Astrophysics
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New submissions for Mon, 17 Feb 20
- [1] arXiv:2002.05720 [pdf, other]
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Title: Episodic accretion constrained by a rich cluster of outflowsAuthors: T. Nony, F. Motte, F. Louvet, A. Plunkett, A. Gusdorf, S. Fechtenbaum, Y. Pouteau, B. Lefloch, S. Bontemps, J. Molet, J.-F. RobitailleComments: Accepted for publication in Astronomy & Astrophysics (23 pages, 15 figures)Subjects: Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)
The accretion history of protostars remains widely mysterious even though it represents one of the best ways to understand the protostellar collapse that leads to the formation of stars. Molecular outflows are here used to characterize the protostellar accretion phase in W43-MM1. The W43-MM1 protocluster host a sufficient number of protostars to statistically investigate molecular outflows in a single, homogeneous region. We used the CO(2-1) and SiO(5-4) line datacubes, taken as part of an ALMA mosaic with a 2000 AU resolution, to search for protostellar outflows, evaluate the influence that the environment has on these outflows' characteristics and put constraints on outflow variability in W43-MM1. We discovered a rich cluster of 46 outflow lobes, driven by 27 protostars with masses of 1-100 Msun. The complex environment inside which these outflow lobes develop has a definite influence on their length, limiting the validity of using outflows' dynamical timescales as a proxy of the ejection timescale in clouds with high dynamics and varying conditions. We performed a detailed study of Position-Velocity (PV) diagrams of outflows that revealed clear events of episodic ejection. The time variability of W43-MM1 outflows is a general trend and is more generally observed than in nearby, low- to intermediate-mass star-forming regions. The typical timescale found between two ejecta, about 500 yr, is consistent with that found in nearby protostars. If ejection episodicity reflects variability in the accretion process, either protostellar accretion is more variable or episodicity is easier to detect in high-mass star-forming regions than in nearby clouds. The timescale found between accretion events could be resulting from disk instabilities, associated with bursts of inflowing gas arising from the dynamical environment of high-mass star-forming cores.
- [2] arXiv:2002.05723 [pdf, other]
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Title: COol Companions ON Ultrawide orbiTS (COCONUTS). I. A High-Gravity T4 Benchmark around an Old White Dwarf and A Re-Examination of the Surface-Gravity Dependence of the L/T TransitionAuthors: Zhoujian Zhang, Michael C. Liu, J. J. Hermes, Eugene A. Magnier, Mark S. Marley, Pier-Emmanuel Tremblay, Michael A. Tucker, Aaron Do, Anna V. Payne, Benjamin J. ShappeeComments: ApJ, in press. 54 pages including 16 figures and 5 tablesSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA)
We present the first discovery from the COol Companions ON Ultrawide orbiTS (COCONUTS) program, a large-scale survey for wide-orbit planetary and substellar companions. We have discovered a co-moving system COCONUTS-1, composed of a hydrogen-dominated white dwarf (PSO J058.9855+45.4184; $d=31.5$ pc) and a T4 companion (PSO J058.9869+45.4296) at a $40.6''$ (1280 au) projected separation. We derive physical properties for COCONUTS-1B from (1) its near-infrared spectrum using cloudless Sonora atmospheric models, and (2) its luminosity and the white dwarf's age ($7.3_{-1.6}^{+2.8}$ Gyr) using Sonora evolutionary models. The two methods give consistent temperatures and radii, but atmospheric models infer a lower surface gravity and therefore an unphysically young age. Assuming evolutionary model parameters ($T_{\rm eff}=1255^{+6}_{-8}$ K, $\log{g}=5.44^{+0.02}_{-0.03}$ dex, $R=0.789^{+0.011}_{-0.005}$ R$_{\rm Jup}$), we find cloudless model atmospheres have brighter Y- and J-band fluxes than the data, suggesting condensate clouds have not fully dispersed around 1300 K. The W2 flux (4.6 $\mu$m) of COCONUTS-1B is fainter than models, suggesting non-equilibrium mixing of CO. To investigate the gravity dependence of the L/T transition, we compile all 60 known L6-T6 benchmarks and derive a homogeneous set of temperatures, surface gravities, and masses. As is well-known, young, low-gravity late-L dwarfs have significantly fainter, redder near-infrared photometry and $\approx200-300$ K cooler temperatures than old, high-gravity objects. Our sample now reveals such gravity dependence becomes weaker for T dwarfs, with young objects having comparable near-infrared photometry and $\approx100$ K cooler temperatures compared to old objects. Finally, we find that young objects have a larger amplitude J-band brightening than old objects, and also brighten at H band as they cross the L/T transition.
- [3] arXiv:2002.05724 [pdf, other]
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Title: Outflows in Star-forming Galaxies: Stacking Analyses of Resolved Winds and the Relation to Their Hosts' PropertiesComments: 20 pages, 11 figures. Accepted for publication in MNRASSubjects: Astrophysics of Galaxies (astro-ph.GA)
Outflows form an integral component in regulating the gas cycling in and out of galaxies, although their impact on the galaxy hosts is still poorly understood. Here we present an analysis of 405 high mass (log M$_{*}$/M$_{\odot}\geqslant10$), star-forming galaxies (excluding AGN) with low inclinations at $z\sim$0, using stacking techniques of the NaD $\lambda\lambda$5889,5895 A neutral gas tracer in IFU observations from the MaNGA DR15 survey. We detect outflows in the central regions of 78/405 galaxies and determine their extent and power through the construction of stacked annuli. We find outflows are most powerful in central regions and extend out to $\sim$1R$_{e}$, with declining mass outflow rates and loading factors as a function of radius. The stacking of spaxels over key galaxy quantities reveals outflow detections in regions of high $\Sigma_{\text{SFR}}$ ($\gtrsim$0.01 M$_{\odot}$yr$^{-1}$kpc$^{-2}$) and $\Sigma_{M_{*}}$ ($\gtrsim$10$^{7}$ M$_{\odot}$kpc$^{-2}$) along the resolved main sequence. Clear correlations with $\Sigma_{\text{SFR}}$ suggest it is the main regulator of outflows, with a critical threshold of $\sim$0.01 M$_{\odot}$yr$^{-1}$kpc$^{-2}$ needed to escape the weight of the disk and launch them. Furthermore, measurements of the H$\delta$ and D$_{n}$4000 indices reveal virtually identical star formation histories between galaxies with outflows and those without. Finally, through stacking of HI 21 cm observations for a subset of our sample, we find outflow galaxies show reduced HI gas fractions at central velocities compared to their non-detection control counterparts, suggestive of some removal of HI gas, likely in the central regions of the galaxies, but not enough to completely quench the host.
- [4] arXiv:2002.05727 [pdf, other]
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Title: Planetary Architectures in Interacting Stellar EnvironmentsComments: Submitted to MNRAS. Comments are welcomeSubjects: Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)
The discovery of Exoplanetary Systems has challenged some of the theories of planet formation, which assume unperturbed evolution of the host star and its planets. However, in star clusters the interactions with flyby stars and binaries may be relatively common during the lifetime of a planetary system. Here, via high-resolution $N$-body simulations of star-planet systems perturbed by interlopers (stars and binaries), we explore the reconfiguration to the planetary system due to the encounters. In particular, via an exploration focused on the strong scattering regime, we derive the fraction of encounters which result in planet ejections, planet transfers and collisions by the interloper star/binary, as a function of the characteristics of the environment (density, velocity dispersion), and for different masses of the flyby star/binary. We find that binary interlopers can significantly increase the cross section of planet ejections and collisions, while they only slightly change the cross section for planet transfers. Therefore, in environments with high binary fractions, floating planets are expected to be relatively common, while in environments with low binary fractions, where the cross sections of planet ejection and transfer are comparable, the rate of planet exchanges between two stars will be comparable to the rate of production of free-floating planets.
- [5] arXiv:2002.05728 [pdf, other]
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Title: Extended stellar systems in the solar neighborhood. IV. Meingast 1: the most massive stellar stream in the solar neighborhoodComments: submitted to A&A on 28.1.2020Subjects: Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)
Nearby stellar streams carry unique information on the dynamical evolution and disruption of stellar systems in the Galaxy, the mass distribution in the disk, and provide unique targets for planet formation and evolution studies. We revisit the stream discovered in Meingast et al (2019) to search for new members, using Gaia DR2 data and a machine learning approach. We use a bagging classifier of one-class Support Vector Machines to perform a search in positions and proper motions for new stream members. We use the variable prediction frequency resulting from the multitude of classifiers to estimate a stream membership criterion which we use to select high fidelity sources. We use the HR diagram and the Cartesian velocity distribution as test and validation tools. We find about 2000 stream members with high-fidelity, or about an order of magnitude more than previously known, unveiling the stream's population across the entire stellar mass spectrum, from B-stars to M-stars, including white dwarfs. We find that, apart from being slightly more metal-poor, the HRD of the stream is indistinguishable from that of the Pleiades cluster. For the mass range at which we are mostly complete, $\sim$0.2 M$_\odot$ $ < $ M $ < $ $\sim$4 M$_\odot$, we find a normal IMF, allowing us to estimate the total mass of stream to be about 2000 M$_\odot$, making this relatively young stream by far the most massive known. In addition, we identify several white dwarfs as potential stream members. The nearby Meingast 1 stream, due to its richness, age, and distance, is a new fundamental laboratory for star and planet formation and evolution studies for the poorly studied gravitationally unbound star-formation mode. We also demonstrate that One-Class Support Vector Machines can be effectively used to unveil the full stellar populations of nearby stellar systems with Gaia data.
- [6] arXiv:2002.05729 [pdf, other]
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Title: A Method to Distinguish Quiescent and Dusty Star-forming Galaxies with Machine LearningAuthors: Charles L. Steinhardt, John R. Weaver, Jack Maxfield, Iary Davidzon, Andreas L. Faisst, Dan Masters, Madeline Schemel, Sune ToftComments: ApJ, in pressSubjects: Astrophysics of Galaxies (astro-ph.GA); Instrumentation and Methods for Astrophysics (astro-ph.IM)
Large photometric surveys provide a rich source of observations of quiescent galaxies, including a surprisingly large population at z>1. However, identifying large, but clean, samples of quiescent galaxies has proven difficult because of their near-degeneracy with interlopers such as dusty, star-forming galaxies. We describe a new technique for selecting quiescent galaxies based upon t-distributed stochastic neighbor embedding (t-SNE), an unsupervised machine learning algorithm for dimensionality reduction. This t-SNE selection provides an improvement both over UVJ, removing interlopers which otherwise would pass color selection, and over photometric template fitting, more strongly towards high redshift. Due to the similarity between the colors of high- and low-redshift quiescent galaxies, under our assumptions t-SNE outperforms template fitting in 63% of trials at redshifts where a large training sample already exists. It also may be able to select quiescent galaxies more efficiently at higher redshifts than the training sample.
- [7] arXiv:2002.05731 [pdf, other]
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Title: The MUSE Hubble Ultra Deep Field Survey XIII. Spatially resolved spectral properties of Lyman alpha haloes around star-forming galaxies at z > 3Authors: Floriane Leclercq, Roland Bacon, Anne Verhamme, Thibault Garel, Jérémy Blaizot, Jarle Brinchmann, Sebastiano Cantalupo, Adélaïde Claeyssens, Simon Conseil, Thierry Contini, Takuya Hashimoto, Edmund Christian Herenz, Haruka Kusakabe, Raffaella Anna Marino, Michael Maseda, Jorryt Matthee, Peter Mitchell, Gabriele Pezzuli, Johan Richard, Kasper Borello Schmidt, Lutz WisotzkiComments: 17+4 pages, 12+3 figures, 2+1 tables, accepted for publication in A&ASubjects: Astrophysics of Galaxies (astro-ph.GA)
We present spatially resolved maps of six individually-detected Lyman alpha haloes (LAHs) as well as a first statistical analysis of the Lyman alpha (Lya) spectral signature in the circum-galactic medium of high-redshift star-forming galaxies using MUSE. Our resolved spectroscopic analysis of the LAHs reveals significant intrahalo variations of the Lya line profile. Using a three-dimensional two-component model for the Lya emission, we measure the full width at half maximum (FWHM), the peak velocity shift and the asymmetry of the Lya line in the core and in the halo of 19 galaxies. We find that the Lya line shape is statistically different in the halo compared to the core for ~40% of our galaxies. Similarly to object-by-object based studies and a recent resolved study using lensing, we find a correlation between the peak velocity shift and the width of the Lya line both at the interstellar and circum-galactic scales. While there is a lack of correlation between the spectral properties and the spatial scale lengths of our LAHs, we find a correlation between the width of the line in the LAH and the halo flux fraction. Interestingly, UV bright galaxies show broader, more redshifted and less asymmetric Lya lines in their haloes. The most significant correlation found is for the FWHM of the line and the UV continuum slope of the galaxy, suggesting that the redder galaxies have broader Lya lines. The generally broad and red line shapes found in the halo component suggests that the Lya haloes are powered either by scattering processes through an outflowing medium, fluorescent emission from outflowing cold clumps of gas, or a mix of both. Considering the large diversity of the Lya line profiles observed in our sample and the lack of strong correlation, the interpretation of our results is still broadly open and underlines the need for realistic spatially resolved models of the LAHs.
- [8] arXiv:2002.05733 [pdf, other]
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Title: Inhomogeneous HeII reionization in Hydrodynamic SimulationsComments: 10 pages, 8 figures. Submitted to MNRASSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
The reionization of the second electron of helium shapes the physical state of intergalactic gas at redshifts between 2 < z < 5. Because performing full in situ radiative transfer in hydrodynamic simulations is computationally expensive for large volumes, the physics of HeII reionization is often approximated by a uniform UV background model that does not capture the patchiness of reionization. We have devised a model that implements the thermal effects of HeII reionization-- a way to bypass a full radiative transfer simulation while still realizing the physics of HeII reionization that affects observables such as the Lyman alpha forest. Here we present a publicly-available code that flexibly models inhomogeneous HeII reionization in simulations at a negligible computational cost. Because many of the parameters of HeII reionization are uncertain, our model is customizable from a set of free parameters. We show results from this code in MP-Gadget. We demonstrate the resulting temperature evolution and temperature-density relation of intergalactic gas-- consistent with recent measurements and previous radiative transfer simulations. We show that the impact of HeII reionization gives rise to subtle signatures in the one-dimensional statistics of the Lyman alpha forest at the level of several per cent, in agreement with previous findings. The flexible nature of these simulations are ideal for studies of HeII reionization and future observations of the HeII Lyman alpha forest.
- [9] arXiv:2002.05735 [pdf, other]
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Title: Spacetime Tomography Using The Event Horizon TelescopeAuthors: Paul Tiede, Hung-Yi Pu, Avery E. Broderick, Roman Gold, Mansour Karami, Jorge A. Preciado-LópezComments: Accepted to ApJSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc)
We have now entered the new era of high-resolution imaging astronomy with the beginning of the Event Horizon Telescope (EHT). The EHT can resolve the dynamics of matter in the immediate vicinity around black holes at and below the horizon scale. One of the candidate black holes, Sagittarius A* flares 1\-4 times a day depending on the wavelength. A possible interpretation of these flares could be hotspots generated through magnetic reconnection events in the accretion flow. In this paper, we construct a semi-analytical model for hotspots that include the effects of shearing as a spot moves along the accretion flow. We then explore the ability of the EHT to recover these hotspots. Even including significant systematic uncertainties, such as thermal noise, diffractive scattering, and background emission due to an accretion disk, we were able to recover the hotspots and spacetime structure to sub-percent precision. Moreover, by observing multiple flaring events we show how the EHT could be used to tomographically map spacetime. This provides new avenues for testing relativistic fluid dynamics and general relativity near the event horizon of supermassive black holes.
- [10] arXiv:2002.05736 [pdf, other]
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Title: COSMOGRAIL XIX: Time delays in 18 strongly lensed quasars from 15 years of optical monitoringAuthors: M. Millon, F. Courbin, V. Bonvin, E. Paic, G. Meylan, M. Tewes, D. Sluse, P. Magain, J. H. H. Chan, A. Galan, R. Joseph, C. Lemon, O. Tihhonova, R. I. Anderson, M. Marmier, B. Chazelas, M. Lendl, A. H. M. J. Triaud, A. WyttenbachComments: Submitted to A&A, 31 pages, 8 figures, 3 TablesSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
We present the results of 15 years of monitoring of lensed quasars conducted by the COSMOGRAIL program at the Leonhard Euler 1.2m Swiss Telescope. The decade-long light curves of 23 lensed QSOs are presented for the first time. We complement our data set with other monitoring data available in the literature to measure the time delays in 18 systems, among which 9 reach a relative precision better than 15% for at least one time delay. To achieve this, we develop an automated version of the curve-shifting toolbox PyCS to ensure robust estimation of the time delay in the presence of microlensing while accounting for the errors due to imperfect representation of microlensing. We also reanalyze the previously published time delays of RX J1131$-$1231 and HE 0435$-$1223, adding respectively 6 and 2 new seasons of monitoring and confirming the previous time-delay measurements. When the time delay measurement is possible, we correct the light curves of the lensed images from their time delay and present the difference curves to highlight the microlensing signal contained in the data. This is to date the largest sample of decade-long lens monitoring data, useful to measure $H_0$, to measure the size of quasar accretion disks with microlensing, and to study quasar variability.
- [11] arXiv:2002.05738 [pdf, other]
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Title: Stellar Streams in Chameleon GravityAuthors: A. P. Naik (1), N. W. Evans (1), E. Puchwein (2), H. Zhao (3), A.-C. Davis (4) ( (1) IoA, Cambridge, (2) Potsdam, (3) St Andrews & KICC, (4) DAMTP, Cambridge)Comments: PRD, 22 pages, 14 figuresSubjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
Theories of gravity that incorporate new scalar degrees of freedom typically require screening mechanisms to ensure consistency with Solar System tests. One widely-studied mechanism -- the chameleon -- can lead to violations of the equivalence principle (EP), as screened and unscreened objects fall differently. If the stars are screened but the surrounding dark matter is not, this leads to asymmetry between leading and trailing streams. We provide analytic estimates of the magnitude of this effect for realistic Galactic mass distributions. Using a restricted N-body code, we simulate 4 satellites with a range of masses and orbits, together with a variety of strengths of the fifth force and screening levels of the Milky Way and satellite. The ratio of the cumulative number function of stars in the leading and trailing stream as a function of longitude from the satellite is computable from simulations, measurable from the stellar data and can provide a direct test. We forecast constraints for streams at large Galactocentric distances, using the specific example case of Hu-Sawicki gravity. Streams with apocentres between 100 and 200 kpc provide attainable constraints at the level of $|f_{R0}| = 10^{-7}$. Still more stringent constraints at the level of $10^{-7.5}$ or even $10^{-8}$ are plausible provided the environmental screening of the satellite is accounted for. These would be among the tightest astrophysical constraints to date. We note further signatures of chameleon gravity: (i) the trailing stellar stream may become detached from the dark matter progenitor if all the stars are lost, (ii) in the extreme fifth force regime, striations in the stellar trailing tail may develop, (iii) if the satellite is fully screened, its orbital frequency is lower than that of the associated dark matter, which is preferentially liberated into the leading tidal tail.
- [12] arXiv:2002.05740 [pdf, other]
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Title: The Early Merger that Made the Galaxy's Stellar HaloAuthors: N.W. Evans (IoA, Cambridge)Comments: 8 page text of invited review at IAU Symposium 353 `Galactic dynamics in the era of large surveys' (Eds M. Valluri, J. Sellwood)Subjects: Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)
The last two years have seen widespread acceptance of the idea that the Milky Way halo was largely created in an early (8-10 Gyr ago) and massive ($> 10^{10} M_\odot$) merger. The roots of this idea pre-date the Gaia mission, but the exquisite proper motions available from Gaia have made the hypothesis irresistible. We trace the history of this idea, reviewing the series of papers that led to our current understanding.
- [13] arXiv:2002.05744 [pdf, other]
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Title: SDSS IV MaNGA -- Metallicity and ionisation parameter in local star-forming galaxies from Bayesian fitting to photoionisation modelsAuthors: M. Mingozzi, F. Belfiore, G. Cresci, K. Bundy, M. Bershady, D. Bizyaev, G. Blanc, M. Boquien, N. Drory, H. Fu, R. Maiolino, R. Riffel, A. Schaefer, T. Storchi-Bergmann, E. Telles, C. Tremonti, N. Zakamska, K. ZhangComments: 27 pages, 23 figures, resubmitted to A&ASubjects: Astrophysics of Galaxies (astro-ph.GA)
We measured gas-phase metallicity, ionisation parameter and dust extinction for 1795 representative local star-forming galaxies using integral field spectroscopy from the SDSS-IV MaNGA survey. We self-consistently derive these quantities by comparing observed line fluxes with photoionisation models using a Bayesian framework. We also present the first comprehensive study of the [SIII]$\lambda\lambda$9069,9532 nebular lines, which have long been predicted to be ideal tracers of the ionisation parameter. Unfortunately, we find that current photoionisation models substantially over-predict [SIII] lines intensity, while broadly reproducing other observed optical line ratios. We discuss how to nonetheless make use of the information provided by [SIII] lines by setting a prior on the ionisation parameter. Following this approach, we derive spatially-resolved maps and radial profiles of metallicity and ionisation parameter. The metallicity radial profiles are comparable with previous works, with metallicity declining toward the outer parts and a flattening in the central regions, in agreement with infall models of galaxy formation, that predict that spiral discs build up through accretion of material, which leads to an inside-out growth. On the other hand, ionisation parameter radial profiles are flat for low-mass galaxies, while their slope becomes positive as galaxy mass increases. However, the ionisation parameter maps we obtain are clumpy, especially for low-mass galaxies. Ionisation parameter is tightly correlated with the H$\alpha$ equivalent width [EW(H$\alpha$)], following a nearly universal relation, which we attribute to the change of the spectral shape of ionising sources due to ageing of HII regions. We derive a positive correlation between ionisation parameter and metallicity at fixed EW(H$\alpha$), in disagreement with previous theoretical works expecting an anti-correlation.
- [14] arXiv:2002.05751 [pdf, other]
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Title: The OTELO survey. III. Demography, morphology, IR luminosity and environment of AGN hostsAuthors: Marina Ramón-Pérez, Ángel Bongiovanni, Ana Mará Pérez García, Jordi Cepa, Jakub Nadolny, Irene Pintos-Castro, Maritza A. Lara-López, Emilio J. Alfaro Navarro, Héctor O. Castañeda, Miguel Cerviño, José Antonio de Diego, Mirian Fernández-Lorenzo, Jesús Gallego, J. Jesús González, J. Ignacio González-Serrano, Iván Oteo Gómez, Ricardo Pérez Martínez, Mirjana Pović, Miguel Sánchez-PortalComments: 31 pages, 32 figures. Published in Astronomy \& AstrophysicsJournal-ref: A&A, 631A (2019), 11RSubjects: Astrophysics of Galaxies (astro-ph.GA)
We take advantage of the capabilities of the OTELO survey to select and study the AGN population in the field. We performed an analysis of the properties of these objects, including their demography, morphology, and IR luminosity. Focusing on the population of H$\alpha$ emitters at $z \sim 0.4$, we also aim to study the environments of AGN and non-AGN galaxies at that redshift. We make use of the multiwavelength catalog of objects in the field compiled by the OTELO survey, unique in terms of minimum line flux and equivalent width. The OTELO pseudo-spectra allow the identification of emission lines and the spectral classification of the sources. We obtained a sample of 72 AGNs in the field of OTELO, selected with four different methods in the optical, X-rays, and mid-infrared bands. We find that using X-rays is the most efficient way to select AGNs. An analysis was performed on the AGN population of OTELO in order to characterize its members. At $z \sim 0.4$, we find that up to 26\% of our H$\alpha$ emitters are AGNs. At that redshift, AGNs are found in identical environments to non-AGNs, although they represent the most clustered group when compared to passive and star-forming galaxies. The majority of our AGNs at any redshift were classified as late-type galaxies, including a 16\% proportion of irregulars. Another 16\% of AGNs show signs of interactions or mergers. Regarding the infrared luminosity, we are able to recover all the luminous infrared galaxies (LIRGs) in the field of OTELO up to $z\sim 1.6$. We find that the proportion of LIRGs and ultra-luminous infrared galaxies (ULIRGs) is higher among the AGN population, and that ULIRGs show a higher fraction of AGNs than LIRGs.
- [15] arXiv:2002.05752 [pdf, other]
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Title: Periodic Fast Radio Bursts with Neutron Star Free/Radiative PrecessionComments: 7 pages, 6 figures, submitted to ApJLSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
The CHIME/FRB collaboration recently reported the detection of a 16 day periodicity in the arrival times of radio bursts from FRB 180916.J0158+65. We study the possibility that the observed periodicity arises from free precession of a magnetized neutron star, and put constraints on different components of the star's magnetic fields. Using a simple geometric model, where radio bursts are emitted from the rotating magnetosphere of a precessing magnetar, we show that the emission pattern as a function of time can match that observed from FRB 180916.J0158+65.
- [16] arXiv:2002.05756 [pdf, other]
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Title: Planet formation: key mechanisms and global modelsComments: To appear in Lecture Notes of the 3rd Advanced School on Exoplanetary Science (Editors Mancini, Biazzo, Bozza, Sozzetti). 100 pages, 27 FigsSubjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
Models of planet formation are built on underlying physical processes. In order to make sense of the origin of the planets we must first understand the origin of their building blocks. This review comes in two parts. The first part presents a detailed description of six key mechanisms of planet formation: 1) The structure and evolution of protoplanetary disks 2) The formation of planetesimals 3) Accretion of protoplanets 4) Orbital migration of growing planets 5) Gas accretion and giant planet migration 6) Resonance trapping during planet migration. While this is not a comprehensive list, it includes processes for which our understanding has changed in recent years or for which key uncertainties remain.
The second part of this review shows how global models are built out of planet formation processes. We present global models to explain different populations of known planetary systems, including close-in small/low-mass planets (i.e., super-Earths), giant exoplanets, and the Solar System's planets. We discuss the different sources of water on rocky exoplanets, and use cosmochemical measurements to constrain the origin of Earth's water. We point out the successes and failings of different models and how they may be falsified.
Finally, we lay out a path for the future trajectory of planet formation studies. - [17] arXiv:2002.05762 [pdf, ps, other]
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Title: Understanding Physical Properties of Young M-dwarfs: NIR spectroscopic studiesAuthors: Dhrimadri Khata (1), Soumen Mondal (1), Ramkrishna Das (1), Supriyo Ghosh (1 and 2) Samrat Ghosh (1) ((1) Satyendra Nath Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata-700 106, (2) Tata Institute of Fundamental Research, Mumbai 400005, India)Comments: 19 pages, 12 figures, accepted on February 08, 2020 for publication in Monthly Notices of the Royal Astronomical Society (MNRAS)Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
We present here medium resolution (\lambda /\Delta\lambda\sim1200) H- and K-band spectra of M type dwarf stars covering the wavelength range 1.50 - 1.80 {\mu}m and 1.95 - 2.45 {\mu}m. The sample includes 53 dwarf stars (M0V-M7V) from new observations using the TIFR Near-Infrared Spectrometer and Imager (TIRSPEC) instrument on the 2-m Himalayan Chandra Telescope (HCT). Using interferometrically-measured effective temperature (T_{eff}), radius and luminosity of nearby bright calibrator stars, we have created new empirical relationships among those fundamental parameters and spectral indices. The equivalent widths of H-band spectral features like Mg (1.57 {\mu}m), Al (1.67 {\mu}m) and Mg (1.71 {\mu}m), and the H_{2}O-H index are found to be good indicators of T_{eff}, radius and luminosity and we establish the linear functions using these features relating to those stellar parameters. The root mean squared error (RMSE) of our best fits are 102K, 0.027R_{\sun} and 0.12dex respectively. Using spectral type standards along with known parallaxes, we calibrate both H and K-band H_{2}O indices as a tracer of spectral type and absolute K_{s} magnitude. Metallicities of M-dwarf samples are estimated using the K-band calibration relationships. The mass of M-dwarfs could be determined using the luminosity (L/L_{\sun}) and we establish a new empirical relation for this. We also compare and contrast our results with other similar work from the literature.
- [18] arXiv:2002.05764 [pdf, other]
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Title: The origin of tail-like structures around protoplanetary disksAuthors: E. I. Vorobyov (1,2,3), A. M. Skliarevskii (2), V. G. Elbakyan (2,4), M. Takami (5), H. B. Liu (5), S.-Y. Liu (5), E. Akiyama (6) ((1) University of Vienna, Department of Astrophysics, Vienna, Austria, (2) Research Institute of Physics, Southern Federal University, Roston-on-Don, Russia, (3) Ural Federal University, Ekaterinburg, Russia, (4) Lund Observatory, Department of Astronomy and Theoretical Physics, Lund University, Sweden, (5) Institute of Astronomy and Astrophysics, Academia Sinica, Taipei, Taiwan, R.O.C., (6) Institute for the Advancement of Higher Education, Hokkaido University, Sapporo, Japan)Comments: Accepted for publication in Astronomy & AstrophysicsSubjects: Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)
We study the origin of tail-like structures recently detected around the disk of SU Aurigae and several FU~Orionis-type stars. Dynamic protostellar disks featuring ejections of gaseous clumps and quiescent protoplanetary disks experiencing a close encounter with an intruder star were modeled using the numerical hydrodynamics code FEOSAD. Both the gas and dust dynamics were taken into account, including dust growth and mutual friction between the gas and dust components. Only plane-of-the-disk encounters were considered. Ejected clumps produce a unique type of tail that is characterized by a bow-shock shape. Such tails originate from the supersonic motion of ejected clumps through the dense envelope that often surrounds young gravitationally unstable protostellar disks. The ejected clumps either sit at the head of the tail-like structure or disperse if their mass is insufficient to withstand the head wind of the envelope. On the other hand, close encounters with quiescent protoplanetary disks produce three types of the tail-like structure; we define these as pre-collisional, post-collisional, and spiral tails. These tails can in principle be distinguished from one another by particular features of the gas and dust flow in and around them. We find that the brown-dwarf-mass intruders do not capture circumintruder disks during the encounter, while the subsolar-mass intruders can acquire appreciable circumintruder disks with elevated dust-to-gas ratios, which can ease their observational detection. However, this is true only for prograde collisions; the retrograde intruders fail to collect appreciable amounts of gas or dust from the disk of the target. The predicted mass of dust in the model tail-like structures is higher than what was inferred for similar structures in SU~Aur, FU~Ori, and Z~CMa, making their observational detection feasible. Abridged.
- [19] arXiv:2002.05771 [pdf, other]
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Title: Particle response of antenna-coupled TES arrays: results from SPIDER and the labAuthors: B. Osherson, J.P. Filippini, J. Fu, R.V. Gramillano, R. Gualtieri, E.C. Shaw, P.A.R. Ade, M. Amiri, S.J. Benton, J.J. Bock, J.R. Bond, S.A. Bryan, H.C. Chiang, C.R. Contaldi, O. Dore, A.A. Fraisse, A.E. Gambrel, N.N. Gandilo, J.E. Gudmundsson, M. Halpern, J. Hartley, M. Hasselfield, G. Hilton, W. Holmes, V.V. Hristov, K.D. Irwin, W.C. Jones, Z.D. Kermish, P.V. Mason, K. Megerian, L. Moncelsi, T.A. Morford, J.M. Nagy, C.B. Netterfield, I.L. Padilla, A.S. Rahlin, C. Reintsema, J.E. Ruhl, M.C. Runyan, J.A. Shariff, J.D. Soler, A. Trangsrud, C. Tucker, R.S. Tucker, A.D. Turner, A.C. Weber, D.V. Wiebe, E.Y. YoungComments: 9 pages, 6 figures, Proceedings of the 18th International Workshop on Low Temperature DetectorsSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Instrumentation and Detectors (physics.ins-det)
Future mm-wave and sub-mm space missions will employ large arrays of multiplexed Transition Edge Sensor (TES) bolometers. Such instruments must contend with the high flux of cosmic rays beyond our atmosphere that induce "glitches" in bolometer data, which posed a challenge to data analysis from the Planck bolometers. Future instruments will face the additional challenges of shared substrate wafers and multiplexed readout wiring. In this work we explore the susceptibility of modern TES arrays to the cosmic ray environment of space using two data sets: the 2015 long-duration balloon flight of the SPIDER cosmic microwave background polarimeter, and a laboratory exposure of SPIDER flight hardware to radioactive sources. We find manageable glitch rates and short glitch durations, leading to minimal effect on SPIDER analysis. We constrain energy propagation within the substrate through a study of multi-detector coincidences, and give a preliminary look at pulse shapes in laboratory data.
- [20] arXiv:2002.05776 [pdf, other]
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Title: HATS-47b, HATS-48Ab, HATS-49b and HATS-72b: Four Warm Giant Planets Transiting K DwarfsAuthors: J. D. Hartman (1), Andrés Jordán (2 and 3), D. Bayliss (4), G. Á. Bakos (1 and 5), J. Bento (6), W. Bhatti (1), R. Brahm (7 and 8 and 3), Z. Csubry (1), N. Espinoza (9), Th. Henning (10), L. Mancini (11 and 10 and 12), K. Penev (13), M. Rabus (14 and 15), P. Sarkis (10), V. Suc (8), M. de Val-Borro (16), G. Zhou (17), J. D. Crane (18), S. Shectman (18), J. K. Teske (18), S. X. Wang (18), R. P. Butler (19), J. Lázár (20), I. Papp (20), P. Sári (20), D. R. Anderson (21 and 4), C. Hellier (21), R. G. West (4), K. Barkaoui (22 and 23), F. J. Pozuelos (22 and 24), E. Jehin (24), M. Gillon (22), L. Nielsen (25), M. Lendl (25 and 26), S. Udry (25), George R. Ricker (27), Roland Vanderspek (27), David W. Latham (28), S. Seager (27 and 29 and 30), Joshua N. Winn (1), et al. (6 additional authors not shown)Comments: Accepted for publication in AJ. 32 pages, 14 figures, 7 tablesSubjects: Earth and Planetary Astrophysics (astro-ph.EP)
We report the discovery of four transiting giant planets around K dwarfs. The planets HATS-47b, HATS-48Ab, HATS-49b, and HATS-72b have masses of $0.369_{-0.021}^{+0.031}$ $M_{J}$, $0.243_{-0.030}^{+0.022}$ $M_{J}$, $0.353_{-0.027}^{+0.038}$ $M_{J}$ and $0.1254\pm0.0039$ $M_{J}$, respectively, and radii of $1.117\pm0.014$ $R_{J}$, $0.800\pm0.015$ $R_{J}$, $0.765\pm0.013$ $R_{J}$, and $0.7224\pm0.0032$ $R_{J}$, respectively. The planets orbit close to their host stars with orbital periods of $3.9228$ d, $3.1317$ d, $4.1480$ d and $7.3279$ d, respectively. The hosts are main sequence K dwarfs with masses of $0.674_{-0.012}^{+0.016}$ $M_{\odot}$, $0.7279\pm0.0066$ $M_{\odot}$, $0.7133\pm0.0075$ $M_{\odot}$, and $0.7311\pm0.0028$ $M_{\odot}$ and with $V$-band magnitudes of $V = 14.829\pm0.010$, $14.35\pm0.11$, $14.998\pm0.040$ and $12.469\pm0.010$. The Super-Neptune HATS-72b (a.k.a.\ WASP-191b and TOI 294.01) was independently identified as a transiting planet candidate by the HATSouth, WASP and TESS surveys, and we present a combined analysis of all of the data gathered by each of these projects (and their follow-up programs). An exceptionally precise mass is measured for HATS-72b thanks to high-precision radial velocity (RV) measurements obtained with VLT/ESPRESSO, FEROS, HARPS and Magellan/PFS. We also incorporate TESS observations of the warm Saturn-hosting systems HATS-47 (a.k.a. TOI 1073.01), HATS-48A and HATS-49. HATS-47 was independently identified as a candidate by the TESS team, while the other two systems were not previously identified from the TESS data. The RV orbital variations are measured for these systems using Magellan/PFS. HATS-48A has a resolved $5.\!\!^{\prime\prime}4$ neighbor in Gaia~DR2, which is a common-proper-motion binary star companion to HATS-48A with a mass of $0.22$ $M_{\odot}$ and a current projected physical separation of $\sim$1,400 au.
- [21] arXiv:2002.05778 [pdf, other]
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Title: Boltzmann hierarchies for self-interacting warm dark matter scenariosComments: 50 pages, 2 figures and 3 appendices. Prepared for submission to JCAPSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph)
We provide a general framework for self-interacting warm dark matter (WDM) in cosmological perturbations, by deriving from first principles a Boltzmann hierarchy which retains certain independence from a particular interaction Lagrangian. We consider elastic interactions among the massive particles, and obtain a hierarchy which is more general than the ones usually obtained for non-relativistic (as for cold DM) or for ultra-relativistic (as for neutrinos) approximations. The more general momentum-dependent kernel integrals in the Boltzmann collision terms, are explicitly calculated for different field-mediator models, including examples of a scalar field (either massive or massless) or a massive vector field. As an application, we study the evolution of the interaction rate per particle under the relaxation time approximation, and assess when a given self-interaction is relevant in comparison with the Hubble expansion rate. Our framework aims to be a useful starting point to evaluate DM self-interaction effects in the linear power spectrum, necessary to then study its evolution all the way to non-linear stages of structure formation, where certain DM interactions were proven to be relevant.
- [22] arXiv:2002.05806 [pdf, other]
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Title: Mass Outflow of the X-ray Emission Line Gas in NGC 4151Authors: S.B. Kraemer, T. J. Turner, J.D. Couto, D.M. Crenshaw, H.R. Schmitt, M. Revalski, T.C. FischerComments: 19 pages, 12 figures. Accepted for publication in the Monthly Notices of the Royal Astronomical SocietySubjects: Astrophysics of Galaxies (astro-ph.GA)
We have analysed Chandra/High Energy Transmission Gratings spectra of the X-ray emission line gas in the Seyfert galaxy NGC 4151. The zeroth order spectral images show extended H- and He-like O and Ne, up to a distance $r \sim$ 200 pc from the nucleus. Using the 1st order spectra, we measure an average line velocity $\sim -230$ km s$^{-1}$, suggesting significant outflow of X-ray gas. We generated Cloudy photoionisation models to fit the 1st order spectra. We required three emission-line components, with column density, log$N_{H}$, and ionisation parameter, log$U$, of 22.5/1.0, 22.5/0.19, and 23.0/-0.50, respectively. To estimate the total mass of ionised gas and the mass outflow rates, we applied the model parameters to fit the zeroth order emission-line profiles of Ne~IX and Ne~X. We determined the total mass of $\approx 5.4 \times$ 10$^{5}$ M_sun. Assuming the same kinematic profile as that for the [O~III] gas, the peak X-ray mass outflow rate was $\approx 1.8$ M_sun yr$^{-1}$, at $r \sim 150$ pc. The total mass and mass outflow rates are similar to those determined using [O~III], implying that the X-ray gas is a major outflow component. However, unlike the optical outflows, the X-ray outflow rate does not drop off at $r >$ 100 pc, which suggests that it may have a greater impact on the host galaxy.
- [23] arXiv:2002.05821 [pdf, ps, other]
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Title: Current and future development of the photoionization code CloudyAuthors: P. A. M. van Hoof (1), G. C. Van de Steene (1), F. Guzmán (2), M. Dehghanian (2), M. Chatzikos (2), G. J. Ferland (2) ((1) Royal Observatory of Belgium, (2) Dept. of Physics and Astronomy, The University of Kentucky)Comments: 12 pages, 5 figures. This paper was presented as an invited lecture at the 12th Serbian Conference on Spectral Line Shapes in Astrophysics in Vrdnik, SerbiaJournal-ref: Contributions of the Astronomical Observatory Skalnat\'e Pleso, 2020, vol. 50, pp 32-43Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA); Instrumentation and Methods for Astrophysics (astro-ph.IM)
The gas that is present in the interstellar medium is usually very far removed from (local) thermodynamic equilibrium, and in some cases may also not be in a steady-state equilibrium with its surroundings. The physics of this material is complex and one needs a sophisticated numerical code to study it. For this purpose the open-source photoionization code Cloudy was created. It models the physical state of the gas and predicts the spectrum that it emits.
Cloudy is continually being developed to improve the treatment of the microphysical processes and the database of fundamental data that it uses. In this paper we will discuss how we are developing the code to improve our high-density predictions by implementing better collisional-radiative models for all ions. We will also briefly discuss the experimental mode in Cloudy to model gas that is not in steady-state equilibrium and present a preliminary model of recombining gas in a planetary nebula that is on the cooling track. We finish with a short discussion of how we are speeding up the code by using parallelization. - [24] arXiv:2002.05823 [pdf, other]
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Title: Molecular jets from low-mass young protostellar objectsAuthors: C.-F. LeeComments: 38 pages, 15 figuresSubjects: Astrophysics of Galaxies (astro-ph.GA)
Molecular jets are seen coming from the youngest protostars in the early phase of low-mass star formation. They are detected in CO, SiO, and SO at (sub)millimeter wavelengths down to the innermost regions, where their associated protostars and accretion disks are deeply embedded and where they are launched and collimated. They are not only the fossil records of accretion history of the protostars but also are expected to play an important role in facilitating the accretion process. Studying their physical properties (e.g., mass-loss rate, velocity, rotation, radius, wiggle, molecular content, shock formation, periodical variation, magnetic field, etc) allows us to probe not only the jet launching and collimation, but also the disk accretion and evolution, and potentially binary formation and planetary formation in the disks. Here I review recent exciting results obtained with high-spatial and high-velocity resolution observations of molecular jets in comparison to those obtained in the optical jets in the later phase of star formation. Future observations of molecular jets with a large sample at high spatial and velocity resolution with ALMA are expected to lead to a breakthrough in our understanding of jets from young stars.
- [25] arXiv:2002.05824 [pdf, other]
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Title: xGASS: passive disks do not host unexpectedly large reservoirs of cold atomic hydrogenComments: 6 pages, 3 figures. Accepted for publication in Monthly Notices of the Royal Astronomical Society LettersSubjects: Astrophysics of Galaxies (astro-ph.GA)
We use the extended GALEX Arecibo SDSS Survey (xGASS) to quantify the relationship between atomic hydrogen (HI) reservoir and current star formation rate (SFR) for central disk galaxies. This is primarily motivated by recent claims for the existence, in this sample, of a large population of passive disks harbouring HI reservoirs as large as those observed in main sequence galaxies. Across the stellar mass range 10$^{9}<$M$_{*}$/M$_{\odot}<$10$^{11}$, we practically find no passive ($\gtrsim$2$\sigma$ below the star-forming main sequence) disk galaxies with HI reservoirs comparable to those typical of star-forming systems. Even including HI non detections at their upper limits, passive disks typically have $\geq$0.5 dex less HI than their active counterparts. We show that previous claims are due to the use of aperture-corrected SFR estimates from the MPA/JHU SDSS DR7 catalog, which do not provide a fair representation of the global SFR of HI-rich galaxies with extended star-forming disks. Our findings confirm that the bulk of the passive disk population in the local Universe is HI-poor. These also imply that the reduction of star formation, even in central disk galaxies, has to be accompanied by a reduction in their HI reservoir.
- [26] arXiv:2002.05828 [pdf, other]
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Title: Observing Strategy for the Legacy SurveysAuthors: Kaylan J. Burleigh, Martin Landriau, Arjun Dey, Dustin Lang, David J. Schlegel, Peter E. Nugent, Robert Blum, Joseph R. Findlay, Douglas P. Finkbeiner, David Herrera, Klaus Honscheid, Stéphanie Juneau, Ian McGreer, Aaron M. Meisner, John Moustakas, Adam D. Myers, Anna Patej, Edward F. Schlafly, Francisco Valdes, Alistair R. Walker, Benjamin A. Weaver, Christophe YècheComments: 10 pages, 3 tables and 5 figuresSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)
The Legacy Surveys, a combination of three ground-based imaging surveys, have mapped 16,000 deg$^2$ in three optical bands ($g$, $r$, and $z$) to a depth 1--$2$~mag deeper than the Sloan Digital Sky Survey (SDSS). Our work addresses one of the major challenges of wide-field imaging surveys conducted at ground-based observatories: the varying depth that results from varying observing conditions at Earth-bound sites. To mitigate these effects, two of the Legacy Surveys (the Dark Energy Camera Legacy Survey, or DECaLS; and the Mayall $z$-band Legacy Survey, or MzLS) employed a unique strategy to dynamically adjust the exposure times as rapidly as possible in response to the changing observing conditions. We present the tiling and observing strategies used by these surveys. We demonstrate that the tiling and dynamic observing strategies jointly result in a more uniform-depth survey that has higher efficiency for a given total observing time compared with the traditional approach of using fixed exposure times.
- [27] arXiv:2002.05838 [pdf]
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Title: Planetary Science with Astrophysical Assets: Defining the Core Capabilities of PlatformsAuthors: James Bauer (UMd), Stefanie Milam (GSFC), Gordon Bjoraker (GSFC), Sean Carey (IPAC, Caltech), Doris Daou (NASA HQ), Leigh Fletcher (University of Leicester), Walt Harris (University of Arizona), Paul Hartogh (MPI-SSRG), Christine Hartzell (UMd), Amanda Hendrix (PSI), Carrie Nugent (Olin College), Andy Rivkin (APL, JHU), Timothy Swindle (LPL, U of AZ), Cristina Thomas (NAU), Matthew Tiscareno (SETI Institute), Geronimo Villanueva (GSFC), Scott Wolk (CfA, Harvard)Comments: Small Bodies Assessment Group Committee on Planetary Science with Astrophysical Assets, submitted to The National Academies of Science, Engineering, and Medicine\'s Call to the Astronomy and Astrophysics Community for Science White PapersSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Earth and Planetary Astrophysics (astro-ph.EP)
We seek to compile a uniform set of basic capabilities and needs to maximize the yield of Solar System science with future Astrophysics assets while allowing those assets to achieve their Astrophysics priorities. Within considerations of cost and complexity, inclusion of capabilities that make a particular platform useable to planetary science provide a critical advantage over platforms lacking such capabilities.
- [28] arXiv:2002.05890 [pdf, other]
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Title: Identification of Pre-flare Processes and Their Possible Role in Driving a Large-scale Flux Rope Eruption with Complex M-class Flare in the Active Region NOAA 12371Authors: Prabir K. Mitra (USO/PRL), Bhuwan Joshi (USO/PRL), Avijeet Prasad (University of Alabama, Huntsville)Comments: 31 pages, 14 figures, 1 table. This is a pre-print of an article published in Solar Physics. The final authenticated version is available online at: this https URLSubjects: Solar and Stellar Astrophysics (astro-ph.SR)
In this article, we study the origin of precursor flare activity and investigate its role towards triggering the eruption of a flux rope which resulted into a dual-peak M-class flare (SOL2015-06-21T02:36) in the active region NOAA 12371. The flare evolved in two distinct phases with peak flux levels of M2.1 and M2.6 at an interval of $\approx$54 min. The active region exhibited striking moving magnetic features (MMFs) along with sunspot rotation. Non-linear force free field (NLFFF) modelling of the active region corona reveals a magnetic flux rope along the polarity inversion line in the trailing sunspot group which is observationally manifested by the co-spatial structures of an active region filament and a hot channel identified in the 304 and 94 \AA\ images, respectively, from the Atmospheric Imaging Assembly (AIA). The active region underwent a prolonged phase of flux enhancement followed by a relatively shorter period of flux cancellation prior to the onset of the flare which led to the build up and activation of the flux rope. Extreme ultra-violet (EUV) images reveal localised and structured pre-flare emission, from the region of MMFs, adjacent to the location of the main flare. Our analysis reveals strong, localised regions of photospheric currents of opposite polarities at the precursor location, thereby making the region susceptible to small-scale magnetic reconnection. Precursor reconnection activity from this location most likely induced a slipping reconnetion towards the northern leg of the hot channel which led to the destabilization of the flux rope. The application of magnetic virial theorem suggests that there was an overall growth of magnetic free energy in the active region during the prolonged pre-flare phase which decayed rapidly after the hot channel eruption and its successful transformation into a halo coronal mass ejection (CME).
- [29] arXiv:2002.05892 [pdf, ps, other]
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Title: Evidence for Spin-orbit Alignment in the TRAPPIST-1 SystemAuthors: Teruyuki Hirano, Eric Gaidos, Joshua N. Winn, Fei Dai, Akihiko Fukui, Masayuki Kuzuhara, Takayuki Kotani, Motohide Tamura, Maria Hjorth, Simon Albrecht, Daniel Huber, Emeline Bolmont, Hiroki Harakawa, Klaus Hodapp, Masato Ishizuka, Shane Jacobson, Mihoko Konishi, Tomoyuki Kudo, Takashi Kurokawa, Jun Nishikawa, Masashi Omiya, Takuma Serizawa, Akitoshi Ueda, Lauren M. WeissComments: 9 pages, 3 figures, accepted for publication in ApJ LettersSubjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
In an effort to measure the Rossiter-McLaughlin effect for the TRAPPIST-1 system, we performed high-resolution spectroscopy during transits of planets e, f, and b. The spectra were obtained with the InfraRed Doppler spectrograph on the Subaru 8.2-m telescope, and were supplemented with simultaneous photometry obtained with a 1-m telescope of the Las Cumbres Observatory Global Telescope. By analyzing the anomalous radial velocities, we found the projected stellar obliquity to be $\lambda=1\pm 28$ degrees under the assumption that the three planets have coplanar orbits, although we caution that the radial-velocity data show correlated noise of unknown origin. We also sought evidence for the expected deformations of the stellar absorption lines, and thereby detected the "Doppler shadow" of planet b with a false alarm probability of $1.7\,\%$. The joint analysis of the observed residual cross-correlation map including the three transits gave $\lambda=19_{-15}^{+13}$ degrees. These results indicate that the the TRAPPIST-1 star is not strongly misaligned with the common orbital plane of the planets, although further observations are encouraged to verify this conclusion.
- [30] arXiv:2002.05898 [pdf, other]
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Title: A probabilistic framework for cosmological inference from peculiar velocitiesAuthors: Lawrence DamComments: 19 pages, 4 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); Instrumentation and Methods for Astrophysics (astro-ph.IM)
We present a Bayesian hierarchical framework for an end-to-end analysis of peculiar velocity surveys, which makes explicit the inference problem of constraining cosmological parameters from redshift-independent distance indicators. We demonstrate our method for a Fundamental Plane-based survey. The essence of our approach is to work closely with observables (angular size, surface brightness, redshift, etc), through which we bypass the use of summary statistics by working with the probability distributions. The hierarchical approach improves upon the usual analysis in several ways. In particular, it allows a consistent analysis without having to make prior assumptions about cosmology during the calibration phase. Moreover, calibration uncertainties are automatically accounted for in parameter estimation. Results are presented for a new, fully analytic posterior marginalised over all latent variables, which we expect to allow for more principled analyses in upcoming surveys. A maximum a posteriori estimator is also given for peculiar velocities derived from Fundamental Plane data.
- [31] arXiv:2002.05926 [pdf, other]
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Title: 3D Hydrodynamical Simulations of a Brown Dwarf Accretion by a Main-Sequence Star and its Impact on the Surface Li AbundanceComments: 4 pages, 1 figure, presented in Lithium in the Universe: to Be or not to Be?, Frascati, 2019. To be published in MemSAISubjects: Solar and Stellar Astrophysics (astro-ph.SR); Computational Physics (physics.comp-ph)
Li-depleted (enhanced) stars in the main-sequence (MS) and (or) the RGB, pose a puzzling mystery. Presently, there is still no clear answer to the mechanism(s) that enables such Li depletion (enhancement). One possible explanation comes from the, still controversial, observational evidence of Li underabundances in MS stars hosting planets, and of a positive correlation between the Li abundance and rotational velocity in some RGB stars, which suggests a stellar collision with a planet-like object as a possible solution. In this study we explore this scenario, performing for first time 3D-hydrodynamical simulations of a 0.019 Mo brown dwarf collision with a MS star under different initial conditions. This enables us to gather information about the impact on the physical structure and final Li content in the hosting star.
- [32] arXiv:2002.05938 [pdf, other]
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Title: Discovery and timing of pulsars in the globular cluster M13 with FASTAuthors: Lin Wang, Bo Peng, B. W. Stappers, Kuo Liu, M. J. Keith, A. G. Lyne, Jiguang Lu, Ye-Zhao Yu, Feifei Kou, Jun Yan, Peng Jiang, Chengjin Jin, Di Li, Lei Qian, Qiming Wang, Youling Yue, Haiyan Zhang, Shuxin Zhang, Yan ZhuComments: 12 pages, 9 figures, accepted for publication in ApJSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); Astrophysics of Galaxies (astro-ph.GA)
We report the discovery of a binary millisecond pulsar (namely PSR J1641+3627F or M13F) in the globular cluster M13 (NGC 6205) and timing solutions of M13A to F using observations made with the Five-hundred-metre Aperture Spherical radio Telescope (FAST). PSR J1641+3627F has a spin period of 3.00 ms and an orbital period of 1.4 days. The most likely companion mass is 0.16 M$_{\odot}$. M13A to E all have short spin periods and small period derivatives. We also confirm that the binary millisecond pulsar PSR J1641$+$3627E (also M13E) is a black widow with a companion mass around 0.02 M$_{\odot}$. We find that all the binary systems have low eccentricities compared to those typical for globular cluster pulsars and that they decrease with distance from the cluster core. This is consistent with what is expected as this cluster has a very low encounter rate per binary.
- [33] arXiv:2002.05957 [pdf]
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Title: Xenon Isotopes Identify Large-scale Nucleosynthetic Heterogeneities across the Solar SystemJournal-ref: The Astrophysical Journal, 2020, 889, 68Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Nuclear Theory (nucl-th)
Nucleosynthetic isotopic anomalies in meteorites and planetary objects contribute to our understanding of the formation of the solar system. Isotope systematics of chondrites demonstrate the existence of a physical separation between isotopic reservoirs in the solar system. The isotopic composition of atmospheric xenon (Xe) indicates that its progenitor, U-Xe, is depleted in 134Xe and 136Xe isotopes relative to Solar or Chondritic end-members. This deficit supports the view that nucleosynthetic heterogeneities persisted during the Solar System formation. Measurements of xenon emitted from comet 67P/Churyumov-Gerasimenko (67P) identified a similar, but more extreme, deficit of cometary gas in these isotopes relative to Solar gas. Here we show that the data from 67P demonstrate that two distinct sources contributed xenon isotopes associated with the r-process to the solar system. The h-process contributed at least 29% (2sigmas) of solar system 136Xe. Mixtures of these r-process components and the s-process that match the heavy isotope signature of cometary Xe lead to depletions of the precursor of atmospheric Xe in p-only isotopes. Only the addition of pure p-process Xe to the isotopic mixture brings 124Xe/132Xe and 126Xe/132Xe ratios back to solar-like values. No pure p-process Xe has been detected in solar system material, and variation in p-process Xe isotopes is always correlated with variation in r-process Xe isotopes. In the solar system, p-process incorporation from the interstellar medium happened before incorporation of r-process nuclides or material in the outer edge of the solar system carries a different mixture of presolar sources as have been preserved in parent bodies.
- [34] arXiv:2002.05977 [pdf, other]
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Title: A redshift database towards the Shapley Supercluster regionAuthors: Hernan Quintana, Dominique Proust, Rolando Dünner, Eleazar R. Carrasco, Andreas ReiseneggerSubjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
We present a database and velocity catalogue towards the region of the Shapley Supercluster based on 18,146 measured velocities for 10,719 galaxies in the approximately 300 square degree area between 12h 43mn 00s < R.A. < 14h 17mn 00s and -23{\deg} 30' 00" < Dec < -38{\deg} 30' 00". The data catalogue contains velocities from the literature found until 2015. It also includes 5,084 velocities, corresponding to 4,617 galaxies, observed by us at Las Campanas and CTIO observatories and not reported individually until now. Of these, 2,585 correspond to galaxies with no other previously published velocity measurement before 2015. Every galaxy in the velocity database has been identified with a galaxy extracted from the SuperCOSMOS photometric catalogues. We also provide a combined average velocity catalogue for all 10,719 galaxies with measured velocities, adopting the SuperCOSMOS positions as a homogeneous base. A general magnitude cut-off at R2=18.0 mag was adopted (with exceptions only for some of the new reported velocities). In general terms, we confirm the overall structure of the Shapley Supercluster, as found on earlier papers. However, the more extensive velocity data show finer structure, to be discussed in a future publication.
- [35] arXiv:2002.05984 [pdf, other]
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Title: Fragmentation of star-forming filaments in the X-shape Nebula of the California molecular cloudComments: 9 pages, 9 figures, submitted to A&ASubjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)
We aim to further investigate the fragmentation of star-forming filaments in the X-shape Nebula of the California MC, so as to better understand the exact role of filaments in the early stages of star formation. We applied getsources and getfilaments extraction methods to the multi-wavelength images observed with Herschel. The properties of the filaments and cores were determined from such an analysis. A map of $\rm ^{13}CO (2-1)$ emission from the SMT 10m telescope was also used to constrain the dynamical state of the filaments. We selected 10 filaments with elongation factors $E >4$ and column density contrasts $C>0.5$ from the filamentary network identified with getfilaments. All 10 filaments have roughly the same deconvolved FWHM width, with a median value $0.12\pm 0.03$ pc, independently of their column densities ranging from $< 10^{21}\, {\rm cm}^{-2}$ to $>10^{22}\, {\rm cm}^{-2}$. Two star-forming filaments stand out based on the Herschel data: Filaments~8 and 10 harbor quasi-periodic chains of dense cores with a typical projected core spacing of $\sim$ 0.15 pc. These two filamentary structures have supercritical line masses and are not static. Filament~8 exhibits a prominent transverse velocity gradient, suggesting that it is accreting gas from the parent cloud gas reservoir. The estimated mass accretion rate is $\sim 40\pm10\ M_\odot \ \rm Myr^{-1}\ pc^{-1}$. Filament~10 includes two embedded protostars with outflows and is likely at a later evolutionary stage than filament~8. Our findings support the notion that dense molecular filaments play a crucial role in the star formation process. We suggest that accretion onto the two star-forming filaments, as well as geometrical bending, explains why the observed core spacing along them is significantly shorter than the canonical separation of $\sim \,$4 times the filament width predicted by classical cylinder fragmentation theory.
- [36] arXiv:2002.05992 [pdf, other]
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Title: The bispectrum and 21cm foregrounds during the Epoch of ReionizationComments: 14 pages, 13 figures + 2 appendix figures. Submitted to MNRAS (14th February 2020)Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
Numerous studies have established the theoretical potential of the 21cm bispectrum to boost our understanding of the Epoch of Reionization (EoR), and therefore early generation of stars and galaxies. In this paper we look at the impact of foregrounds and instrumental effects on the 21cm bispectrum and our ability to measure it. Unlike the power spectrum for which (in the absence of instrumental effects) there is a window clear of smooth-spectrum foregrounds in which the 21cm power spectrum may be detectable, there is no such "EoR window" for the bispectrum. Instead, on smaller scales EoR structure modulates that of the foregrounds (FG) to alter the EoR+FG bispectrum from that of the foregrounds in a complex manner. On larger scales the EoR structures are completely swamped by those of the foregrounds, and the EoR+FG bispectrum is entirely dominated by that of the foregrounds. It is therefore unlikely that the bispectrum will be useful in cases where we are observationally restricted to using foreground avoidance techniques. We also find that there is potential for instrumental effects to seriously corrupt the bispectrum, possibly even rendering the bispectrum useless for parameter estimation. On larger scales, foreground removal using GMCA is found to recover the EoR bispectrum to a reasonable level of accuracy (even better than the power spectrum for certain configurations). Further studies are necessary to understand the error and/or bias associated with foreground removal before the 21cm bispectrum can be practically applied in analysis of future data.
- [37] arXiv:2002.06010 [pdf, ps, other]
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Title: Miscellaneous photometric variations in cataclysmic variables: V455 And, SS Cyg, AQ Men, LQ Peg, RW Tri and UX UMaAuthors: Albert BruchJournal-ref: New Astronomy, 78, 101369 (2020)Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
Cataclysmic variables are among the photometrically most unstable stars in the zoo of stellar objects, exhibiting light variations on all time-scales between millennia and seconds. The literature is full of reports on variable phenomena which often require independent confirmation before they can be accepted as established facts. In this contribution I investigate accounts on miscellaneous variable features observed in six cataclysmic variables, drawing for this purpose largely on archival data, most of which have not been investigated in detail in the past, and complementing these data with some new observations. This enabled to confirm and expand upon some hitherto unconfirmed features in the light curves of these star, as well as the rejection of some others, while in still other cases an unambiguous answer to questions arising from previous papers was not possible.
- [38] arXiv:2002.06044 [pdf, other]
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Title: Is there an early Universe solution to the Hubble tension?Comments: 4 pages, 2 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
We consider a low redshift $(z<0.7)$ cosmological dataset comprising megamasers, cosmic chronometers, type Ia SNe and BAO, which we bin according to their redshift. For each bin, we read the value of $H_0$ by fitting directly to the flat $\Lambda$CDM model. Doing so, we find that $H_0$ descends with redshift, allowing one to fit a line with a non-zero slope of statistical significance $2.1 \, \sigma$. Our results are in accord with a similar descending trend reported by the H0LiCOW collaboration. If substantiated going forward, early Universe solutions to the Hubble tension will struggle explaining this trend.
- [39] arXiv:2002.06045 [pdf, ps, other]
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Title: No nitrogen fractionation on 600 au scale in the Sun progenitor analogue OMC-2 FIR4Authors: F. Fontani, G. Quaia, C. Ceccarelli, L. Colzi, C. Favre, C. Kahane, P. Caselli, C. Codella, L. Podio, S. VitiComments: 10 pages, 5 figures, accepted for publication by MNRASSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)
We show the first interferometric maps of the 14N/15N ratio obtained with the Atacama Large Millimeter Array (ALMA) towards the Solar-like forming protocluster OMC-2 FIR4. We observed N2H+, 15NNH+, N15NH+ (1-0), and N2D+ (2-1), from which we derive the isotopic ratios 14N/15N and D/H. The target is one of the closest analogues of the environment in which our Sun may have formed. The ALMA images, having synthesised beam corresponding to ~600 au, show that the emission of the less abundant isotopologues is distributed in several cores of ~10'' (i.e. ~0.02~pc or 4000 au) embedded in a more extended N2H+ emission. Overall, our results indicate that: (1) 14N/15N does not change across the region at core scales, and (2) 14N/15N does not depend on temperature variations. Our findings also suggest that the 14N/15N variations found in pristine Solar System objects are likely not inherited from the protocluster stage, and hence their reason has to be found elsewhere.
- [40] arXiv:2002.06064 [pdf, other]
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Title: Lifting Grains by the Transient Low Pressure in a Martian Dust DevilJournal-ref: Icarus 339 (2020) 113569Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Lifting dust and sand into the thin Martian atmosphere is a challenging problem. Atmospheric pressure excursions within dust devils have been proposed to support lifting. We verify this idea in laboratory experiments. Pressure differences up to a few Pa are applied along particle layers of 50 to 400 $\rm \mu m$. As samples we used glass beads of $\sim$50 $\rm \mu m$ diameter and irregular basalt grains of $\sim$20 $\rm \mu m$ in size. The total ambient pressure of air was set to 600 Pa. Particles are ejected at pressure differences as low as 2.0 $\rm \pm$ 0.8 Pa. In the case of glass beads, the ejected grains returning to the particle bed can trigger new particle ejections as they reduce cohesion and release the tension from other grains. Therefore, few impacting grains might be sufficient to sustain dust lifting in a dust devil at even lower pressure differences. Particle lift requires a very thin, $\sim$100 $\rm \mu m$, low permeability particle layer on top of supporting ground with larger pore space. Assuming this, our experiments support the idea that pressure excursions in Martian dust devils release grains from the ground.
- [41] arXiv:2002.06101 [pdf, other]
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Title: Revisiting the reactivity between HCO and CH$_3$ on interstellar grain surfacesAuthors: J. Enrique-Romero, S. Álvarez-Barcia, F. J. Kolb, A. Rimola, C. Ceccarelli, N. Balucani, J. Meisner, P. Ugliengo, T. Lamberts, J. KästnerComments: Submitted to MNRAS main journal. For associated supporting material refer to the publication in MNRAS. Accepted 2020 February 14. Received 2020 February 14Subjects: Astrophysics of Galaxies (astro-ph.GA); Chemical Physics (physics.chem-ph)
Formation of interstellar complex organic molecules is currently thought to be dominated by the barrierless coupling between radicals on the interstellar icy grain surfaces. Previous standard DFT results on the reactivity between CH$_3$ and HCO on amorphous water surfaces, showed that formation of CH$_4$ + CO by H transfer from HCO to CH$_3$ assisted by water molecules of the ice was the dominant channel. However, the adopted description of the electronic structure of the biradical (i.e., CH$_3$/HCO) system was inadequate (without the broken-symmetry (BS) approach). In this work, we revisit the original results by means of BS-DFT both in gas phase and with one water molecule simulating the role of the ice. Results indicate that adoption of BS-DFT is mandatory to describe properly biradical systems. In the presence of the single water molecule, the water-assisted H transfer exhibits a high energy barrier. In contrast, CH$_3$CHO formation is found to be barrierless. However, direct H transfer from HCO to CH$_3$ to give CO and CH$_4$ presents a very low energy barrier, hence being a potential competitive channel to the radical coupling and indicating, moreover, that the physical insights ofthe original work remain valid.
- [42] arXiv:2002.06104 [pdf, other]
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Title: A Numerical Model for the Multi-wavelength Lightcurves of PSR J0030+0451Comments: 9 pages, 5 figures, submitted to ApJL. Comments welcome!Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)
Recent modeling of Neutron Star Interior Composition Explorer(NICER) observations of the millisecond pulsar PSR J0030+0451 suggests that the magnetic field of the pulsar is non-dipolar. We construct a magnetic field configuration where foot points of the open field lines closely resemble the hotspot configuration from NICER observations. Using this magnetic field as input, we perform force-free simulations of the magnetosphere of PSR J0030+0451, showing the three-dimensional structure of its plasma-filled magnetosphere. Making simple and physically motivated assumptions about the emitting regions, we are able to construct the multi-wavelength lightcurves that qualitatively agree with the corresponding observations. The agreement suggests that multipole magnetic structures are the key to modeling this type of pulsars, and can be used to constrain the magnetic inclination angle and the location of radio emission.
- [43] arXiv:2002.06114 [pdf, ps, other]
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Title: Inference of solar rotation from perturbations of acoustic mode eigenfunctionsComments: 24 pages, 13 figuresJournal-ref: The Astrophysical Journal, 890, 32 (2020)Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
Today's picture of the internal solar rotation rate profile results essentially from helioseismic analyses of frequency splittings of resonant acoustic waves. Here we present another, complementary estimation of the internal solar rotation rate using the perturbation of the shape of the acoustic waves. For this purpose, we extend a global helioseismic approach developed previously for the investigation of the meridional flow \cite{schad11, schad12, schad13} to work on the components of the differential rotation. We discuss the effect of rotation on mode eigenfunctions and thereon based observables. Based on a numerical study using a simulated rotation rate profile we tailor an inversion approach and also consider the case of the presence of an additional meridional flow. This inversion approach is then applied to data from the MDI (Michelson Doppler Imager aboard the Solar Heliospheric Observatory (SoHO)) instrument and the HMI (Helioseismic and Magnetic Imager aboard the Solar Dynamics Observatory (SDO)) instrument. In the end, rotation rate profiles estimated from eigenfunction perturbation and frequency splittings are compared.
The rotation rate profiles from the two different approaches are qualitatively in good agreement, especially for the MDI data. Significant differences are obtained at high latitudes $> 50^{\circ}$ and near the subsurface. The result from HMI data shows larger discrepancies between the different methods. We find that the two global helioseismic approaches provide complementary methods for measuring solar rotation. Comparing the results from different methods may help to reveal systematic influences that affect analyses based on eigenfunction perturbations, like meridional flow measurements. - [44] arXiv:2002.06127 [pdf, other]
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Title: Tensions in the dark: shedding light on Dark Matter-Dark Energy InteractionsComments: 15 pages, 2 figures. Comments welcomeSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)
The emergence of an increasingly strong tension between the Hubble rate inferred from early and late time observations has reinvigorated interest in non-standard scenarios, with the aim of reconciling these measurements. One such model involves interactions between Dark Matter and Dark Energy. Here we consider a specific form of the coupling between these two fluids proportional to the Dark Energy energy density, which has been shown to mitigate the Hubble tension. We complement the work already discussed in several previous analysis and show that, once all relevant cosmological probes are included, the value of the Hubble parameter in this model is $H_0=69.82_{-0.76}^{+0.63}$~km/(s Mpc). Furthermore, we also perform a statistical model comparison, finding a $\Delta\chi^2$ of $-2.15$ with the inclusion of one additional free parameter. In order to fully test this model as a solution to the $H_0$ tension, future missions such as Euclid will prove vital. For this reason, we also forecast the sensitivity of upcoming planned missions to the main parameters affected by these dark sector interactions and show that within the next decade we will be able to conclusively confirm or disprove the validity of this model as a solution to the $H_0$ tension.
- [45] arXiv:2002.06132 [pdf, other]
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Title: A two-fluid model for black-hole accretion flows: particle acceleration and disc structureComments: 34 pages, 9 figuresJournal-ref: MNRAS 465 (2017), 1409-1442Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Astrophysics of Galaxies (astro-ph.GA)
Hot, tenuous advection-dominated accretion flows around black holes are ideal sites for the Fermi acceleration of relativistic particles at standing shock waves in the accretion disc. Previous work has demonstrated that the shock-acceleration process can be efficient enough to power the observed, strong outflows in radio-loud active galaxies such as M87. However, the dynamical effect (back-reaction) on the flow, exerted by the pressure of the relativistic particles, has not been previously considered, and this effect can have a significant influence on the disc structure. We reexamine the problem by developing a new, two-fluid model for the structure of the accretion disc that includes the dynamical effect of the relativistic particle pressure, combined with the pressure of the background (thermal) gas. The new model is analogous to the two-fluid model of cosmic ray acceleration in supernova-driven shock waves. As part of the model, we also develop a new set of shock jump conditions, which are solved along with the hydrodynamic conservation equations to determine the structure of the accretion disc. The solutions include the formation of a mildly relativistic outflow (jet) at the shock radius, driven by the relativistic particles accelerated in the disc. One of our main conclusions is that in the context of the new two-fluid accretion model, global smooth (shock-free) solutions do not exist, and the disc must always contain a standing shock wave, at least in the inviscid case considered here.
- [46] arXiv:2002.06138 [pdf, other]
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Title: A two-fluid model for black-hole accretion flows: Particle acceleration, outflows, and TeV emissionComments: 27 pages, 9 figuresJournal-ref: MNRAS 491 (2020), 4194-4220Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Astrophysics of Galaxies (astro-ph.GA)
The multi-wavelength spectrum observed from M87 extends from radio wavelengths up to TeV gamma-ray energies. The radio through GeV components have been interpreted successfully using SSC models based on misaligned blazar jets, but the origin of the intense TeV emission detected during flares in 2004, 2005, and 2010 remains puzzling. It has been previously suggested that the TeV flares are produced when a relativistic proton jet originating in the core of M87 collides with a molecular cloud (or stellar atmosphere) located less than one parsec from the central black hole. We explore this scenario in detail here using a self-consistent model for the acceleration of relativistic protons in a shocked, two-fluid ADAF accretion disc. The relativistic protons accelerated in the disc escape to power the observed jet outflows. The distribution function for the jet protons is used to compute the TeV emission produced when the jet collides with a cloud or stellar atmosphere. The simulated broadband radiation spectrum includes radio, X-ray, and GeV components generated via synchrotron, as well as TeV emission generated via the production and decay of muons, positrons, and electrons. The self-consistency of the model is verified by computing the relativistic particle pressure using the distribution function, and comparing it with the relativistic particle pressure obtained from the hydrodynamical model. We demonstrate that the model is able to reproduce the multi-wavelength spectrum from M87 observed by VERITAS and HESS during the high-energy flares in 2004, 2005, and 2010.
- [47] arXiv:2002.06158 [pdf, other]
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Title: Characterizing low contrast Galactic open clusters with GAIA DR2Comments: 19 pages, 5 figures. Accept for publication in MNRASSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)
In this study, we characterized 16 objects previously classified as faint or low contrast Galactic open clusters (OCs). We employed parameters associated to the OCs dynamical evolution: core ($r_c$), tidal ($r_t$) and half-mass ($r_{hm}$) radii, age and crossing time ($t_{cr}$). Relations among these parameters were exploited to draw some evolutionary connections. We also included 11 OCs with previous characterizations to provide wider coverage of the parameters space. The investigated sample spans a considerable range in age (log (t/yr) ~7.0 - 9.7) and Galactocentric distance ($R_G$ ~ 6 - 11 kpc). Most of them present solar metallicity. We employed GAIA DR2 astrometry and photometry and selected member stars through a decontamination algorithm which explores the 3D astrometric space ($\mu_{\alpha}$, $\mu_{\delta}$, $\varpi$) to assign membership likelihoods. Previous studies of most of these objects were based mostly on photometric information. All investigated OCs were proved to be real stellar concentrations and relations among their parameters indicate a general disruption scenario in which OCs tend to be more concentrated as they evolve. Internal interactions sucessively drive OCs to develop more dynamically relaxed structures and make them less subject to mass loss due to tidal effects. Tidal radius tends to increase with $R_G$ in accordance with the strength of the Galactic tidal field. Besides, the correlation between the $r_c$ and the dynamical ratio $\tau_{\textrm{dyn}}$ = age/$t_{cr}$ suggests two distinct evolutionary sequences, which may be consequence of different initial formation conditions.
- [48] arXiv:2002.06162 [pdf, other]
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Title: The Breakthrough Listen Search for Intelligent Life: A 3.95-8.00 GHz Search for Radio Technosignatures in the Restricted Earth Transit ZoneAuthors: Sofia Z. Sheikh, Andrew Siemion, J. Emilio Enriquez, Danny C. Price, Howard Isaacson, Matt Lebofsky, Vishal Gajjar, Paul KalasComments: 17 pages, 8 figures, submitted to ApJSubjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)
We report on a search for artificial narrowband signals of 20 stars within the restricted Earth Transit Zone as a part of the ten-year Breakthrough Listen (BL) search for extraterrestrial intelligence. The restricted Earth Transit Zone is the region of the sky from which an observer would see the Earth transit the Sun with an impact parameter of less than 0.5. This region of the sky is geometrically unique, providing a potential way for an extraterrestrial intelligence to discover the Solar System. The targets were nearby (7-143 pc) and the search covered an electromagnetic frequency range of 3.95-8.00 GHz. We used the Robert C. Byrd Green Bank Telescope to perform these observations with the standard BL data recorder. We searched these data for artificial narrowband ($\sim$Hz) signals with Doppler drift rates of $\pm 20$ Hz s$^{-1}$. We found one set of potential candidate signals on the target HIP 109656 which was then found to be consistent with known properties of anthropogenic radio frequency interference. We find no evidence for radio technosignatures from extraterrestrial intelligence in our observations. The observing campaign achieved a minimum detectable flux which would have allowed detections of emissions that were $10^{-3}$ to $0.88$ times as powerful as the signaling capability of the Arecibo radar transmitter, for the nearest and furthest stars respectively. We conclude that at least $8\%$ of the systems in the restricted Earth Transit Zone within 150 pc do not possess the type of transmitters searched in this survey. To our knowledge, this is the first targeted search for extraterrestrial intelligence of the restricted Earth Transit Zone. All data used in this paper are publicly available via the Breakthrough Listen Public Data Archive (this http URL).
- [49] arXiv:2002.06172 [pdf, other]
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Title: Cosmic-ray anisotropies in right ascension measured by the Pierre Auger ObservatoryAuthors: The Pierre Auger Collaboration: A. Aab, P. Abreu, M. Aglietta, I.F.M. Albuquerque, J.M. Albury, I. Allekotte, A. Almela, J. Alvarez Castillo, J. Alvarez-Muñiz, G.A. Anastasi, L. Anchordoqui, B. Andrada, S. Andringa, C. Aramo, P.R. Araújo Ferreira, H. Asorey, P. Assis, G. Avila, A.M. Badescu, A. Bakalova, A. Balaceanu, F. Barbato, R.J. Barreira Luz, K.H. Becker, J.A. Bellido, C. Berat, M.E. Bertaina, X. Bertou, P.L. Biermann, T. Bister, J. Biteau, A. Blanco, J. Blazek, C. Bleve, M. Boháčová, D. Boncioli, C. Bonifazi, L. Bonneau Arbeletche, N. Borodai, A.M. Botti, J. Brack, T. Bretz, F.L. Briechle, P. Buchholz, A. Bueno, S. Buitink, M. Buscemi, K.S. Caballero-Mora, L. Caccianiga, L. Calcagni, A. Cancio, F. Canfora, I. Caracas, J.M. Carceller, R. Caruso, A. Castellina, et al. (319 additional authors not shown)Comments: Accepted by ApJSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
We present measurements of the large-scale cosmic-ray anisotropies in right ascension, using data collected by the surface detector array of the Pierre Auger Observatory over more than 14 years. We determine the equatorial dipole component, $\vec{d}_\perp$, through a Fourier analysis in right ascension that includes weights for each event so as to account for the main detector-induced systematic effects. For the energies at which the trigger efficiency of the array is small, the ``East-West'' method is employed. Besides using the data from the array with detectors separated by 1500 m, we also include data from the smaller but denser sub-array of detectors with 750 m separation, which allows us to extend the analysis down to $\sim 0.03$ EeV. The most significant equatorial dipole amplitude obtained is that in the cumulative bin above 8~EeV, $d_\perp=6.0^{+1.0}_{-0.9}$%, which is inconsistent with isotropy at the 6$\sigma$ level. In the bins below 8 EeV, we obtain 99% CL upper-bounds on $d_\perp$ at the level of 1 to 3 percent. At energies below 1 EeV, even though the amplitudes are not significant, the phases determined in most of the bins are not far from the right ascension of the Galactic center, at $\alpha_{\rm GC}=-94^\circ$, suggesting a predominantly Galactic origin for anisotropies at these energies. The reconstructed dipole phases in the energy bins above 4 EeV point instead to right ascensions that are almost opposite to the Galactic center one, indicative of an extragalactic cosmic ray origin.
Cross-lists for Mon, 17 Feb 20
- [50] arXiv:2002.02463 (cross-list from hep-ph) [pdf, other]
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Title: The top way to relax the Higgs mass and its vacuum energyComments: 14 pages, 3 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)
We consider an ultra-light scalar coupled to the Higgs in the presence of heavier new physics. In the electroweak broken phase the Higgs gives a tree-level contribution to the light-scalar potential, while new physics contributes at loop level. Thereby, the theory has a cosmologically meta-stable phase where the light scalar is around the top of its potential, and the Higgs is a loop factor lighter than new physics. Such regions with precarious naturalness are anthropically and environmentally selected, as regions with heavier Higgs crunch quickly. We expect observable effects of rolling in the dark-energy equation of state. Furthermore, vacuum energies up to the weak scale can be canceled down to anthropically small values.
- [51] arXiv:2002.05862 (cross-list from gr-qc) [pdf, other]
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Title: PPN rotation curves in static distributions with spherical symmetryComments: 15 pages, 6 figuresSubjects: General Relativity and Quantum Cosmology (gr-qc); Astrophysics of Galaxies (astro-ph.GA)
From a Parametrized Post-Newtonian (PPN) [46-51] perspective, we address the question of whether or not the new degrees of freedom, represented by the PPN potentials, can lead to significant modifications in the dynamics of galaxies in the direction of rendering dark matter obsolete. Here, we focus on the study of rotation curves associated with spherically symmetric configurations. The values for the post-Newtonian parameters, which help us to classify the different metric theories of gravity, are tightly constrained mainly by solar system experiments [47,48]. However, in recent years, metric theories characterized by screening mechanisms [4,10,22,25] have become popular, due to the fact that they lead to the possibility of modifications in larger scales than the solar system while retaining the success of GR on it, allowing for violations of the constraints of the Post-Newtonian parameters. In such a context, we consider here two kinds of solutions for field equations: (i) Vacuum solutions and (ii) in the presence of a politropic distribution of matter. For the case (i) we find that the post-Newtonian corrections do not lead to modifications significant enough to be considered an alternative to the dark matter hypothesis. In the case (ii) we find that for a wide range of values for the PPN parameters {\gamma}, {\beta}, {\xi}, {\alpha}_3 , {\zeta}_1 and {\zeta}_2 , the need for dark matter is unavoidable, in order to find flat rotation curves. It is only for theories in which {\zeta}_3>0 that some resemblance of flat rotation curves is found. The latter suggests, at least for the models considered, that these are the only theories capable of replacing dark matter as a possible explanation for the dynamics of galaxies.
- [52] arXiv:2002.05903 (cross-list from gr-qc) [pdf, ps, other]
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Title: No hair for spherically symmetric neutral black holes: nonminimally coupled massive scalar fieldsAuthors: Shahar HodComments: 7 pagesJournal-ref: Physical Review D 96, 124037 (2017)Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Theory (hep-th)
It is proved that spherically symmetric asymptotically flat neutral black holes cannot support spatially regular static configurations made of massive scalar fields with non-minimal coupling to gravity. Interestingly, our compact no-hair theorem is valid for generic values of the dimensionless physical parameter $\xi$ which quantifies the strength of coupling between the scalar field and the spacetime curvature.
- [53] arXiv:2002.06123 (cross-list from hep-ph) [pdf, other]
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Title: Light by Light Scattering as a New Probe for AxionsComments: 13 pages, 3 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); Instrumentation and Methods for Astrophysics (astro-ph.IM); High Energy Physics - Experiment (hep-ex); Optics (physics.optics)
We study the impact of virtual axions on the polarization of photons inside a cavity during the interaction of high-power laser pulses. A novel detection scheme for measuring the axion-induced ellipticity signal during the Light-by-Light (LBL) scattering process is investigated. We show that a momentum exchange between photons in a probe laser beam and a high-intensity target beam may lead to a resonance at the physical mass of the axion. Consequently, the resonant enhancement of vacuum birefringence gives rise to a large ellipticity signal. This signal enhancement can be applied in order to discriminate between the axion contribution to LBL scattering and the standard model contribution due to electron-positron pairs. The sensitivity of the scheme is studied for experimentally feasible probe light sources and ultrahigh intensity laser backgrounds. It is shown that this technique has the potential to probe the QCD axion in the mass range $10^{-2} \textrm{eV} \lesssim m_{a} \lesssim 1 \textrm{eV}$. In this region the axion induced signal surpasses the standard model background.
Replacements for Mon, 17 Feb 20
- [54] arXiv:1702.02586 (replaced) [pdf, other]
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Title: Constraints on the Intergalactic Magnetic Field from Bow Ties in the Gamma-ray SkyAuthors: Paul Tiede, Avery E. Broderick, Mohamad Shalaby, Christoph Pfrommer, Ewald Puchwein, Philip Chang, Astrid LambertsComments: 12 pages, 14 figures, 1 appendix. Accepted to ApJSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [55] arXiv:1801.08402 (replaced) [pdf, other]
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Title: Dynamical System Analysis of a Five-Dimensional Cosmological ModelComments: 14 pages, 2 figures; matches the published versionJournal-ref: Astrophys Space Sci (2018) 363: 215Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [56] arXiv:1809.06907 (replaced) [pdf, other]
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Title: Evaluating the Effect of Four Immeasurable Parameters Included in a Latitudinal Energy Balance Model on the Habitability of ExoplanetsComments: 28 pages, 12 figures , 2 tablesSubjects: Earth and Planetary Astrophysics (astro-ph.EP)
- [57] arXiv:1907.06674 (replaced) [pdf, other]
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Title: Death by Dark MatterComments: 9 pages, 2 figureSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph)
- [58] arXiv:1908.07534 (replaced) [pdf, other]
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Title: A new probe of Axion-Like Particles: CMB polarization distortions due to cluster magnetic fieldsComments: 34 pages, 15 figures. Matches the version accepted for publication in JCAP. Fig. 5 and Fig. 6 are added in the revised versionSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
- [59] arXiv:1909.02239 (replaced) [pdf, other]
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Title: Coronal Synchrotron and Neutrino Emission from the Core of NGC 1068Comments: 7 pages, 2 figures, new ALMA data are added, accepted by ApJLSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
- [60] arXiv:1909.07439 (replaced) [pdf, other]
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Title: Bonsai-SPH: A GPU accelerated astrophysical Smoothed Particle Hydrodynamics codeComments: Updated intro and multi-GPU sections. 23 pages, 9 figures. Submission to SciPostSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Distributed, Parallel, and Cluster Computing (cs.DC); Computational Physics (physics.comp-ph)
- [61] arXiv:1909.11109 (replaced) [pdf, other]
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Title: The Green Bank North Celestial Cap Pulsar Survey. V. Pulsar Census and Survey SensitivityAuthors: Alexander McEwen, Renee Spiewak, Joseph Swiggum, David Kaplan, William Fiore, Gabriella Agazie, Harsha Blumer, Pragya Chawla, Megan DeCesar, Victoria Kaspi, Vladislav Kondratiev, Malcolm LaRose, Lina Levin, Ryan Lynch, Maura McLaughlin, Michael Mingyar, Hind Noori, Scott Ransom, Mallory Roberts, Ann Schmiedekamp, Carl Schmiedecamp, Xavier Siemens, Ingrid Stairs, Kevin Stovall, Mayuresh Surnis, Joeri van LeeuwenSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
- [62] arXiv:1910.02429 (replaced) [pdf, other]
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Title: Gamma-ray and Neutrino Emissions due to Cosmic-Ray Protons Accelerated at Intracluster Shocks in Galaxy ClustersAuthors: Ji-Hoon Ha (1), Dongsu Ryu (1), Hyesung Kang (2) ((1) UNIST, Korea, (2) Pusan National University, Korea)Comments: submitted to ApJ; revised by including reaccelerationSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
- [63] arXiv:1910.11387 (replaced) [pdf, other]
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Title: Proton acceleration in pulsar magnetospheresComments: 14 pages, 12 figures, accepted for publication in A&ASubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
- [64] arXiv:1910.12494 (replaced) [pdf, other]
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Title: Modeling uncertainties in X-ray reflection spectroscopy measurements I: Impact of higher order disk imagesComments: 9 pages, 5 figures. v2: refereed versionJournal-ref: Phys. Rev. D 101, 043010 (2020)Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE)
- [65] arXiv:1910.13762 (replaced) [pdf, other]
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Title: Molecular cloud formation by compression of magnetized turbulent gas subjected to radiative coolingComments: 18 pages, 9 figures. Accepted for publication in MNRASSubjects: Astrophysics of Galaxies (astro-ph.GA)
- [66] arXiv:1911.02618 (replaced) [pdf, other]
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Title: Dark degeneracy I: Dynamical or interacting dark energy?Authors: Rodrigo von Marttens, Lucas Lombriser, Martin Kunz, Valerio Marra, Luciano Casarini, Jailson AlcanizComments: 34 pages, 18 figuresJournal-ref: Physics of the Dark Universe, Volume 28, May 2020, 100490Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc)
- [67] arXiv:1911.06259 (replaced) [pdf, other]
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Title: Restricted Boltzmann Machines for galaxy morphology classification with a quantum annealerComments: 15 pages; LaTeX; 14 figuresSubjects: Quantum Physics (quant-ph); Astrophysics of Galaxies (astro-ph.GA); Machine Learning (cs.LG)
- [68] arXiv:1911.07855 (replaced) [pdf, ps, other]
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Title: Impact of our local environment on cosmological statisticsAuthors: Alex HallComments: 20 pages, 10 figures. Added new Figure 9 showing (mild) dependence on smoothing scale. Minor changes to match version published in Physical Review DSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [69] arXiv:1912.01737 (replaced) [pdf, other]
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Title: Formation of SMBH seeds in Pop III star clusters through collisions : the importance of mass lossComments: 12 pages, 9 figures, accepted by MNRASSubjects: Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)
- [70] arXiv:1912.06340 (replaced) [pdf, other]
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Title: Condition for directly testing scalar modes of gravitational waves by four detectorsComments: 6 pages, 4 figures, 2 tables, adding discussions on a fifth detector (LIGO-India), accepted by PRD (as a Rapid Communication)Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Theory (hep-th)
- [71] arXiv:1912.11543 (replaced) [pdf, other]
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Title: 2 Fast 2 Fiducial: Gaussian processes for the interpolation and marginalization of waveform error in extreme-mass-ratio-inspiral parameter estimationAuthors: Alvin J. K. Chua, Natalia Korsakova, Christopher J. Moore, Jonathan R. Gair, Stanislav BabakComments: Published versionJournal-ref: Phys. Rev. D 101, 044027 (2020)Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc)
- [72] arXiv:2001.03177 (replaced) [pdf, other]
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Title: The Chemical Compositions of Accreted and {\it in situ} Galactic Globular Clusters According to SDSS/APOGEEAuthors: Danny Horta, Ricardo P. Schiavon, J. Ted Mackereth, Timothy C. Beers, José G. Fernández-Trincado, Peter M. Frinchaboy, D.A. García-Hernández, Doug Geisler, Sten Hasselquist, Henrik Jönsson, Richard R. Lane, Steven R. Majewski, Szabolcs Mészáros, Christian Moni Bidin, David M. Nataf, Alexandre Roman-Lopes, Christian Nitschelm, Jaime Vargas-González, Gail ZasowskiComments: 18 pages, 10 figures, 3 tables. Accepted for publication in MNRASSubjects: Astrophysics of Galaxies (astro-ph.GA)
- [73] arXiv:2001.08282 (replaced) [pdf, other]
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Title: Mutual Inclination Excitation by Stellar OblatenessComments: 8 pages, 4 figures, 1 table; accepted for publication in ApJLSubjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
- [74] arXiv:2001.10200 (replaced) [pdf, other]
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Title: The Multivariate Extension of the Lomb-Scargle MethodComments: to be publishedSubjects: Methodology (stat.ME); Instrumentation and Methods for Astrophysics (astro-ph.IM)
- [75] arXiv:2001.11420 (replaced) [pdf, other]
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Title: Hints of dark energy anisotropic stress using Machine LearningComments: 13 pages, 5 figures, 2 tables, comments welcomeSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)
- [76] arXiv:2001.11445 (replaced) [pdf, ps, other]
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Title: IGRINS Slit-Viewing Camera SoftwareAuthors: Hye-In Lee, Soojong Pak, Gregory N. Mace, Kyle F. Kaplan, Huynh Anh N. Le, Heeyoung Oh, Chan Park, Sungho LeeComments: 29 pagesSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)
- [77] arXiv:2002.02197 (replaced) [pdf, ps, other]
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Title: A new orbital ephemeris for WASP-128bComments: Published in Research Notes of the American Astronomical Society (RNAAS)Journal-ref: RNAAS, 4, 23 (2020)Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
- [78] arXiv:2002.02858 (replaced) [pdf, other]
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Title: The VIRUS-P Exploration of Nearby Galaxies (VENGA): The stellar populations and assembly of NGC 2903's bulge, bar, and outer discAuthors: Andreia Carrillo, Shardha Jogee, Niv Drory, Kyle F. Kaplan, Guillermo Blanc, Tim Weinzirl, Mimi Song, Rongxin LuoComments: 14 pages, 9 figures, 2 tables, accepted in MNRAS, added referenceSubjects: Astrophysics of Galaxies (astro-ph.GA)
- [79] arXiv:2002.03011 (replaced) [pdf]
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Title: Probability Distribution of Magnetic Field Strengths through the Cyclotron Lines in High-Mass X-ray BinariesComments: Accepted for publication in Jordan Journal of PhysicSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
- [80] arXiv:2002.03813 (replaced) [pdf, other]
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Title: A 5deg x 5deg deep HI survey of the M81 group: II. HI distribution and kinematics of IC 2574 and HIJASS J1021+68Comments: 15 pages, 17 figures. Accepted for publication in MNRASSubjects: Astrophysics of Galaxies (astro-ph.GA)
- [81] arXiv:2002.04748 (replaced) [pdf, other]
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Title: A Systematic Study of the dust of Galactic Supernova Remnants I. The Distance and the ExtinctionComments: 53 pages, 16 figures; accepted for publication in ApJSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)
- [82] arXiv:2002.04798 (replaced) [pdf, other]
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Title: The TRAPPIST-1 JWST Community InitiativeAuthors: Michaël Gillon, Victoria Meadows, Eric Agol, Adam J. Burgasser, Drake Deming, René Doyon, Jonathan Fortney, Laura Kreidberg, James Owen, Franck Selsis, Julien de Wit, Jacob Lustig-Yaeger, Benjamin V. RackhamComments: Comments and suggestions are welcome and can be addressed to "t1jwstci_board@u.washington.edu". 23 pages, 8 figuresSubjects: Earth and Planetary Astrophysics (astro-ph.EP)
- [83] arXiv:2002.05154 (replaced) [pdf, other]
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Title: Probing the Seesaw Mechanism with Cosmological dataSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)
- [84] arXiv:2002.05415 (replaced) [pdf, ps, other]
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Title: Three discoveries of gamma Cas analogs from dedicated XMM-Newton observations of Be starsAuthors: Yael Naze (U Liege), Christian Motch (U Strasbourg), Gregor Rauw, Shami Kumar (U Liege), Jan Robrade (U Hamburg), Raimundo Lopes de Oliveira (U F Sergipe), Myron A. Smith (NOAO), Jose M. Torrejon (U Alicante)Comments: accepted for publication in MNRASSubjects: Solar and Stellar Astrophysics (astro-ph.SR); High Energy Astrophysical Phenomena (astro-ph.HE)
- [85] arXiv:2002.05480 (replaced) [pdf, other]
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Title: Seeds of Life in Space (SOLIS). VI. Chemical evolution of sulfuretted species along the outflows driven by the low-mass protostellar binary NGC1333-IRAS4AAuthors: Vianney Taquet, Claudio Codella, Marta de Simone, Ana López-Sepulcre, Jaime E. Pineda, Dominique Segura-Cox, Cecilia Ceccarelli, Paola Caselli, Antoine Gusdorf, Magnus V. Persson, the SOLIS teamComments: Accepted for publication in A&ASubjects: Astrophysics of Galaxies (astro-ph.GA)
- [86] arXiv:2002.05622 (replaced) [pdf, other]
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Title: Minimizing the polarization leakage of geometric-phase coronagraphs with multiple grating pattern combinationsComments: 23 pages, 15 figures, accepted for publication in PASPSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)
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