistical test to strengthen our previous results. We also investigate properties of RG environments using those of the cosmological neighbors. We find that large-scale environments of both FRIs and FRIIs are remarkably similar and independent on the properties of central RG. Finally, we highlight the importance of comparing radio sources in the same redshift bins to obtain a complete overview of their large-scale environments.
- [23] arXiv:2004.02993 [pdf, other]
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Title: Mechanochemical synthesis of Aromatic Infrared Band carriers. The top-down chemistry of interstellar carbonaceous dust grain analoguesSubjects: Astrophysics of Galaxies (astro-ph.GA)
Interstellar space hosts nanometre- to micron-sized dust grains. The carbonaceous-rich component of these grain populations emits in infrared bands, observed remotely for decades with telescopes and satellites. They are a key ingredient of astrochemical dust evolution. The precise carriers for most of these bands are still unknown and not well reproduced in the laboratory. In this work, we show the high-energy mechanochemical synthesis of disordered aromatic and aliphatic analogues provides interstellar relevant dust particles. The mechanochemical milling of carbon-based solids under a hydrogen atmosphere produces particles with a spectroscopic match to astrophysical observations of aromatic infrared band (AIB) emission. The H/C ratio for the analogues that best reproduce these astronomical infrared observations lies in the 5$\pm$2% range. This value is much lower than diffuse interstellar hydrogenated amorphous carbons, another Galactic dust grain component observed in absorption, and it most probably provides a constraint on the hydrogenation degree of the most aromatic carbonaceous dust grain carriers. A broad band, observed in AIBs, in the 7.4-8.3 $\mu$m range is correlated to the hydrogen content, and thus the structural evolution in the analogues produced. The mechanochemical process can be seen as an experimental reactor to stimulate local energetic chemical reactions. It introduces bond disorder and hydrogen chemical attachment on the produced defects, with an effect similar to the interstellar space very localised chemical reactions with solids. From the vantage point of astrophysics, these laboratory interstellar dust analogues will be used to predict dust grain evolution under simulated interstellar conditions, including harsh radiative environments. Such interstellar analogues offer an opportunity to derive a global view on the cycling of matter in other star forming systems.
- [24] arXiv:2004.03007 [pdf, other]
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Title: Atmospheric convection plays a key role in the climate of tidally-locked terrestrial exoplanets: insights from high-resolution simulationsAuthors: Denis E. Sergeev, F. Hugo Lambert, Nathan J. Mayne, Ian A. Boutle, James Manners, Krisztian KoharyComments: 26 pages, 15 figures, 5 tables. Accepted to ApJSubjects: Earth and Planetary Astrophysics (astro-ph.EP)
Using a 3D general circulation model (GCM), we investigate the sensitivity of the climate of tidally-locked Earth-like exoplanets, Trappist-1e and Proxima Centauri b, to the choice of a convection parameterization. Compared to a mass-flux convection parameterization, a simplified convection adjustment parameterization leads to a $>$60% decrease of the cloud albedo, increasing the mean day-side temperature by $\approx$10 K. The representation of convection also affects the atmospheric conditions of the night side, via a change in planetary-scale wave patterns. As a result, using the convection adjustment scheme makes the night-side cold traps warmer by 17-36 K for the planets in our simulations. The day-night thermal contrast is sensitive to the representation of convection in 3D GCM simulations, so caution should be taken when interpreting emission phase curves. The choice of convection treatment, however, does not alter the simulated climate enough to result in a departure from habitable conditions, at least for the atmospheric composition and planetary parameters used in our study. The near-surface conditions both in the Trappist-1e and Proxima b cases remain temperate, allowing for an active water cycle. We further advance our analysis using high-resolution model experiments, in which atmospheric convection is simulated explicitly. Our results suggest that in a hypothetical global convection-permitting simulation the surface temperature contrast would be higher than in the coarse-resolution simulations with parameterized convection. In other words, models with parameterized convection may overestimate the inter-hemispheric heat redistribution efficiency.
- [25] arXiv:2004.03022 [pdf, ps, other]
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Title: The 2019 super-Eddington outburst of RX J0209.6-7427: Detection of pulsations and constraints on the magnetic field strengthAuthors: G. Vasilopoulos, P. S. Ray, K. C. Gendreau, P. A. Jenke, G. K. Jaisawal, C. A. Wilson-Hodge, T. E. Strohmayer, D. Altamirano, W. B. Iwakiri, M. T. Wolff, S. Guillot, C. Malacaria, A. L. StevensComments: 10 pages, 8 figures, accepted for publication in MNRASSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
In November 2019, MAXI detected an X-ray outburst from the known Be X-ray binary system RX J0209.6-7427 located in the outer wing of the Small Magellanic Cloud. We followed the outburst of the system with NICER which led to the discovery of X-ray pulsations with a period of 9.3 s. We analyzed simultaneous X-ray data obtained with NuSTAR and NICER allowing us to characterize the spectrum and provide an accurate estimate of its bolometric luminosity. During the outburst the maximum broadband X-ray luminosity of the system reached $1-2\times10^{39}$ erg/s, thus exceeding by about one order of magnitude the Eddington limit for a typical 1.4 $M_{\odot}$ mass neutron star (NS). Monitoring observations with Fermi/GBM and NICER allowed us to study the spin evolution of the NS and compare it with standard accretion torque models. We found that the NS magnetic field should be of the order of $3\times10^{12}$ G. We conclude that RX J0209.6-7427 exhibited one of the brightest outbursts observed from a Be X-ray binary pulsar in the Magellanic Clouds, reaching similar luminosity level to the 2016 outburst of SMC X-3. Despite the super-Eddington luminosity of RX J0209.6-7427, the NS appears to have only a moderate magnetic field strength.
- [26] arXiv:2004.03065 [pdf, ps, other]
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Title: Observations of Binary Stars with the Differential Speckle Survey Instrument. IX. Observations of Known and Suspected Binaries, and a Partial Survey of Be StarsAuthors: Elliott P. Horch, Gerard T. van Belle, James W. Davidson, Jr., Daryl Willmarth, Francis C. Fekel, Matthew Muterspaugh, Dana I. Casetti-Dinescu, Frederick W. Hahne, Nicole M. Granucci, Catherine Clark, Jennifer G. Winters, Justin D. Rupert, Samuel A. Weiss, Nicole M. Colton, Daniel A. Nusdeo, Todd J. HenrySubjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)
We report 370 measures of 170 components of binary and multiple star systems, obtained from speckle imaging observations made with the Differential Speckle Survey Instrument at Lowell Observatory's Discovery Channel Telescope in 2015 through 2017. Of the systems studied, 147 are binary stars, 10 are seen as triple systems, and 1 quadruple system is measured. Seventy-six high-quality non-detections and fifteen newly resolved components are presented in our observations. The uncertainty in relative astrometry appears to be similar to our previous work at Lowell, namely linear measurement uncertainties of approximately 2 mas, and the relative photometry appears to be uncertain at the 0.1 to 0.15 magnitude level. Using these measures and those in the literature, we calculate six new visual orbits, including one for the Be star 66 Oph, and two combined spectroscopic-visual orbits. The latter two orbits, which are for HD 22451 (YSC 127) and HD 185501 (YSC 135), yield individual masses of the components at the level of 2 percent or better, and independent distance measures that in one case agrees with the value found in the Gaia DR2, and in the other disagrees at the 2-$\sigma$ level. We find that HD 22451 consists of an F6V+F7V pair with orbital period of $2401.1 \pm 3.2$ days and masses of $1.342 \pm 0.029$ and $1.236 \pm 0.026$ $ M_{\odot}$. For HD 185501, both stars are G5 dwarfs that orbit one another with a period of $433.94 \pm 0.15$ days, and the masses are $0.898 \pm 0.012$ and $0.876 \pm 0.012$ $ M_{\odot}$. We discuss the details of both the new discoveries and the orbit objects.
- [27] arXiv:2004.03094 [pdf, ps, other]
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Title: Tidal Oscillations of Rotating Hot JupitersAuthors: Umin LeeComments: Accepted for publication in MNRAS; 18 pages, 11 figuresSubjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
We calculate small amplitude gravitational and thermal tides of uniformly rotating hot Jupiters composed of a nearly isentropic convective core and a geometrically thin radiative envelope. We treat the fluid in the convective core as a viscous fluid and solve linearized Navier Stokes equations to obtain tidal responses of the core, assuming that the Ekman number ${\rm Ek}$ is a constant parameter. In the radiative envelope, we take account of the effects of radiative dissipations on the responses. The properties of tidal responses depend on thermal timescales $\tau_*$ in the envelope and Ekman number Ek in the core and on weather the forcing frequency $\omega$ is in the inertial range or not, where the inertial range is defined by $|\omega|\le2\Omega$ for the rotation frequency $\Omega$. If ${\rm Ek}\gtrsim 10^{-7}$, the viscous dissipation in the core is dominating the thermal contributions in the envelope for $\tau_*\gtrsim 1$ day. If ${\rm Ek}\lesssim 10^{-7}$, however, the viscous dissipation is comparable to or smaller than the thermal contributions and the envelope plays an important role to determine the tidal torques. If the forcing is in the inertial range, frequency resonance of the tidal forcing with core inertial modes significantly affects the tidal torques, producing numerous resonance peaks of the torque. Depending on the sign of the torque in the peaks, we suggest that there exist cases in which the resonance with core inertial modes hampers the process of synchronization between the spin and orbital motion of the planets.
- [28] arXiv:2004.03128 [pdf, other]
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Title: The high-energy emission of millisecond pulsarsComments: Draft for a chapter of the book 'Millisecond Pulsars', of the Astrophysics and Space Science Library (ASSL) series edited by Sudip Bhattacharyya, Alessandro Papitto and Dipankar BhattacharyaSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
This chapter provides a phenomenological appraisal of the high-energy emission of millisecond pulsars. We comment on some of their properties as a population, as well as consider the especial cases of transitional pulsars, other redbacks, and black widow systems.
- [29] arXiv:2004.03135 [pdf, other]
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Title: GW Ori: Interactions Between a Triple-star System and its Circumtriple Disk in ActionAuthors: Jiaqing Bi, Nienke van der Marel, Ruobing Dong, Takayuki Muto, Rebecca G. Martin, Jeremy L. Smallwood, Jun Hashimoto, Hauyu Baobab Liu, Hideko Nomura, Yasuhiro Hasegawa, Michihiro Takami, Mihoko Konishi, Munetake Momose, Kazuhiro D. Kanagawa, Akimasa Kataoka, Tomohiro Ono, Michael L. Sitko, Sanemichi Z. Takahashi, Kengo Tomida, Takashi TsukagoshiComments: 14 pages, 5 figures, 1 table; submitted to ApJL on 2020-03-28Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA)
GW Ori is a hierarchical triple system which has a rare circumtriple disk. We present Atacama Large Millimeter/submillimeter Array (ALMA) observations of 1.3 mm dust continuum and 12CO J=2-1 molecular gas emission of the disk. For the first time, we identify three dust rings in the disk at ~46, 188, and 338 AU, with estimated dust mass of ~70-250 Earth mass, respectively. To our knowledge, the outer ring in GW Ori is the largest dust ring ever found in protoplanetary disks. We use visibility modelling of dust continuum to show that the disk has misaligned parts and the innermost dust ring is eccentric. The disk misalignment is also suggested by the CO kinematics modelling. We interpret these substructures as evidence of ongoing dynamical interactions between the triple stars and the circumtriple disk.
- [30] arXiv:2004.03140 [pdf, other]
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Title: Late-Phase Spectropolarimetric Observations of Superluminous Supernova SN 2017egm to Probe the Geometry of the Inner EjectaAuthors: Sei Saito, Masaomi Tanaka, Takashi J. Moriya, Mattia Bulla, Giorgos Leloudas, Cosimo Inserra, Chien-Hsiu Lee, Koji S. Kawabata, Paolo MazzaliComments: 9 pages, 4 figures, accepted for publication in ApJSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR)
We present our spectropolarimetric observations of SN 2017egm, a Type I superluminous supernova (SLSN-I) in a nearby galaxy NGC 3191, with Subaru telescope at 185.0 days after the g-band maximum light. This is the first spectropolarimetric observation for SLSNe at late phases. We find that the degree of the polarization in the late phase significantly changes from that measured at the earlier phase. The spectrum at the late phase shows a strong Ca emission line and therefore we reliably estimate the interstellar polarization component assuming that the emission line is intrinsically unpolarized. By subtracting the estimated interstellar polarization, we find that the intrinsic polarization at the early phase is only ~ 0.2 %, which indicates an almost spherical photosphere, with an axial ratio ~ 1.05. The intrinsic polarization at the late phase increases to ~ 0.8 %, which corresponds to the photosphere with an axial ratio 1.2. A nearly constant position angle of the polarization suggests the inner ejecta are almost axisymmetric. By these observations, we conclude that the inner ejecta are more aspherical than the outer ejecta. It may suggest the presence of a central energy source producing aspherical inner ejecta.
- [31] arXiv:2004.03154 [pdf, ps, other]
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Title: Determination of K4000 of potential blazar candidates among EGRET unidentified gamma-ray sourcesComments: Proceedings paper of IAU S356 "Nuclear Activity in Galaxies Across Cosmic Time" (Ethiopia) accepted to be published under the Cambridge University Press, eds M.Povi\'c, P.Marziani, J.Masegosa, H.Netzer, S.H.Negu and S.B.TessemaSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
Blazars are radio-loud Active Galactic Nuclei (AGN) with relativistic jets oriented towards the observer's line-of-sight. Based on their optical spectra, blazars may be classified as flat-spectrum radio quasars (FSRQs) or BL Lacs. FSRQs are more luminous blazars with both narrow and broad emission and absorption lines, while BL Lacs are less luminous and featureless. Recent studies show that blazars dominate (93%) the already-identified EGRET sources (142), suggesting that among the unidentified sources (129) there could still be faint blazars. Due to the presence of a strong non-thermal component inside their jets, blazars are found to display a weaker depression at 4000 {\AA} (K4000<0.4). In this study, we aimed at determining the K4000 break for a selected sample among the potential blazar candidates from unidentified EGRET sources to confirm their blazar nature. We used two blazar candidates, 3EGJ1800-0146 and 3EGJ1709-0817 associated with radio counterparts, J1802-0207 and J1713-0817, respectively. Their optical counterparts were obtained through spectroscopic observations using Robert Stobie spectrograph (RSS) at the Southern African Large Telescope (SALT) in South Africa. The observed Ca II H & K lines depression at 4000 {\AA} in spectra of these sources show a shallow depression, K4000=0.35+-0.02 and 0.24+-0.01, respectively, suggesting that these sources are blazar candidates. Moreover, the redshifts z=0.165 and 0.26 measured in their spectra confirm the extragalactic nature of these sources.
Keywords: line: identification, radiation mechanisms: non-thermal, techniques: spectroscopic, galaxies: active, galaxies: jets, galaxies: BL Lacertae objects - [32] arXiv:2004.03157 [pdf, ps, other]
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Title: The formation of single neutron-stars from double white-dwarf mergers via accretion-induced collapseComments: 15 pages, 8 figures, accepted by MNRASSubjects: Solar and Stellar Astrophysics (astro-ph.SR)
The merging of double white-dwarfs (WDs) may produce the events of accretion-induced collapse (AIC) and form single neutron stars (NSs). Meanwhile, it is also notable that the recently proposed WD+He subgiant scenario has a significant contribution to the production of massive double WDs, in which the primary WD grows in mass by accreting He-rich material from a He subgiant companion. In this work, we aim to study the binary population synthesis (BPS) properties of AIC events from the double WD mergers by considering the classical scenarios and also the contribution of the WD+He subgiant scenario to the formation of double WDs. Firstly, we provided a dense and large model grid of WD+He star systems for producing AIC events through the double WD merger scenario. Secondly, we performed several sets of BPS calculations to obtain the rates and single NS number in our Galaxy. We found that the rates of AIC events from the double WD mergers in the Galaxy are in the range of 1.4-8.9*10^-3 yr^-1 for all ONe/COWD+ONe/COWD mergers, and in the range of 0.3-3.8*10^-3 yr^-1 when double CO WD mergers are not considered. We also found that the number of single NSs from AIC events in our Galaxy are in the range of 0.1-5.9*10^6. The chirp mass of double WDs for producing AIC events distribute in the range of 0.55-1.25Msun. We estimated that more than half of double WDs for producing AIC events are capable to be observed by the future space-based gravitational wave detectors.
- [33] arXiv:2004.03161 [pdf, ps, other]
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Title: Probing High-Energy Light Dark Matter with IceCubeComments: 16 pages, 6 figures, 1 tableSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Experiment (hep-ex); High Energy Physics - Phenomenology (hep-ph)
The direct detection of particle dark matter through its scattering with nucleons is of fundamental importance to understand the nature of DM. In this work, we propose that the high-energy neutrino detectors like IceCube can be used to uniquely probe the DM-nucleon cross-section for high-energy DM of $\sim$ PeV, up-scattered by the high-energy cosmic rays. We derive for the first time strong constraints on the DM-nucleon cross-section down to $\sim 10^{-32}$ cm$^2$ at this energy scale for sub-GeV DM candidates. Such independent probe at energy scale far exceeding other existing direct detection experiments can therefore provide useful insights complementary to other searches.
- [34] arXiv:2004.03175 [pdf, other]
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Title: Discovery of a Thirty-Degree Long Ultraviolet Arc in Ursa MajorAuthors: A. Bracco, R. A. Benjamin, M.I.R. Alves, A. Lehmann, F. Boulanger, L. Montier, D. Mittelman, D. di Cicco, S. WalkerComments: Accepted by A&A on April 3, 2020Subjects: Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)
Our view of the interstellar medium of the Milky Way and the universe beyond is affected by the structure of the local environment in the Solar neighborhood. Here, we present the discovery of a thirty-degree long arc of ultraviolet emission with a thickness of only a few arcminutes: the Ursa Major Arc. It consists of several arclets seen in the near- and far-ultraviolet bands of the GALEX satellite. A two-degree section of the arc was first detected in the H{\alpha} optical spectral line in 1997; additional sections were seen in the optical by the team of amateur astronomers included in this work. This direction of the sky is known for very low hydrogen column density and dust extinction; many deep fields for extra-galactic and cosmological investigations lie in this direction. Diffuse ultraviolet and optical interstellar emission are often attributed to scattering of light by interstellar dust. The lack of correlation between the Ursa Major Arc and thermal dust emission observed with the Planck satellite, however, suggests that other emission mechanisms must be at play. We discuss the origin of the Ursa Major Arc as the result of an interstellar shock in the Solar neighborhood.
- [35] arXiv:2004.03182 [pdf, other]
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Title: Integral Field Spectroscopy of Planetary Nebulae with MUSEComments: 9 pages, 4 PDF figures, to appear in Proceedings of WORKPLANS II (Lorentz Center Workshop, Leiden, the Netherlands, December 2019), edited by T. Ueta, accepted for publication by GalaxiesSubjects: Astrophysics of Galaxies (astro-ph.GA); Instrumentation and Methods for Astrophysics (astro-ph.IM); Solar and Stellar Astrophysics (astro-ph.SR)
The Multi-Unit Spectroscopic Explorer (MUSE) is a large integral field unit mounted on the ESO Very Large Telescope. Its spatial (60 arcsecond field) and wavelength (4800-9300A) coverage is well suited to detailed imaging spectroscopy of extended planetary nebulae, such as in the Galaxy. An overview of the capabilities of MUSE applied to planetary nebulae (PNe) is provided together with the specific advantages and disadvantages. Some examples of archival MUSE observations of PNe are provided. MUSE datacubes for two targets (NGC 3132 and NGC 7009) have been analysed in detail and they are used to show the advances achievable for planetary nebula studies. Prospects for further MUSE observations of PNe and a broader analysis of existing datasets are outlined.
- [36] arXiv:2004.03192 [pdf, ps, other]
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Title: Discovery of the massive black hole transient MAXI J1348-630Authors: Mayu Tominaga, Satoshi Nakahira, Megumi Shidatsu, Motoki Oeda, Ken Ebisawa, Yasuharu SugawaraComments: 6 pages, 4 figures, submitted to ApJLSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
We report the first half-year monitoring of the new Galactic black hole candidate MAXI J1348-630, discovered on 2019 January 26 with the Gas Slit Camera (GSC) on-board MAXI. During the monitoring period, the source exhibited two peaks, where the first peak flux (at T=14 day from the discovery of T=0) was ~4 Crab (2-20 keV) and the second one (at T=132 day) was ~10 % of that. The source exhibited distinct spectral transitions between the high/soft state and the low/hard state and an apparent ``q''-shape curve on the hardness-intensity diagram, both of which are well-known characteristics of the black hole binaries. Compared to other bright black hole transients, MAXI J1348-630 is characterized by its rather low disk-temperature (~0.75 keV at the maximum) and high peak flux in the high/soft state. The low peak-temperature leads to a large innermost radius that is identified as the innermost stable circular orbit (ISCO) around the black hole. The black hole mass is estimated from the ISCO as ~16 (D / 5kpc) Mo, where D is a distance to the source, assuming the face-on geometry of the accretion disk and a non-spinning black hole. The black hole is considered even more massive if the disk is inclined or the black hole is spinning. The source is in the direction of the Galactic Scutum-Centaurus arm at ~4-8 kpc, of which distance is consistent with the observed hydrogen column density. These inferred mass and distance values go with an empirical relationship between the peak luminosity (L_peak) and the Eddington luminosity (L_Edd), as (L_peak)/(L_Edd)=0.2-0.4. We suggest that MAXI J1348-630 may host the most massive black hole among the known black hole binaries in our Galaxy.
- [37] arXiv:2004.03195 [pdf, ps, other]
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Title: Study of relativistic accretion flow in Kerr-Taub-NUT spacetimeComments: 15 pages, 14 figuresSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
We study the properties of the relativistic accretion flow in a Kerr-Taub-NUT (KTN) spacetime which is characterized by the Kerr parameter ($a_{\rm k}$) and NUT parameter ($n$). Depending on $a_{\rm k}$ and $n$ values, KTN spacetime represents either a black or a naked singularity. We solve the governing equations that describe the relativistic accretion flow in KTN spacetime and obtain all possible global transonic accretion solutions around KTN black hole in terms of the energy $({\cal E})$ and angular momentum $(\lambda)$ of the flow. We identify the region of the parameter space in $\lambda-{\cal E}$ plane that admits the flow to possess multiple critical points for KTN black hole. We examine the modification of the parameter space due to $a_{\rm k}$ and $n$ and find that the role of $a_{\rm k}$ and $n$ in determining the parameter space is opposite to each other. This clearly indicates that the NUT parameter $n$ effectively mitigate the effect of black hole rotation in deciding the accretion flow structure. In addition, we also investigate all possible flow topologies around the naked singularity and find that there exists a region around the naked singularity which remains inaccessible to the flow. We study the critical point properties for naked singularities and find that flow possess maximum of four critical points. Finally, we obtain the parameter space for multiple critical points for naked singularity and find that parameter space is shrunk and shifted to lower $\lambda$ and higher ${\cal E}$ side as $a_{\rm k}$ is increased which ultimately disappears.
- [38] arXiv:2004.03201 [pdf, other]
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Title: Observing Baryonic Acoustic Oscillations in tomographic cosmic shear surveysComments: 5 pages, 4 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
We show that it is possible to build effective matter density power spectra in tomographic cosmic shear observations that exhibit the Baryonic Acoustic Oscillations (BAO) features once a nulling transformation has been applied to the data. The precision with which the amplitude and position of these features can be reconstructed is quantified in terms of sky coverage, intrinsic shape noise, median source redshift and number density of sources. BAO detection in Euclid or LSST like wide surveys will be possible with a modest signal-to-noise ratio. It would improve dramatically for slightly deeper surveys.
- [39] arXiv:2004.03203 [pdf, other]
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Title: Collimated synchrotron threads linking the radio lobes of ESO137-006Authors: M. Ramatsoku, M. Murgia, V. Vacca, P. Serra, S. Makhathini, F. Govoni, O. Smirnov, L. A. L. Andati, E. de Blok, G. I. G. Józsa, P. Kamphuis, D. Kleiner, F. M. Maccagni, D. Cs. Molnár, A. J. T. Ramaila, K. Thorat, S.V. WhiteComments: 5 pages, 4 figures, accepted for publication in A&A lettersSubjects: Astrophysics of Galaxies (astro-ph.GA)
We present MeerKAT 1000 MHz and 1400 MHz observations of a bright radio galaxy in the southern hemisphere, ESO~137-006. The galaxy lies at the centre of the massive and merging Norma galaxy cluster. The MeerKAT continuum images (rms ~0.02 mJy/beam at ~10" resolution) reveal new features that have never been seen in a radio galaxy before: collimated synchrotron threads of yet unknown origin, which link the extended and bent radio lobes of ESO~137-006. The most prominent of these threads stretches in projection for about 80 kpc and is about 1 kpc in width. The radio spectrum of the threads is steep, with a spectral index of up to $\alpha\simeq 2$ between 1000 MHz and 1400 MHz.
- [40] arXiv:2004.03211 [pdf, other]
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Title: Orthogonal pulsars as a key test for pulsar evolutionComments: 14 pages; accepted to MNRASSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
At present, there is no direct information about the evolution of inclination angle $\chi$ between magnetic and rotational axes in radio pulsars. As to theoretical models of pulsar evolution, they predict both the alignment, i.e. evolution of inclination angle $\chi$ to $0^{\circ}$, and its counter-alignment, i.e. evolution to $90^{\circ}$. In this paper, we demonstrate that the statistics of interpulse pulsars can give us the key test to solve the alignment/counter-alignment problem as the number of orthogonal interpulse pulsars ($\chi \approx 90^{\circ}$) drastically depends on the evolutionary trajectory.
- [41] arXiv:2004.03232 [pdf, ps, other]
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Title: On spatial and projected correlation functionsComments: 10 pages, 4 figures, 3 tablesSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
Our goal is to find the relation between the two-point correlation functions of the projected and spatial density fields of galaxies, and their influence to biasing, fractal and other geometrical properties of the cosmic web. Using spatial (3D) and projected (2D) density fields we calculate 3D and 2D correlation functions of galaxies, $\xi(r)$, structure functions, $g(r)=1 +\xi(r)$, and fractal functions, $\gamma(r)= d \log g(r)/ d \log r$, for a biased $\Lambda$ cold dark matter (CDM) simulation. We analyse how these functions describe biasing, fractal and other properties of the cosmic web. We compare the correlation functions of spatial and projected density fields as descriptors of the cosmic web.
Dominant elements of the cosmic web are clusters and filaments, separated by voids filling most of the volume. In individual 2D sheets the positions of clusters and filament do not coincide. As a result, in projection clusters and filaments fill in 2D voids. This leads to the decrease of amplitudes of correlation functions (and power spectra) in projection. For this reason amplitudes of 2D correlation functions are lower than amplitudes of 3D correlation functions, the difference is the larger, the thicker are 2D samples.
Spatial correlation functions of galaxies contain valuable information on geometrical properties of the cosmic web, not available in angular correlation functions. 2D correlation functions do not contain information on voids in 3D density field, thus 3D correlation functions cannot be calculated from 2D correlation functions. - [42] arXiv:2004.03241 [pdf, ps, other]
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Title: A Unique Resource for Solar Flare Diagnostic Studies: the SMM Bent Crystal SpectrometerComments: To be published, Astrophysical JournalSubjects: Solar and Stellar Astrophysics (astro-ph.SR)
The {\em Bent Crystal Spectrometer}\/ (BCS) on the NASA {\em Solar Maximum Mission}\/ spacecraft observed the X-ray spectra of numerous solar flares during the periods 1980 February to November and 1984~--~1989. The instrument, the first of its kind to use curved crystal technology, observed the resonance lines of He-like Ca (\caxix) and Fe (\fexxv) and neighboring satellite lines, allowing the study of the rapid evolution of flare plasma temperature, turbulence, mass motions etc. To date there has not been a solar X-ray spectrometer with comparable spectral and time resolution, while subsequent solar cycles have delivered far fewer and less intense flares. The BCS data archive thus offers an unparalleled resource for flare studies. A recent re-assessment of the BCS calibration and its operations is extended here by using data during a spacecraft scan in the course of a flare on 1980 November~6 that highlights small deformations in the crystal curvature of the important channel~1 (viewing lines of \caxix\ and satellites). The results explain long-standing anomalies in spectral line ratios which have been widely discussed in the past. We also provide an in-flight estimation of the BCS collimator field of view which improves the absolute intensity calibration of the BCS. The BCS channel~1 background is shown to be entirely due to solar continuum radiation, confirming earlier analyses implying a time-variable flare abundance of Ca. We suggest that BCS high-resolution \caxix\ and \fexxv\ line spectra be used as templates for the analysis of X-ray spectra of non-solar sources.
- [43] arXiv:2004.03246 [pdf, other]
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Title: Identification of GRB precursors in Fermi-GBM burstsComments: Submitted to PRLSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
We present an analysis of more than 11 years of Fermi-GBM data in which 217 Gamma-Ray Bursts (GRBs) are found for which their main burst is preceded by a precursor flash. We find that short GRBs ($<$2 s) are ~10 times less likely to produce a precursor than long GRBs. The quiescent time profile is well described by a double Gaussian distribution, indicating that the observed precursors have two distinct physical progenitors. The light curves of the identified precursor GRBs are publicly available in an online catalog (https://icecube.wisc.edu/~grbweb_public/Precursors.html).
- [44] arXiv:2004.03247 [pdf, other]
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Title: Structure of the outer Galactic disc with Gaia-DR2Comments: 19 pages, 21 figures, accepted to be published in A&ASubjects: Astrophysics of Galaxies (astro-ph.GA)
AIMS. We calculate the stellar density using star counts obtained from Gaia DR2 up to a Galactocentric distance R=20 kpc with a deconvolution technique for the parallax errors. Then we analyse the density in order to study the structure of the outer Galactic disc, mainly the warp.
METHODS. In order to carry out the deconvolution, we used the Lucy inversion technique for recovering the corrected star counts. We also used the Gaia luminosity function of stars with $M_G<10$ to extract the stellar density from the star counts.
RESULTS. The stellar density maps can be fitted by an exponential disc in the radial direction $h_r=2.07\pm0.07$ kpc, with a weak dependence on the azimuth, extended up to 20 kpc without any cut-off. The flare and warp are clearly visible. The best fit of a symmetrical S-shaped warp gives $z_w= z_\odot+(37\pm 4.2(stat.)-0.91(syst.))$ pc $(R/R_\odot )^{2.42\pm 0.76(stat.) + 0.129 (syst.)} sin(\phi+9.3\pm 7.37 (stat.) +4.48 (syst.))$ for the whole population. When we analyse the northern and southern warps separately, we obtain an asymmetry of an $\sim25\%$ larger amplitude in the north. This result may be influenced by extinction because the Gaia G band is quite prone to extinction biases. However, we tested the accuracy of the extinction map we used, which shows that the extinction is determined very well in the outer disc. Nevertheless, we recall that we do not know the full extinction error, and neither do we know the systematic error of the map, which may influence the final result.
The analysis was also carried out for very luminous stars alone ($M_G<-2$), which on average represents a younger population. We obtain similar scale-length values, while the maximum amplitude of the warp is $20-30\%$ larger than with the whole population. The north-south asymmetry is maintained. - [45] arXiv:2004.03275 [pdf, other]
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Title: MPI-AMRVAC: a parallel, grid-adaptive PDE toolkitComments: 31 pages, 13 figures, accepted for publication by Computers and Mathematics with Applications (CAMWA-10131)Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Computational Physics (physics.comp-ph)
We report on the latest additions to our open-source, block-grid adaptive framework MPI-AMRVAC, which is a general toolkit for especially hyperbolic/parabolic partial differential equations (PDEs). Applications traditionally focused on shock-dominated, magnetized plasma dynamics described by either Newtonian or special relativistic (magneto)hydrodynamics, but its versatile design easily extends to different PDE systems. Here, we demonstrate applications covering any-dimensional scalar to system PDEs, with e.g. Korteweg-de Vries solutions generalizing early findings on soliton behaviour, shallow water applications in round or square pools, hydrodynamic convergence tests as well as challenging computational fluid and plasma dynamics applications. The recent addition of a parallel multigrid solver opens up new avenues where also elliptic constraints or stiff source terms play a central role. This is illustrated here by solving several multi-dimensional reaction-diffusion-type equations. We document the minimal requirements for adding a new physics module governed by any nonlinear PDE system, such that it can directly benefit from the code flexibility in combining various temporal and spatial discretisation schemes. Distributed through GitHub, MPI-AMRVAC can be used to perform 1D, 1.5D, 2D, 2.5D or 3D simulations in Cartesian, cylindrical or spherical coordinate systems, using parallel domain-decomposition, or exploiting fully dynamic block quadtree-octree grids.
- [46] arXiv:2004.03279 [pdf, ps, other]
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Title: A global view on the colliding-wind binary WR 147Comments: Accepted for publication in MNRAS; 15 pages, 11 figures, 2 tablesSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)
We present results from a global view on the colliding-wind binary WR 147. We analysed new optical spectra of WR 147 obtained with Gran Telescopio CANARIAS and archive spectra from the Hubble Space Telescope by making use of modern atmosphere models accounting for optically thin clumping. We adopted a grid-modelling approach to derive some basic physical characteristics of both stellar components in WR 147. For the currently accepted distance of 630 pc to WR 147, the values of mass-loss rate derived from modelling its optical spectra are in acceptable correspondence with that from modelling its X-ray emission. However, they give a lower radio flux than observed. A plausible solution for this problem could be if the volume filling factor at large distances from the star (radio-formation region) is smaller than close to the star (optical-formation region). Adopting this, the model can match well both optical and thermal radio emission from WR 147. The global view on the colliding-wind binary WR 147 thus shows that its observational properties in different spectral domains can be explained in a self-consistent physical picture.
- [47] arXiv:2004.03305 [pdf, other]
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Title: Probing cosmic isotropy with a new X-ray galaxy cluster sample through the $L_{\text{X}}-T$ scaling relationComments: To appear in A&A, April 2020 (44 pages with Appendix, 34 figures), Press releases from NASA/Chandra, ESA, Uni. of BonnSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
The isotropy of the late Universe is an assumption greatly used in astronomy. However, many studies have recently reported deviations from isotropy with a definitive conclusion yet to be made. New, independent methods to robustly test the cosmic isotropy are of crucial importance. In this work, we investigate the directional behavior of the X-ray luminosity-temperature ($L_X-T$) relation of galaxy clusters. A tight correlation exists between the luminosity and temperature of the X-ray-emitting intracluster medium. While the measured luminosity depends on the underlying cosmology, the temperature can be determined without any cosmological assumptions. By exploiting this property one can effectively test the isotropy of cosmological parameters over the full extragalactic sky. Here, we used 313 homogeneously selected X-ray galaxy clusters from the MCXC catalog and obtained core-excised temperatures for all of them. We find that the behavior of the $L_X-T$ relation heavily depends on the direction of the sky. Strong anisotropies are detected at a $\sim 4\sigma$ level toward $(l,b)\sim (280^{\circ}, -20^{\circ})$. Several X-ray and cluster-related effects that could potentially explain these anisotropies were examined, but none did so. Interestingly, two other available cluster samples appear to have a similar behavior throughout the sky, while being fully independent of each other and our sample. Performing a joint analysis of the three samples, the final anisotropy is further intensified ($\sim 5\sigma$), toward $(l,b)\sim (303^{\circ}, -27^{\circ})$, which is in good agreement with other cosmological probes. This result demonstrates that X-ray galaxy cluster studies that assume perfect isotropy can produce strongly biased results whether the underlying reason is cosmological or related to X-rays. The identification of the exact nature of these anisotropies is therefore crucial.
- [48] arXiv:2004.03306 [pdf, ps, other]
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Title: Very high energy $γ$-ray emission from two blazars of unknown redshift and upper limits on their distanceAuthors: H.E.S.S. Collaboration, H. Abdalla, R. Adam, F. Aharonian, F. Ait Benkhali, E.O. Angüner, M. Arakawa, C. Arcaro, C. Armand, T. Armstrong, H. Ashkar, M. Backes, V. Baghmanyan, V. Barbosa Martins, A. Barnacka, M. Barnard, Y. Becherini, D. Berge, K. Bernlöhr, M. Böttcher, C. Boisson, J. Bolmont, S. Bonnefoy, J. Bregeon, M. Breuhaus, F. Brun, P. Brun, M. Bryan, M. Büchele, T. Bulik, T. Bylund, S. Caroff, A. Carosi, S. Casanova, T. Chand, S. Chandra, A. Chen, G. Cotter, M. Curyło, I.D. Davids, J. Davies, C. Deil, J. Devin, P. deWilt, L. Dirson, A. Djannati-Ataï, A. Dmytriiev, A. Donath, V. Doroshenko, J. Dyks, K. Egberts, F. Eichhorn, G. Emery, J.-P. Ernenwein, K. Feijen, S. Fegan, A. Fiasson, G. Fontaine, S. Funk, M. Füßling, S. Gabici, Y.A. Gallant, G. Giavitto, et al. (166 additional authors not shown)Comments: In press in MNRAS. 13 pages, 4 figuresSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
We report on the detection of very-high-energy (VHE; $E > 100$~GeV) $\gamma$-ray emission from the BL Lac objects KUV 00311-1938 and PKS 1440-389 with the High Energy Stereoscopic System (H.E.S.S.). H.E.S.S. observations were accompanied or preceded by multi-wavelength observations with Fermi/LAT, XRT and UVOT on board the Swift satellite, and ATOM. Based on an extrapolation of the Fermi/LAT spectrum towards the VHE $\gamma$-ray regime, we deduce a 95% confidence level upper limit on the unknown redshift of KUV 00311-1938 of z < 0.98, and of PKS 1440-389 of z < 0.53. When combined with previous spectroscopy results the redshift of KUV 00311-1938 is constrained to $0.51 \leq z < 0.98$ and for PKS 1440-389 to $0.14 \lessapprox z < 0.53$.
- [49] arXiv:2004.03310 [pdf, other]
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Title: Spectroscopic properties of radio-loud and radio-quiet quasarsComments: Proceedings paper of the IAU symposium "Nuclear Activity in Galaxies Across Cosmic Time" (Ethiopia) accepted to be published under the Cambridge University Press, eds. M. Povic, P. Marziani, J. Masegosa, H. Netzer, S. H. Negu, and S. B. TessemaSubjects: Astrophysics of Galaxies (astro-ph.GA)
Surveys have shown radio-loud (RL) quasars constitute 10%-15% of the total quasar population and rest are radio-quiet (RQ). However, it is unknown if this radio-loud fraction (RLF) remains consistent among different parameter spaces. This study shows that RLF increases for increasing full width half maximum (FWHM) velocity of the H$\beta$ broad emission line (z < 0.75). To analyse the reason, we compared bolometric luminosity of RL and RQ quasars sample which have FWHM of H$\beta$ broad emission line greater than 15000km/s (High Broad Line or HBL) with which have FWHM of H$\beta$ emission line less than 2500km/s (Low Broad Line or LBL). From the distributions we can conclude for the HBL, RQ and RL quasars are peaking separately and RL quasars are having higher values whereas for the LBL the peaks are almost indistinguishable. We predicted selection effects could be the possible reason but to conclude anything more analysis is needed. Then we compared our result with Wills & Browne (1986) and have shown that some objects from our sample do not follow the pattern of the logR vs FWHM plot where R is the ratio of 5 GHz radio core flux density with the extended radio lobe flux density.
- [50] arXiv:2004.03425 [pdf, other]
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Title: Elemental abundances in M31: [Fe/H] and [α/Fe] in M31 Dwarf Galaxies Using Coadded SpectraAuthors: Jennifer Wojno, Karoline M. Gilbert, Evan N. Kirby, Ivanna Escala, Rachael M. Beaton, Erik J. Tollerud, Steven R. Majewski, Puragra GuhathakurtaComments: 34 pages, 17 figures. Submitted to ApJSubjects: Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)
We present chemical abundances of red giant branch (RGB) stars in the dwarf spheroidal (dSph) satellite system of Andromeda (M31), using spectral synthesis of medium resolution (R $\sim 6000$) spectra obtained with the Keck II telescope and DEIMOS spectrograph via the Spectroscopic and Photometric Landscape of Andromeda's Stellar Halo (SPLASH) survey. We coadd stars according to their similarity in photometric metallicity or effective temperature to obtain a signal-to-noise ratio (S/N) high enough to measure average [Fe/H] and [$\alpha$/Fe] abundances. We validate our method using high S/N spectra of RGB stars in Milky Way globular clusters as well as deep observations for a subset of the M31 dSphs in our sample. For this set of validation coadds, we compare the weighted average abundance of the individual stars with the abundance determined from the coadd. We present individual and coadded measurements of [Fe/H] and [$\alpha$/Fe] for stars in ten M31 dSphs, including the first [$\alpha$/Fe] measurements for And IX, XIV, XV, and XVIII. These fainter, less massive dSphs show declining [$\alpha$/Fe] relative to [Fe/H], implying an extended star formation history. In addition, these dSphs also follow the same mass-metallicity relation found in other Local Group satellites. The conclusions we infer from coadded spectra agree with those from previous measurements in brighter M31 dSphs with individual abundance measurements, as well as conclusions from photometric studies. These abundances greatly increase the number of spectroscopic measurements of the chemical composition of M31's less massive dwarf satellites, which are crucial to understanding their star formation history and interaction with the M31 system.
- [51] arXiv:2004.03435 [pdf, other]
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Title: Obscured $pp$-channel neutrino sourcesComments: 30 pages, 10 figures. Submitted to Physical Review D. Previously shown in a PhD thesis (arXiv:1911.12244)Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Phenomenology (hep-ph)
We explore the possibility that the astrophysical neutrinos are produced in $pp$-interactions with a gas cloud near the source acting as a beam dump, which is sufficiently dense to significantly attenuate the associated gamma-ray flux through pair-production on this gas. In this way, such sources could potentially supply the astrophysical neutrino flux whilst avoiding the existing constraints on the non-blazar contribution to the extragalactic gamma-ray background. After defining our model, we implement a Monte Carlo simulation and apply this to different scenarios. First, we investigate a set of active galaxies which exhibit signs of obscuration. We find that, currently, the expected neutrino flux from these objects in our model is below the existing exclusion limits, but can already constrain the amount of protons accelerated in such sources. Second, we investigate the diffuse neutrino flux generated by a population of obscured sources. We find that such a population can indeed alleviate the tension with the extragalactic background light. We discuss the possibility that ultra-luminous infrared galaxies represent such a source class.
- [52] arXiv:2004.03467 [pdf, ps, other]
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Title: Aerosol characterization using satellite remote sensing of light pollution sources at nightComments: Author prepared version of a manuscript accepted for publication in Monthly Notices of the Royal Astronomical Society (Letter) 5 pages, 5 figuresSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Atmospheric and Oceanic Physics (physics.ao-ph)
A demanding challenge in atmospheric research is the night-time characterization of aerosols using passive techniques, that is, by extracting information from scattered light that has not been emitted by the observer. Satellite observations of artificial night-time lights have been used to retrieve some basic integral parameters, like the aerosol optical depth. However, a thorough analysis of the scattering processes allows one to obtain substantially more detailed information on aerosol properties. In this Letter we demonstrate a practicable approach for determining the aerosol particle size number distribution function in the air column, based on the measurement of the angular radiance distribution of the scattered light emitted by night-time lights of cities and towns, recorded from low Earth orbit. The method is self-calibrating and does not require the knowledge of the absolute city emissions. The input radiance data are readily available from several spaceborne platforms, like the VIIRS-DNB radiometer onboard the Suomi-NPP satellite.
- [53] arXiv:2004.03471 [pdf, other]
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Title: The single-sided pulsator CO~CamelopardalisAuthors: D. W. Kurtz, G. Handler, S. A. Rappaport, H. Saio, J. Fuller, T. Jacobs, A. Schmitt, D. Jones, A. Vanderburg, D. LaCourse, L. Nelson, F. Kahraman Aliçavuş, M. GiarrussoComments: 18 pages, 18 figuresSubjects: Solar and Stellar Astrophysics (astro-ph.SR)
CO~Cam (TIC 160268882) is the second ``single-sided pulsator'' to be discovered. These are stars where one hemisphere pulsates with a significantly higher amplitude than the other side of the star. CO~Cam is a binary star comprised of an Am $\delta$~Sct primary star with $T_{\rm eff} = 7070 \pm 150$\,K, and a spectroscopically undetected G main-sequence secondary star. The dominant pulsating side of the primary star is centred on the L$_1$ point. We have modelled the spectral energy distribution combined with radial velocities, and independently the {\em TESS} light curve combined with radial velocities. Both of these give excellent agreement and robust system parameters for both stars. The $\delta$~Sct star is an oblique pulsator with at least four low radial overtone (probably) f~modes with the pulsation axis coinciding with the tidal axis of the star, the line of apsides. Preliminary theoretical modelling indicates that the modes must produce much larger flux perturbations near the L$_1$ point, although this is difficult to understand because the pulsating star does not come near to filling its Roche lobe. More detailed models of distorted pulsating stars should be developed. These newly discovered single-sided pulsators offer new opportunities for astrophysical inference from stars that are oblique pulsators in close binary stars.
- [54] arXiv:2004.03475 [pdf, other]
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Title: Gas phase Elemental abundances in Molecular cloudS (GEMS). II. On the quest for the sulphur reservoir in molecular clouds: the $H_{2}S$ caseAuthors: D. Navarro-Almaida, R. Le Gal, A. Fuente, P. Rivière-Marichalar, V. Wakelam, S. Cazaux, P. Caselli, Jacob C. Laas, T. Alonso-Albi, J. C. Loison, M. Gerin, C. Kramer, E. Roueff, R. Bachiller, B. Commerçon, R. Friesen, S. García-Burillo, J. R. Goicoechea, B. M. Giuliano, I. Jiménez-Serra, J. M. Kirk, V. Lattanzi, J. Malinen, N. Marcelino, R. Martín-Domènech, G. M. Muñoz Caro, J. Pineda, B. Tercero, S. P. Treviño Morales, O. Roncero, A. Hacar, M. Tafalla, D. Ward-ThompsonComments: 23 pages, 16 figuresSubjects: Astrophysics of Galaxies (astro-ph.GA)
Sulphur is one of the most abundant elements in the Universe. Surprisingly, sulphuretted molecules are not as abundant as expected in the interstellar medium, and the identity of the main sulphur reservoir is still an open question. Our goal is to investigate the H$_{2}$S chemistry in dark clouds, as this stable molecule is a potential sulphur reservoir. Using millimeter observations of CS, SO, H$_{2}$S, and their isotopologues, we determine the physical conditions and H$_{2}$S abundances along the cores TMC 1-C, TMC 1-CP, and Barnard 1b. The gas-grain model Nautilus is then used to model the sulphur chemistry and explore the impact of photo-desorption and chemical desorption on the H$_2$S abundance. Our model shows that chemical desorption is the main source of gas-phase H$_2$S in dark cores. The measured H$_{2}$S abundance can only be fitted if we assume that the chemical desorption rate decreases by more than a factor of 10 when $n_{\rm H}>2\times10^{4}$. This change in the desorption rate is consistent with the formation of thick H$_2$O and CO ice mantles on grain surfaces. The observed SO and H$_2$S abundances are in good agreement with our predictions adopting an undepleted value of the sulphur abundance. However, the CS abundance is overestimated by a factor of $5-10$. Along the three cores, atomic S is predicted to be the main sulphur reservoir. We conclude that the gaseous H$_2$S abundance is well reproduced, assuming undepleted sulphur abundance and chemical desorption as the main source of H$_2$S. The behavior of the observed H$_{2}$S abundance suggests a changing desorption efficiency, which would probe the snowline in these cores. Our model, however, overestimates the observed gas-phase CS abundance. Given the uncertainty in the sulphur chemistry, our data are consistent with a cosmic elemental S abundance with an uncertainty of a factor of 10.
- [55] arXiv:2004.03492 [pdf, other]
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Title: The impact of pebble flux regulated planetesimal formation on giant planet formationSubjects: Earth and Planetary Astrophysics (astro-ph.EP)
Forming gas giant planets by the accretion of 100 km diameter planetesimals, a typical size that results from self-gravity assisted planetesimal formation, is often thought to be inefficient. Many models therefore use small km-sized planetesimals, or invoke the accretion of pebbles. Furthermore, models based on planetesimal accretion often use the ad hoc assumption of planetesimals distributed radially in a minimum mass solar nebula fashion. We wish to investigate the impact of various initial radial density distributions in planetesimals with a dynamical model for the formation of planetesimals on the resulting population of planets. In doing so, we highlight the directive role of the early stages of dust evolution into pebbles and planetesimals in the circumstellar disk on the following planetary formation. We have implemented a two population model for solid evolution and a pebble flux regulated model for planetesimal formation into our global model for planet population synthesis. This framework is used to study the global effect of planetesimal formation on planet formation. As reference, we compare our dynamically formed planetesimal surface densities with ad-hoc set distributions of different radial density slopes of planetesimals. Even though required, it is not solely the total planetesimal disk mass, but the planetesimal surface density slope and subsequently the formation mechanism of planetesimals, that enables planetary growth via planetesimal accretion. Highly condensed regions of only 100 km sized planetesimals in the inner regions of circumstellar disks can lead to gas giant growth. Pebble flux regulated planetesimal formation strongly boosts planet formation, because it is a highly effective mechanism to create a steep planetesimal density profile. We find this to lead to the formation of giant planets inside 1 au by 100 km already by pure planetesimal accretion.
- [56] arXiv:2004.03504 [pdf, other]
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Title: The CARMA-NRO Orion Survey: Protostellar Outflows, Energetics, and Filamentary AlignmentAuthors: Jesse R. Feddersen, Héctor G. Arce, Shuo Kong, Sümeyye Suri, Álvaro Sánchez-Monge, Volker Ossenkopf-Okada, Michael M. Dunham, Fumitaka Nakamura, Yoshito Shimajiri, John BallyComments: 22 pages, 11 figures in main text, 47 additional figures in appendices. Accepted to ApJSubjects: Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)
We identify 45 protostellar outflows in CO maps of the Orion A giant molecular cloud from the CARMA-NRO Orion survey. Our sample includes 11 newly detected outflows. We measure the mass and energetics of the outflows, including material at low-velocities by correcting for cloud contributions. The total momentum and kinetic energy injection rates of outflows is comparable to the turbulent dissipation rate of the cloud. We also compare the outflow position angles to the orientation of C$^{18}$O filaments. We find that the full sample of outflows is consistent with being randomly oriented with respect to the filaments. A subsample of the most reliable measurements shows a moderately perpendicular outflow-filament alignment which may reflect accretion of mass across filaments and onto the protostellar cores.
- [57] arXiv:2004.03511 [pdf, other]
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Title: Towards An Integrated Optical Transient UtilityAuthors: S. R. KulkarniComments: To be submitted to PASPSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); High Energy Astrophysical Phenomena (astro-ph.HE)
The ongoing optical time-domain astronomy surveys are routinely reporting fifty transient candidates per night. Here, I investigate the demographics of astronomical transients and supernova classifications reported to the Transient Name Server in the year 2019. I find that only a tenth of the transients were spectrally classified. This severe "bottleneck" problem should concern astronomers and also funding agencies. Here, after undertaking a detailed investigation of this issue I offer some solutions. Going forward, astronomers will employ two different methodologies: (1) multi-band photometric method which is well suited to the study of very large, many tens of thousands, samples of faint transients; (2) spectral classifications of thousands of bright transients found in shallow and nightly cadenced wide-field photometry surveys and transients associated with galaxies in the local Universe. The latter program, in addition to unearthing new types of transients and offering astronomers opportunities to undertake extensive follow up of interesting transients, are needed to set the stage for the former. Specifically, I suggest a globally coordinated effort to spectrally classify a complete sample of bright supernovae (less than about 19.5 mag) and transients within the local Universe (radius less than 200 Mpc). The proposed program is within reach, thanks to the on-going wide-field surveys, the development of novel spectrographs tuned for classification, great improvements in throughput of spectrographs and the increasing availability of robotic telescopes.
- [58] arXiv:2004.03514 [pdf, other]
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Title: Identification of MHD compressible modes in interstellar plasma with synchrotron emission polarizationSubjects: Astrophysics of Galaxies (astro-ph.GA); Plasma Physics (physics.plasm-ph)
We provide a procedure for identification of dominating compressible and Alfvenic MHD modes or isotropic turbulence in synchrotron emission polarization maps of Galactic objects. The results for the region of North Galactic Pole, Orion molecular cloud complex and the star-forming complex Cygnus X are presented.
- [59] arXiv:2004.03551 [pdf, other]
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Title: Optical to near-infrared transmission spectrum of the warm sub-Saturn HAT-P-12bAuthors: Ian Wong, Björn Benneke, Peter Gao, Heather A. Knutson, Yayaati Chachan, Gregory W. Henry, Drake Deming, Tiffany Kataria, Graham K. H. Lee, Nikolay Nikolov, David K. Sing, Gilda E. Ballester, Nathaniel J. Baskin, Hannah R. Wakeford, Michael H. WilliamsonComments: 25 pages, 19 figures, accepted for publication in AJSubjects: Earth and Planetary Astrophysics (astro-ph.EP)
We present the transmission spectrum of HAT-P-12b through a joint analysis of data obtained from the Hubble Space Telescope Space Telescope Imaging Spectrograph (STIS) and Wide Field Camera 3 (WFC3) and Spitzer, covering the wavelength range 0.3-5.0 $\mu$m. We detect a muted water vapor absorption feature at 1.4 $\mu$m attenuated by clouds, as well as a Rayleigh scattering slope in the optical indicative of small particles. We interpret the transmission spectrum using both the state-of-the-art atmospheric retrieval code SCARLET and the aerosol microphysics model CARMA. These models indicate that the atmosphere of HAT-P-12b is consistent with a broad range of metallicities between several tens to a few hundred times solar, a roughly solar C/O ratio, and moderately efficient vertical mixing. Cloud models that include condensate clouds do not readily generate the sub-micron particles necessary to reproduce the observed Rayleigh scattering slope, while models that incorporate photochemical hazes composed of soot or tholins are able to match the full transmission spectrum. From a complementary analysis of secondary eclipses by Spitzer, we obtain measured depths of $0.042\%\pm0.013\%$ and $0.045\%\pm0.018\%$ at 3.6 and 4.5 $\mu$m, respectively, which are consistent with a blackbody temperature of $890^{+60}_{-70}$ K and indicate efficient day-night heat recirculation. HAT-P-12b joins the growing number of well-characterized warm planets that underscore the importance of clouds and hazes in our understanding of exoplanet atmospheres.
- [60] arXiv:2004.03562 [pdf, other]
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Title: Fermi Large Area Telescope Observations of the Fast-dimming Crab Nebula in 60-600 MeVComments: Re-submitted to A&A, revised in response to a referee reportSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
Context: The Crab pulsar and its nebula are the origin of relativistic electrons which can be observed through their synchrotron and inverse Compton emission. The transition between synchrotron-dominated and inverse-Compton-dominated emissions takes place at $\approx 10^9$~eV. Aims: The short-term (weeks to months) flux variability of the synchrotron emission from the most energetic electrons is investigated with data from ten years of observations with the Fermi Large Area Telescope (LAT) in the energy range from 60~MeV to 600 MeV. Methods: The off-pulse light-curve has been reconstructed from phase-resolved data. The corresponding histogram of flux measurements is used to identify distributions of flux-states and the statistical significance of a lower-flux component is estimated with dedicated simulations of mock light-curves. The energy spectra for different flux states are reconstructed. Results: We confirm the presence of flaring-states which follow a log-normal flux distribution. Additionally, we discover a low-flux state where the flux drops to less than 16.8~\% of the time-averaged flux and stays there for several weeks. The transition time is observed to be as short as 2 days. The energy spectrum during the low-flux state resembles the extrapolation of the inverse-Compton spectrum measured at energies beyond several GeV energy, implying near quiescence in the high-energy part of the synchrotron emission. Conclusions: The low-flux state found here and the transition time of at most 10 days indicate that the bulk ($>75$\%) of the synchrotron emission above $10^8$~eV originates in a compact volume with apparent angular size of $\theta\approx0.4"~t_\mathrm{var}/(5~\mathrm{d})$. We tentatively identify the so-called inner knot feature as the origin of the bulk of the gamma-ray emission as predicted by Komissarov & Lyutikov (2011).
- [61] arXiv:2004.03574 [pdf, other]
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Title: The integrated angular bispectrumComments: 38 pages, 14 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
We study the position-dependent power spectrum and the integrated bispectrum statistic for 2D cosmological fields on the sphere (integrated angular bispectrum). First, we derive a useful, $m$-independent, formula for the full-sky integrated angular bispectrum, based on the construction of azimuthally symmetric patches. We then implement a pipeline for integrated angular bispectrum estimation, including a mean-field correction to account for spurious isotropy-breaking effects in realistic conditions (e.g., inhomogenous noise, sky masking). Finally, we show examples of applications of this estimator to CMB analysis, both using simulations and actual Planck data. Such examples include $f_\mathrm{NL}$ estimation, analyses of non-Gaussianity from secondary anisotropies (ISW-lensing and ISW-tSZ-tSZ bispectra) and studies of non-Gaussian signatures from foreground contamination.
Cross-lists for Wed, 8 Apr 20
- [62] arXiv:2004.02887 (cross-list from hep-ph) [pdf, other]
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Title: Gauge Boson Signals at the Cosmological ColliderComments: 25 pagesSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)
We study the production of massive gauge bosons during inflation from the axion-type coupling to the inflaton and the corresponding oscillatory features in the primordial non-Gaussianity. In a window in which both the gauge boson mass and the chemical potential are large, the signal is potentially reachable by near-future large scale structure probes. This scenario covers a new region in oscillation frequency which is not populated by previously known cosmological collider models. We also demonstrate how to properly include the exponential factor and discuss the subtleties in obtaining power dependence of the gauge boson mass in the signal estimate.
- [63] arXiv:2004.02889 (cross-list from hep-ph) [pdf, other]
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Title: Fingerprint of Low-Scale Leptogenesis in the Primordial Gravitational-Wave SpectrumComments: 7 pages, 2 figures, 1 tableSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc)
The dynamical generation of right-handed-neutrino (RHN) masses in the early Universe naturally entails the formation of cosmic strings that give rise to an observable signal in gravitational waves (GWs). Here, we show that a characteristic break in the GW spectrum would provide evidence for a new stage in the cosmological expansion history and a suppression of the RHN mass scale compared to the scale of spontaneous symmetry breaking. The detection of such a spectral feature would thus represent a novel and unique possibility to probe RHN masses relevant for low-scale leptogenesis.
- [64] arXiv:2004.02893 (cross-list from hep-th) [pdf, other]
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Title: Hairy Black-holes in Shift-symmetric TheoriesAuthors: Paolo Creminelli, Nicolás Loayza, Francesco Serra, Enrico Trincherini, Leonardo G. TrombettaComments: 24 pagesSubjects: High Energy Physics - Theory (hep-th); Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc)
Scalar hair of black holes in theories with a shift symmetry are constrained by the no-hair theorem of Hui and Nicolis, assuming spherical symmetry, time-independence of the scalar field and asymptotic flatness. The most studied counterexample is a linear coupling of the scalar with the Gauss-Bonnet invariant. However, in this case the norm of the shift-symmetry current $J^2$ diverges at the horizon casting doubts on whether the solution is physically sound. We show that this is not an issue since $J^2$ is not a scalar quantity, since $J^\mu$ is not a diff-invariant current in the presence of Gauss-Bonnet. The same theory can be written in Horndeski form with a non-analytic function $G_5 \sim \log X$. In this case the shift-symmetry current is diff-invariant, but contains powers of $X$ in the denominator, so that its divergence at the horizon is again immaterial. We confirm that other hairy solutions in the presence of non-analytic Horndeski functions are pathological, featuring divergences of physical quantities as soon as one departs from time-independence and spherical symmetry. We generalise the no-hair theorem to Beyond Horndeski and DHOST theories, showing that the coupling with Gauss-Bonnet is necessary to have hair.
- [65] arXiv:2004.02896 (cross-list from gr-qc) [pdf, ps, other]
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Title: Dark energy in multi-fractional spacetimesComments: 1+26 pages, 7 figures, 2 tablesSubjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)
We study the possibility to obtain cosmological late-time acceleration from a geometry changing with the scale, in particular, in the so-called multi-fractional theories with q-derivatives and with weighted derivatives. In the theory with q-derivatives, the luminosity distance is the same as in general relativity and, therefore, geometry cannot act as dark energy. In the theory with weighted derivatives, geometry alone is able to sustain a late-time acceleration phase without fine tuning, while being compatible with structure-formation and big-bang nucleosynthesis bounds. This suggests to extend the theory, in a natural way, from just small-scale to also large-scale modifications of gravity. Surprisingly, the Hausdorff dimension of spacetime is constrained to be close to the topological dimension 4. Promoting this finding to a principle, we conclude that present-day acceleration can be regarded as the effect of a new restoration law for spacetime geometry.
- [66] arXiv:2004.03009 (cross-list from physics.space-ph) [pdf, other]
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Title: Parker Solar Probe observations of proton beams simultaneous with ion-scale wavesAuthors: J. L. Verniero, D. E. Larson, R. Livi, A. Rahmati, M. D. McManus, P. Sharma Pyakurel, K. G. Klein, T. A. Bowen, J. W. Bonnell, B. L. Alterman, P. L. Whittlesey, David M. Malaspina, S. D. Bale, J. C. Kasper, A. W. Case, K. Goetz, P. R. Harvey, K. E. Korreck, R. J. MacDowall, M. Pulupa, M. L. Stevens, T. Dudok de WitComments: 24 pages, 9 figures, 2 tablesSubjects: Space Physics (physics.space-ph); Solar and Stellar Astrophysics (astro-ph.SR)
Parker Solar Probe (PSP), NASA's latest and closest mission to the Sun, is on a journey to investigate fundamental enigmas of the inner heliosphere. This paper reports initial observations made by the Solar Probe Analyzer for Ions (SPAN-I), one of the instruments in the Solar Wind Electrons Alphas and Protons (SWEAP) instrument suite. We address the presence of secondary proton beams in concert with ion-scale waves observed by FIELDS, the electromagnetic fields instrument suite. We show two events from PSP's 2nd orbit that demonstrate signatures consistent with wave-particle interactions. We showcase 3D velocity distribution functions (VDFs) measured by SPAN-I during times of strong wave power at ion-scales. From an initial instability analysis, we infer that the VDFs departed far enough away from local thermodynamic equilibrium (LTE) to provide sufficient free energy to locally generate waves. These events exemplify the types of instabilities that may be present and, as such, may guide future data analysis characterizing and distinguishing between different wave-particle interactions.
- [67] arXiv:2004.03039 (cross-list from nucl-th) [pdf, other]
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Title: QCD Phase Diagrams with Charge and Isospin Axes under Heavy-Ion Collision and Stellar ConditionsSubjects: Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); High Energy Physics - Phenomenology (hep-ph)
We investigate the phase transition from hadron to quark matter in the general case without the assumption of chemical equilibrium with respect to weak decays. The effects of net strangeness on charge and isospin fractions, chemical potentials, and temperature are studied in the context of the Chiral Mean Field (CMF) model that incorporates chiral symmetry restoration and deconfinement. The extent to which these quantities are probed during deconfinement in conditions expected to exist in protoneutron stars, binary neutron-star mergers, and heavy-ion collisions is analyzed quantitatively via the construction of 3-dimensional phase diagrams.
- [68] arXiv:2004.03043 (cross-list from gr-qc) [pdf, ps, other]
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Title: Viable Constraint on Scalar Field in Scalar-Tensor TheoryComments: 18 pages, 2 figures, accepted for publication in Classical and Quantum GravitySubjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
The scalar-tensor theory can be formulated in both Jordan and Einstein frames, which are conformally related together with a redefinition of the scalar field. As the solution to the equation of the scalar field in the Jordan frame does not have the one-to-one correspondence with that in the Einstein frame, we give a criterion along with some specific models to check if the scalar field in the Einstein frame is viable or not by confirming whether this field is reversible back to the Jordan frame. We further show that the criterion in the first parameterized post-Newtonian approximation can be determined by the parameters of the osculating approximation of the coupling function in the Einstein frame and can be treated as a viable constraint on any numerical study in the scalar-tensor scenario. We also demonstrate that the Brans-Dicke theory with an infinite constant parameter $\omega_{\text{BD}}$ is a counterexample of the equivalence between two conformal frames due to the violation of the viable constraint.
- [69] arXiv:2004.03051 (cross-list from gr-qc) [pdf, other]
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Title: Probing Compactified Extra Dimensions with Gravitational WavesComments: 33 pages, 1 figureSubjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Theory (hep-th)
We study the effect of compact extra dimensions on the gravitational wave luminosity and waveform. We consider a toy model, with a compactified fifth dimension, and matter confined on a brane. We work in the context of five dimensional ($5d$) general relativity, though we do make connections with the corresponding Kaluza-Klein effective $4d$ theory. We show that the luminosity of gravitational waves emitted in $5d$ gravity by a binary with the same characteristics (same masses and separation distance) as a $4d$ binary is 20.8\% less relative to the $4d$ case, to leading post-Newtonian order. The phase of the gravitational waveform differs by 26\% relative to the $4d$ case, to leading post-Newtonian order. Such a correction arises mainly due to the coupling between matter and dilaton field in the effective $4d$ picture and agrees with previous calculations when we set black holes' scalar charges to be those computed from the Kaluza-Klein reduction. The above correction is inconsistent with the recent gravitational-wave observations and it thus effectively rules out the possibility of such a simple compactified higher dimensions scenario. We also comment on how our results change if there are several compactified extra dimensions, and show that the discrepancy with $4d$ general relativity only increases.
- [70] arXiv:2004.03410 (cross-list from hep-ph) [pdf, other]
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Title: Gravitational misalignment mechanism of Dark Matter productionComments: 18 pages, 3 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)
We consider Dark Matter composed of an oscillating singlet scalar field. On top of the mass term, the scalar is equipped with a potential spontaneously breaking Z_2-symmetry. This potential dominates at early times and leads to the time-dependent expectation value of the scalar, which decreases in the expanding Universe. As it drops below some critical value, the symmetry gets restored, and the Dark Matter field starts to oscillate around zero. We arrange the spontaneous symmetry breaking through the interaction of the scalar with the Ricci curvature. In that way, superheavy Dark Matter can be produced at very early times. Depending on its mass, the production takes place at inflation (very large masses up to the Grand Unification scale), at preheating, or at radiation-dominated stage (masses 10^{6}-10^{7} Gev).
- [71] arXiv:2004.03463 (cross-list from physics.ins-det) [pdf, other]
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Title: The COSINE-100 Liquid Scintillator Veto SystemAuthors: G. Adhikari, E. Barbosa de Souza, N. Carlin, J. J. Choi, S. Choi, M. Djamal, A. C. Ezeribe, L. E. Franca, C. Ha, I. S. Hahn, E. J. Jeon, J. H. Jo, W. G. Kang, M. Kauer, H. Kim, H. J. Kim, K. W. Kim, S. K. Kim, Y. D. Kim, Y. H. Kim, Y. J. Ko, E. K. Lee, H. S. Lee, J. Lee, J. Y. Lee, M. H. Lee, S. H. Lee, D. S. Leonard, B. B. Manzato, R. H. Maruyama, R. J. Neal, S. L. Olsen, B. J. Park, H. K. Park, H. S. Park, K. S. Park, R. L. C. Pitta, H. Prihtiadi, S. J. Ra, C. Rott, K. A. Shin, A. Scarff, N. J. C. Spooner, W. G. Thompson, L. Yang, G. H. YuSubjects: Instrumentation and Detectors (physics.ins-det); Instrumentation and Methods for Astrophysics (astro-ph.IM); High Energy Physics - Experiment (hep-ex)
This paper describes the liquid scintillator veto system for the COSINE-100 dark matter experiment and its performance. The COSINE-100 detector consists of 8 NaI(Tl) crystals immersed in 2,200~L of linear alkylbenzene based liquid scintillator. The liquid scintillator tags between 65 and 75\% of the internal $^{40}$K background in the 2--6~keV energy region. We also describe the background model for the liquid scintillator, which is primarily used to assess its energy calibration and threshold.
- [72] arXiv:2004.03518 (cross-list from physics.plasm-ph) [pdf, ps, other]
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Title: The two-time energy spectrum of weak magnetohydrodynamic turbulenceComments: Accepted for publication in Physical Review ResearchSubjects: Plasma Physics (physics.plasm-ph); Solar and Stellar Astrophysics (astro-ph.SR); Atmospheric and Oceanic Physics (physics.ao-ph); Fluid Dynamics (physics.flu-dyn); Space Physics (physics.space-ph)
In this work a weak-turbulence closure is used for the first time to determine the structure of the two-time power spectrum of weak magnetohydrodynamic (MHD) turbulence from the nonlinear equations describing the dynamics. The two-time energy spectrum is a fundamental quantity in turbulence theory from which most statistical properties of a homogeneous turbulent system can be derived. A closely related quantity, obtained via a spatial Fourier transform, is the two-point, two-time correlation function describing the space-time correlations arising from the underlying dynamics of the turbulent fluctuations. Both quantities are central in fundamental turbulence theories as well as in the analysis of turbulence experiments and simulations. However, a first-principle derivation of these quantities has remained elusive due to the statistical closure problem, in which dynamical equations for correlations at order $n$ depend on correlations of order $n+1$. The recent launch of the \emph{Parker Solar Probe} (PSP), which will explore the near-Sun region where the solar wind is born, has renewed the interest in the scientific community to understand the structure, and possible universal properties of space-time correlations. The weak MHD turbulence regime that we consider in this work allows for a natural asymptotic closure of the two-time spectrum, which may be applicable to other weak turbulence regimes found in fluids and plasmas. An integro-differential equation for the scale-dependent temporal correlation function is derived for incompressible Alfv\'enic fluctuations whose nonlinear dynamics is described by the Reduced MHD equations.
Replacements for Wed, 8 Apr 20
- [73] arXiv:1809.02905 (replaced) [pdf, other]
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Title: Spectrum of cosmological correlation from vacuum fluctuation of Stringy Axion in entangled De Sitter spaceComments: 73 pages, 13 figures, 1 table, Revised and updated versionSubjects: High Energy Physics - Theory (hep-th); Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph); Quantum Physics (quant-ph)
- [74] arXiv:1905.06966 (replaced) [pdf, other]
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Title: Magnetogenesis from a rotating scalar: à la scalar chiral magnetic effectComments: 35 pages, 1 figure; v2: extended discussions, comments and references added, matches version accepted for publication in JHEPSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)
- [75] arXiv:1906.03493 (replaced) [pdf, other]
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Title: The late-time afterglow evolution of long gamma-ray bursts GRB 160625B and GRB 160509AAuthors: Tuomas Kangas, Andrew S. Fruchter, S. Bradley Cenko, Alessandra Corsi, Antonio de Ugarte Postigo, Asaf Pe'er, Stuart N. Vogel, Antonino Cucchiara, Benjamin Gompertz, John Graham, Andrew Levan, Kuntal Misra, Daniel A. Perley, Judith Racusin, Nial TanvirComments: 19 pages, 9 figures. Revised version; accepted for publication in ApJSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
- [76] arXiv:1906.11248 (replaced) [pdf, other]
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Title: Morpheus: A Deep Learning Framework For Pixel-Level Analysis of Astronomical Image DataComments: 47 pages, 33 figures. Version accepted by ApJS. More information about Morpheus is available at this https URLSubjects: Astrophysics of Galaxies (astro-ph.GA); Machine Learning (cs.LG)
- [77] arXiv:1907.04356 (replaced) [pdf, other]
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Title: Monte-Carlo simulations of black hole mergers in AGN disks: Low $χ_{\rm eff}$ mergers and predictions for LIGOComments: 14 pages, 15 Figs., MNRAS acceptedSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); Astrophysics of Galaxies (astro-ph.GA)
- [78] arXiv:1907.06654 (replaced) [pdf, other]
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Title: Scaling relations and baryonic cycling in local star-forming galaxies: I. The sampleComments: 21 pages, 12 figures. Accepted for publication in A&A. Sample and results improved compared to previous versions. Some analysis has been removed and will be expanded in future papersSubjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [79] arXiv:1908.08775 (replaced) [pdf, other]
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Title: Synthetic catalog of black holes in the Milky WayComments: 21 pages, A&A accepted, data from catalog available onlineSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA); High Energy Astrophysical Phenomena (astro-ph.HE)
- [80] arXiv:1909.03138 (replaced) [pdf, other]
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Title: The Impact of Type Ia Supernovae in Quiescent Galaxies: I. Formation of the Multiphase Interstellar mediumComments: 15 pages, 11 figures, accepted by ApJSubjects: Astrophysics of Galaxies (astro-ph.GA); High Energy Astrophysical Phenomena (astro-ph.HE)
- [81] arXiv:1909.04096 (replaced) [pdf, other]
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Title: Searching for exotic cores with binary neutron star inspiralsComments: ApJL accepted versionJournal-ref: The Astrophysical Journal Letters, Volume 893, Number 1, L4, 2020Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc); Nuclear Theory (nucl-th)
- [82] arXiv:1910.06578 (replaced) [pdf, other]
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Title: High-energy neutrinos from fallback accretion of binary neutron star merger remnantsComments: 29 pages, 8 figuresSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
- [83] arXiv:1910.08124 (replaced) [pdf, other]
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Title: Dark-ages reionization and galaxy formation simulation -- XVIII. The high-redshift evolution of black holes and their host galaxiesComments: 14 pages, 11 figures. Accepted for publication in MNRASSubjects: Astrophysics of Galaxies (astro-ph.GA)
- [84] arXiv:1910.09925 (replaced) [pdf, other]
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Title: Neutron stars: new constraints on asymmetric dark matterComments: 8 pages, 4 figuresSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc)
- [85] arXiv:1910.12682 (replaced) [pdf, other]
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Title: Observability of the innermost stable circular orbit in a near-extremal Kerr black holeComments: 17 pages, 6 figures; v2: published version in PRDJournal-ref: Phys. Rev. D 101, 044044 (2020)Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)
- [86] arXiv:1911.08472 (replaced) [pdf, other]
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Title: Axion FragmentationComments: 29 pages and 17 figures in main text, 24 pages and 7 figures in appendices, v2: published versionSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)
- [87] arXiv:1911.08499 (replaced) [pdf, other]
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Title: Lowly polarized light from a highly magnetized jet of GRB 190114CAuthors: N. Jordana-Mitjans, C. G. Mundell, S. Kobayashi, R. J. Smith, C. Guidorzi, I. A. Steele, M. Shrestha, A. Gomboc, M. Marongiu, R. Martone, V. Lipunov, E. S. Gorbovskoy, D. A. H. Buckley, R. Rebolo, N. M. BudnevComments: The full photometry data is available in the journal publicationJournal-ref: ApJ, 892, 2 (2020)Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)
- [88] arXiv:1911.12083 (replaced) [pdf, other]
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Title: The Mystery of Photometric Twins DES17X1boj and DES16E2bjyAuthors: M. Pursiainen, C. Gutierrez, P. Wiseman, M. Childress, M. Smith, C. Frohmaier, C. Angus, N. Castro Segura, L. Kelsey, M. Sullivan, L. Galbany, P. Nugent, B. A. Bassett, D. Brout, D. Carollo, C. B. D'Andrea, T. M. Davis, R. J. Foley, M. Grayling, S. R. Hinton, C. Inserra, R. Kessler, C. Lidman, E. Macaulay, M. March, A. Moöller, T. Müller, D. Scolnic, N. E. Sommer, E. Swann, B. P. Thomas, B. E. Tucker, M. Vincenzi, T. M. C. Abbott, S. Allam, J. Annis, S. Avila, E. Bertin, D. Brooks, E. Buckley-Geer, D. L. Burke, A. Carnero Rosell, M. Carrasco Kind, L. N. da Costa, J. De Vicente, S. Desai, H. T. Diehl, P. Doel, T. F. Eifler, S. Everett, B. Flaugher, J. Frieman, J. García-Bellido, E. Gaztanaga, D. W. Gerdes, D. Gruen, R. A. Gruendl, J. Gschwend, G. Gutierrez, D. L. Hollowood, et al. (23 additional authors not shown)Comments: Accepted to MNRASSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
- [89] arXiv:1912.11916 (replaced) [pdf, other]
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Title: Strong and weak lensing of Gravitational Waves: a semi-analytical approachComments: 37 pages, 19 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc)
- [90] arXiv:2001.00205 (replaced) [pdf, ps, other]
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Title: Gravitational wave memory from a propagating relativistic jet: a probe to the interior of gamma-ray burst progenitorsAuthors: Yun-Wei YuComments: 6 pages, 4 figuresSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
- [91] arXiv:2001.01761 (replaced) [pdf]
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Title: GW190425: Observation of a Compact Binary Coalescence with Total Mass $\sim 3.4 M_{\odot}$Authors: The LIGO Scientific Collaboration, the Virgo Collaboration: B. P. Abbott, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, K. Ackley, C. Adams, R. X. Adhikari, V. B. Adya, C. Affeldt, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, L. Aiello, A. Ain, P. Ajith, G. Allen, A. Allocca, M. A. Aloy, P. A. Altin, A. Amato, S. Anand, A. Ananyeva, S. B. Anderson, W. G. Anderson, S. V. Angelova, S. Antier, S. Appert, K. Arai, M. C. Araya, J. S. Areeda, M. Arène, N. Arnaud, S. M. Aronson, K. G. Arun, S. Ascenzi, G. Ashton, S. M. Aston, P. Astone, F. Aubin, P. Aufmuth, K. AultONeal, C. Austin, V. Avendano, A. Avila-Alvarez, S. Babak, P. Bacon, F. Badaracco, M. K. M. Bader, S. Bae, J. Baird, P. T. Baker, F. Baldaccini, G. Ballardin, S. W. Ballmer, A. Bals, S. Banagiri, J. C. Barayoga, C. Barbieri, et al. (1140 additional authors not shown)Comments: 24 pages, 19 figures, published in ApJLJournal-ref: Astrophysical Journal Letters 892 (2020) L3Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc)
- [92] arXiv:2001.02780 (replaced) [pdf, other]
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Title: Large Scale Structure Reconstruction with Short-Wavelength ModesComments: 4 pages, 4 figuresJournal-ref: Phys. Rev. D 101, 083510 (2020)Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [93] arXiv:2001.07968 (replaced) [pdf, other]
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Title: GRAMSES: a new route to general relativistic $N$-body simulations in cosmology. Part II. Initial conditionsComments: 27 pages, 4 figures. Major revisions of the Newtonian-relativistic correspondence, main results unchanged. Matches accepted versionSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc)
- [94] arXiv:2001.10792 (replaced) [pdf, other]
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Title: Cosmological constraints from line intensity mapping with interlopersComments: 13 pages, 9 figures. Accepted for publication in ApJSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [95] arXiv:2002.04107 (replaced) [pdf, other]
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Title: Lyman-$α$ Polarization Intensity MappingComments: Phys. Rev. D, accepted version. Main plots: figs. 3, 8, 9Subjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [96] arXiv:2002.08297 (replaced) [pdf, other]
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Title: A Binary Comb Model for Periodic Fast Radio BurstsComments: 8 pages, 2 figures, accepted for publication in ApJ LetterSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR)
- [97] arXiv:2002.11014 (replaced) [pdf, other]
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Title: First discovery of an ultra-cool white dwarf benchmark in common proper motion with an M dwarfAuthors: M. C. Lam, N. C. Hambly, N. Lodieu, S. Blouin, E. J. Harvey, R. J. Smith, M. C. Galvez-Ortiz, Z. H. ZhangComments: 11 pages, 4 figures, 5 tables. Some typographical changesJournal-ref: Monthly Notices of the Royal Astronomical Society, Volume 493, Issue 4, April 2020, Pages 6001-6010Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA)
- [98] arXiv:2003.00523 (replaced) [pdf, ps, other]
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Title: Spectral Signatures of Quasar Ages at z~3Authors: Wei ZhengComments: 22 pages, 10 figures, 3 tablesJournal-ref: The Astrophysical Journal, 892, 139 (2020)Subjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [99] arXiv:2003.01141 (replaced) [pdf, other]
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Title: Resonant capture in quadruple stellar systemsAuthors: Scott TremaineComments: 13 pages, 1 figureJournal-ref: MNRAS 493, 5583-5595 (2020)Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP)
- [100] arXiv:2003.09220 (replaced) [pdf, other]
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Title: On the orbital evolution of meteoroid 2020 CD3, a temporarily captured orbiter of the Earth-Moon systemComments: 6 pages, 4 figures, 2 tables. Revised to match the version published in Monthly Notices of the Royal Astronomical Society. Abstract abridgedJournal-ref: Monthly Notices of the Royal Astronomical Society, 494 (1): 1089-1094 (May 11, 2020)Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
- [101] arXiv:2003.11015 (replaced) [pdf, other]
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Title: Probing angle of birefringence due to long range axion hair from pulsarsComments: 15 pages, 5 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [102] arXiv:2003.12190 (replaced) [pdf, other]
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Title: A broadband X-ray study of a sample of AGNs with [OIII] measured inclinationsComments: 22 pages, 10 figures, accepted to ApJSubjects: Astrophysics of Galaxies (astro-ph.GA); High Energy Astrophysical Phenomena (astro-ph.HE)
- [103] arXiv:2003.13456 (replaced) [pdf, other]
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Title: The Geometry of Isochrone Orbits: from Archimedes' parabolae to Kepler's third lawComments: 54 pages, 18 figuresSubjects: Classical Physics (physics.class-ph); Astrophysics of Galaxies (astro-ph.GA); Mathematical Physics (math-ph)
- [104] arXiv:2004.00617 (replaced) [pdf, other]
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Title: The Likelihood for LSS: Stochasticity of Bias Coefficients at All OrdersComments: 11 pages. v2: very minor change in Eqs. (2.6), (2.8), (2.17), (2.19), (3.16), (3.18), (3.19) to show factorization in real space of the normalization of the likelihood, updated acknowledgementsSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [105] arXiv:2004.01233 (replaced) [pdf, ps, other]
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Title: On variations of $G$ in the geometric scalar theory of gravityAuthors: K.A. BronnikovComments: 7 two-column pages, no figures. A few references addedSubjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)
- [106] arXiv:2004.01662 (replaced) [pdf, other]
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Title: Thin Accretion Disk around a four-dimensional Einstein-Gauss-Bonnet Black HoleComments: 7 pages, 5 figures; V2: references added and some typos are correctedSubjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Theory (hep-th)
- [107] arXiv:2004.01745 (replaced) [pdf, other]
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Title: Solid accretion onto planetary cores in radiative disksComments: 8 pages, 9 figures, accepted for publication on A&ASubjects: Earth and Planetary Astrophysics (astro-ph.EP)
- [108] arXiv:2004.02761 (replaced) [pdf, other]
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Title: Bayesian methods for fitting Baryon Acoustic Oscillations in the Lyman-$α$ forestComments: 18 pages, 4 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [109] arXiv:2004.02775 (replaced) [pdf, ps, other]
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Title: Velocity Response of the Observed Explosive Events in the Lower Solar Atmosphere: I. Formation of the Flowing Cool Loop SystemAuthors: A.K. Srivastava, Yamini K. Rao, P. Konkol, K. Murawski, M. Mathioudakis, Sanjiv K. Tiwari, E. Scullion, J.G. Doyle, B.N. DwivediComments: In Press; The Astrophysical Journal; 14 Pages; 9 FiguresSubjects: Solar and Stellar Astrophysics (astro-ph.SR)
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