Astrophysics
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New submissions for Fri, 14 Feb 20
- [1] arXiv:2002.05159 [pdf, ps, other]
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Title: Photometric study of close binary stars in the M35, M67, and M71 Galactic clustersComments: 5 pages, 4 figures, accepted for publication in CAOSPSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)
We obtained new multicolour photometry of close binary stars in the young open cluster M35, the solar-age open cluster M67, and the globular cluster M71. New observations have been carried out at the T\"{U}B\.{I}TAK National Observatory (TUG) by using the 100cm (T100) telescope. We present observational results for eclipsing binary systems in the selected Galactic clusters. New accurate light curves for 2MASS J19532554 + 1851175, 2MASS J19533427 + 1844047, 2MASS J06092044 + 2415155, and AH Cnc were obtained. The light curves were analysed and we derived some of the orbital parameters of the systems.
- [2] arXiv:2002.05164 [pdf, other]
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Title: Inner Boundary Condition in Quasi-Lagrangian Simulations of Accretion DisksComments: 10 pages, 5 figures, submitted to AAS journals. Comments welcomeSubjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
In simulations of viscously evolving accretion disks, the inner boundary condition is particularly important. If treated incorrectly, it induces incorrect behavior very quickly, because the viscous time is shortest near the inner boundary. Recent work has determined the correct inner boundary in Eulerian simulations. But in quasi-Lagrangian simulations (e.g., SPH, moving mesh, and mesh-less), where the inner boundary is modeled by removing mass within a finite zone, the inner density profile typically becomes anomalously depleted. Here we show how the boundary condition should be applied in such codes, via a simple modification of the usual approach: when one removes mass, one must speed up the remaining material so that the disk's angular momentum is unchanged. We show with both 1D and 2D moving-mesh (AREPO) simulations that this scheme works as desired in viscously evolving disks. It produces no spurious density depletions and is independent of the mass removal rate. This "torque-free" mass removal technique permits the use of quasi-Lagrangian codes to simulate viscously evolving disks, while including a variety of additional effects. As an example, we apply our scheme to a 2D simulation of an accretion disk perturbed by a very massive planet, in which the disk is evolved to viscous steady state.
- [3] arXiv:2002.05165 [pdf, other]
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Title: Dark Photon Oscillations in Our Inhomogeneous UniverseComments: 5+7 pages, 3+5 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph)
A dark photon may kinetically mix with the ordinary photon, inducing oscillations with observable imprints on cosmology. Oscillations are resonantly enhanced if the dark photon mass equals the ordinary photon plasma mass, which tracks the free electron number density. Previous studies have assumed a homogeneous Universe; in this Letter, we introduce for the first time an analytic formalism for treating resonant oscillations in the presence of inhomogeneities of the photon plasma mass. We apply our formalism to determine constraints from Cosmic Microwave Background photons oscillating into dark photons, and from heating of the primordial plasma due to dark photon dark matter converting into low-energy photons. Including the effect of inhomogeneities demonstrates that prior homogeneous constraints are not conservative, and simultaneously extends current experimental limits into a vast new parameter space.
- [4] arXiv:2002.05168 [pdf, other]
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Title: Mass loss and the Eddington parameter: a new mass-loss recipe for hot and massive starsAuthors: Joachim M. BestenlehnerComments: Accepted for publication in MNRAS, 9 pages, 5 figuresSubjects: Solar and Stellar Astrophysics (astro-ph.SR)
Mass loss through stellar winds plays a dominant role in the evolution of massive stars. In particular the mass-loss rates of very massive stars (VMSs, $> 100\,M_{\odot}$) are highly uncertain. Such stars display Wolf-Rayet spectral morphologies (WNh) whilst on the main-sequence. Metal-poor VMSs are progenitors of gamma-ray bursts and pair instability supernovae. In this study we extended the widely used stellar wind theory by Castor, Abbott & Klein from the optically thin (O star) to the optically thick main-sequence (WNh) wind regime. In particular we modify the mass-loss rate formula in a way that we are able to explain the empirical mass-loss dependence on the Eddington parameter ($\Gamma_{\rm e}$). The new mass-loss recipe is suitable for incorporation into current stellar evolution models for massive and very massive stars. It makes verifiable predictions, namely how the mass-loss rate scales with metallicity and at which Eddington parameter the transition from optically thin O star to optically thick WNh star winds occurs. In the case of the star cluster R136 in the Large Magellanic Cloud we find in the optically thin wind regime $\dot{M} \propto \Gamma_{\rm e}^{3}$ while in the optically thick wind regime $\dot{M} \propto 1/ (1 - \Gamma_{\rm e})^{3.5}$. The transition from optically thin to optically thick winds occurs at $\Gamma_{\rm e, trans} \approx 0.47$. The transition mass-loss rate is $\log \dot{M}~(M_{\odot} \mathrm{yr}^{-1}) \approx -4.76 \pm 0.18$, which is in line with the prediction by Vink & Gr\"afener assuming a volume filling factor of $f_{\rm V} = 0.23_{-0.15}^{+0.40}$.
- [5] arXiv:2002.05171 [pdf, other]
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Title: One hundred SMUDGes in S-PLUS: ultra-diffuse galaxies flourish in the fieldAuthors: C. E. Barbosa, D. Zaritsky, R. Donnerstein, H. Zhang, A. Dey, C. Mendes de Oliveira, L. Sampedro, A. Molino, M. V. Costa-Duarte, P. Coelho, A. Cortesi, F. R. Herpich, J. A. Hernandez-Jimenez, T. Santos-Silva, E. Pereira, A. Werle, R. A. Overzier, R. Cid Fernandes, A. V. Smith Castelli, T. Ribeiro, W. Schoenell, A. KanaanComments: 24 pages, 10 figures, accepted for Publication in ApJSSubjects: Astrophysics of Galaxies (astro-ph.GA)
We present the first systematic study of the stellar populations of ultra-diffuse galaxies (UDGs) in the field, integrating the large area search and characterization of UDGs by the SMUDGes survey with the twelve-band optical photometry of the S-PLUS survey. Based on Bayesian modeling of the optical colors of UDGs, we determine the ages, metallicities and stellar masses of 100 UDGs distributed in an area of $\sim 330$ deg$^2$ in the Stripe 82 region. We find that the stellar masses and metallicities of field UDGs are similar to those observed in clusters and follow the trends previously defined in studies of dwarf and giant galaxies. However, field UDGs have younger luminosity-weighted ages than do UDGs in clusters. We interpret this result to mean that field UDGs have more extended star formation histories, including some that continue to form stars at low levels to the present time. Finally, we examine stellar population scaling relations that show that UDGs are, as a population, similar to other low-surface brightness galaxies.
- [6] arXiv:2002.05172 [pdf, other]
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Title: Impact of magneto-rotational instability on grain growth in protoplanetary disks: I. Relevant turbulence propertiesComments: Accepted by ApJSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP)
Turbulence in the protoplanetary disks induces collisions between dust grains, and thus facilitates grain growth. We investigate the two fundamental assumptions of the turbulence in obtaining grain collisional velocities -- the kinetic energy spectrum and the turbulence autocorrelation time -- in the context of the turbulence generated by the magneto-rotational instability (MRI). We carry out numerical simulations of the MRI as well as driven turbulence, for a range of physical and numerical parameters. We find that the convergence of the turbulence $\alpha$-parameter does not necessarily imply the convergence of the energy spectrum. The MRI turbulence is largely solenoidal, for which we observe a persistent kinetic energy spectrum of $k^{-4/3}$. The same is obtained for solenoidal driven turbulence with and without magnetic field, over more than 1 dex near the dissipation scale. This power-law slope appears to be converged in terms of numerical resolution, and to be due to the bottleneck effect. The kinetic energy in the MRI turbulence peaks at the fastest growing mode of the MRI. In contrast, the magnetic energy peaks at the dissipation scale. The magnetic energy spectrum in the MRI turbulence does not show a clear power-law range, and is almost constant over approximately 1 dex near the dissipation scale. The turbulence autocorrelation time is nearly constant at large scales, limited by the shearing timescale, and shows a power-law drop close to $k^{-1}$ at small scales, with a slope steeper than that of the eddy crossing time. The deviation from the standard picture of the Kolmogorov turbulence with the injection scale at the disk scale height can potentially have a significant impact on the grain collisional velocities.
- [7] arXiv:2002.05173 [pdf, other]
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Title: The Fifth Candidate for an Intermediate-mass Black Hole in the Galactic CenterComments: 8 pages, 4 figures, accepted for publication on the Astrophysical JournalSubjects: Astrophysics of Galaxies (astro-ph.GA)
We report the results of high-resolution molecular line observations of the high-velocity compact cloud HCN-0.085-0.094 with the Atacama Large Millimeter/submillimeter Array. The HCN J=4-3, HCO$^+$ J=4-3, and CS J=7-6 line images reveal that HCN-0.085-0.094 consists mainly of three small clumps with extremely broad velocity widths. Each of the three clumps has a 5.5 GHz radio continuum counterpart in its periphery toward Sgr A$^*$. The positional relationship indicates that their surfaces have been ionized by ultraviolet photons from young stars in the central cluster, suggesting the clumps are in close proximity to the Galactic nucleus. One of the three clumps has a ring-like structure with a very steep velocity gradient. This kinematical structure suggests an orbit around a point-like object with a mass of $\sim 10^4$ $M_\odot$. The absence of stellar counterparts indicates that the point-like object may be a quiescent black hole. This discovery adds another intermediate-mass black hole candidate in the central region of our Galaxy.
- [8] arXiv:2002.05178 [pdf, other]
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Title: The first blazar observed at z>6Authors: S. Belladitta, A. Moretti, A. Caccianiga, C. Spingola, P. Severgnini, R. Della Ceca, G. Ghisellini, D. Dallacasa, T. Sbarrato, C. Cicone, L. P. Cassarà, M. PedaniComments: 7 pages, 8 figures, 2 tables, Accepted to publication in A&A LettersSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
We present the discovery of PSO J030947.49+271757.31, the radio brightest (23.7 mJy at 1.4 GHz) active galactic nucleus (AGN) at z>6.0. It was selected by cross-matching the NRAO VLA Sky Survey and the Panoramic Survey Telescope and Rapid Response System PS1 databases and its high-z nature was confirmed by a dedicated spectroscopic observation at the Large Binocular Telescope. A pointed Neil Gehrels $Swift$ Observatory XRT observation allowed us to measure a flux of $\sim$3.4$\times$10$^{-14}$ erg s$^{-1}$ cm$^{-2}$ in the [0.5-10] keV energy band, which also makes this object the X-ray brightest AGN ever observed at z>6.0. Its flat radio spectrum ($\alpha_{\nu r}$<0.5), very high radio loudness (R>10$^3$), and strong X-ray emission, compared to the optical, support the hypothesis of the blazar nature of this source. %i.e. a radio-loud (RL) AGN with the relativistic jet pointed toward us. Assuming that this is the only blazar at this redshift in the surveyed area of sky, we derive a space density of blazars at z$\sim$6 and with M$_{1450 \mbox{\AA}}$ < -21.5 of 5.5$^{+11.2}_{-4.6}$$\times$10$^{-3}$ Gpc$^{-3}$. From this number, and assuming a reasonable value of the bulk velocity of the jet ($\Gamma$=10), we can also infer a space density of the entire radio-loud AGN population at z$\sim$6 with the same optical/UV absolute magnitude of 1.10$^{+2.53}_{-0.91}$ Gpc$^{-3}$. Larger samples of blazars will be necessary to better constrain these estimates.
- [9] arXiv:2002.05179 [pdf, other]
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Title: Deep Hubble Space Telescope Imaging on the Extended Ly$α$ Emission of a QSO at $z = 2.19$ with Damped Lyman Alpha System as a Natural CoronagraphAuthors: Jiani Ding, Zheng Cai, J. Xavier Prochaska, H.Finley, Xiaohui Fan, Zheng Zheng, H. Fathivavsari, P. PetitjeanSubjects: Astrophysics of Galaxies (astro-ph.GA)
Recent observations suggest that proximate damped Ly$\alpha$ (PDLA) systems can be used to study the host galaxies of Quasi-stellar objects (QSOs), because the PDLAs can block the bright point-spread-function (PSF) from central QSOs. Using six-orbits of narrowband imaging with $\it{HST}$/WFC3, we present the first high resolution narrowband image of the Ly$\alpha$ emission in the PDLA trough of the QSO SDSSJ115432.67-021537.9 . We detect one major component and one minor component in the narrowband imaging. Combining the $\it{HST}$/WFC3 imaging with deep Magellan/MagE spectra, we measure that the Ly$\alpha$ flux F$_{\rm{Ly\alpha}}$ = 1.56$\pm0.10 \times10^{-16}$ $\rm{erg\ s^{-1}\ cm^{-2}}$, which is among the luminous ($\approx$ 2.7 L$^{\star}_{\rm{Ly\alpha}}$) Ly$\alpha$ emitters at $\it{z} =$ 2.19. The $\rm{Ly\alpha}$-based star formation rate (SFR) is $\sim$ 7 $\textrm{M_{\sun} \ yr^{-1}}$. These observational results favor that the star formation from the host galaxy could be the main mechanism to power the Ly$\alpha$ emission. This new method sheds new light on the study of the kinematic structure and the spatial distribution of the extended Ly$\alpha$ emitting regions around the QSO host.
- [10] arXiv:2002.05182 [pdf, other]
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Title: Precision and consistency of astrocombsComments: 16 pages, 17 figures, accepted for publication in MNRASSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
Astrocombs are ideal spectrograph calibrators whose limiting precision can be derived using a second, independent, astrocomb system. We therefore analyse data from two astrocombs (one 18 GHz and one 25 GHz) used simultaneously on the HARPS spectrograph at the European Southern Observatory. The first aim of this paper is to quantify the wavelength repeatability achieved by a particular astrocomb. The second aim is to measure wavelength calibration consistency between independent astrocombs, that is to place limits or measure any possible zero-point offsets. We present three main findings, each with important implications for exoplanet detection, varying fundamental constant and redshift drift measurements. Firstly, wavelength calibration procedures are important: using multiple segmented polynomials within one echelle order results in significantly better wavelength calibration compared to using a single higher-order polynomial. Segmented polynomials should be used in all applications aimed at precise spectral line position measurements. Secondly, we found that changing astrocombs causes significant zero-point offsets ($\approx 60{\rm cms}^{-1}$ in our raw data) which were removed. Thirdly, astrocombs achieve a precision of $\lesssim 4{\rm cms}^{-1}$ in a single exposure ($\approx 10\% $ above the measured photon-limited precision) and $1 {\rm cms}^{-1}$ when time-averaged over a few hours, confirming previous results. Astrocombs therefore provide the technological requirements necessary for detecting Earth-Sun analogues, measuring variations of fundamental constants and the redshift drift.
- [11] arXiv:2002.05197 [pdf, other]
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Title: Optical characterization of the Keck Array and BICEP3 CMB Polarimeters from 2016 to 2019Authors: The BICEP/Keck Collaboration: T. St Germaine, P. A. R. Ade, Z. Ahmed, M. Amiri, D. Barkats, R. Basu Thakur, C. A. Bischoff, J. J. Bock, H. Boenish, E. Bullock, V. Buza, J. Cheshire, J. Connors, J. Cornelison, M. Crumrine, A. Cukierman, M. Dierickx, L. Duband, S. Fatigoni, J. P. Filippini, S. Fliescher, J. A. Grayson, G. Hall, M. Halpern, S. Harrison, S. R. Hildebrandt, G. C. Hilton, H. Hui, K. D. Irwin, J. Kang, K. S. Karkare, E. Karpel, S. Kefeli, S. A. Kernasovskiy, J. M. Kovac, C. L. Kuo, K. Lau, E. M. Leitch, K. G. Megerian, L. Moncelsi, T. Namikawa, C. B. Netterfield, H. T. Nguyen, R. O'Brient, R.W. Ogburn IV, S. Palladino, C. Pryke, B. Racine, C. D. Reintsema, S. Richter, A. Schillaci, R. Schwarz, C. D. Sheehy, A. Soliman, B. Steinbach, R. V. Sudiwala, K. L. Thompson, J. E. Tolan, et al. (15 additional authors not shown)Comments: 8 pages, 3 figures. Accepted by the Journal of Low Temperature Physics (Proceedings of the 18th International Workshop on Low Temperature Detectors)Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Astrophysics of Galaxies (astro-ph.GA)
The BICEP/Keck experiment (BK) is a series of small-aperture refracting telescopes observing degree-scale Cosmic Microwave Background (CMB) polarization from the South Pole in search of a primordial $B$-mode signature. This $B$-mode signal arises from primordial gravitational waves interacting with the CMB, and has amplitude parametrized by the tensor-to-scalar ratio $r$. Since 2016, BICEP3 and the Keck Array have been observing with 4800 total antenna-coupled transition-edge sensor detectors, with frequency bands spanning 95, 150, 220, and 270 GHz. Here we present the optical performance of these receivers from 2016 to 2019, including far-field beams measured in situ with an improved chopped thermal source and instrument spectral response measured with a field-deployable Fourier Transform Spectrometer. As a pair differencing experiment, an important systematic that must be controlled is the differential beam response between the co-located, orthogonally polarized detectors. We generate per-detector far-field beam maps and the corresponding differential beam mismatch that is used to estimate the temperature-to-polarization leakage in our CMB maps and to give feedback on detector and optics fabrication. The differential beam parameters presented here were estimated using improved low-level beam map analysis techniques, including efficient removal of non-Gaussian noise as well as improved spatial masking. These techniques help minimize systematic uncertainty in the beam analysis, with the goal of constraining the bias on $r$ induced by temperature-to-polarization leakage to be subdominant to the statistical uncertainty. This is essential as we progress to higher detector counts in the next generation of CMB experiments.
- [12] arXiv:2002.05218 [pdf, other]
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Title: The variable shadow of M87*Authors: Philipp Arras, Philipp Frank, Philipp Haim, Jakob Knollmüller, Reimar Leike, Martin Reinecke, Torsten EnßlinComments: 24 pages, 6 figures, 4 tablesSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Astrophysics of Galaxies (astro-ph.GA)
Observing the dynamics of compact astrophysical objects provides insights into their inner workings and allows to probe physics under extreme conditions. The immediate vicinity of an active supermassive black hole with its event horizon, photon ring, accretion disk, and relativistic jets is a perfect place to study general relativity, magneto-hydrodynamics, and high energy plasma physics. The recent observations of the black hole shadow of M87* with Very Long Baseline Interferometry (VLBI) by the Event Horizon Telescope (EHT) open the possibility to investigate dynamical processes there on timescales of days. In this regime, radio astronomical imaging algorithms are brought to their limits. Compared to regular radio interferometers, VLBI networks have fewer antennas. The resulting sparser sampling of the Fourier sky can only be partly compensated by co-adding observations from different days, as the source changes. Here, we present an imaging algorithm that copes with the data scarcity and the source's temporal evolution, while simultaneously providing uncertainty quantification on all results. Our algorithm views the imaging task as a Bayesian inference problem of a time-varying flux density, exploits the correlation structure between time frames, and reconstructs a whole, $(2+1+1)$-dimensional time-variable and spectral-resolved image at once. We apply the method to the EHT observation of M87* and validate our approach on synthetic data. The obtained first time-resolved reconstruction of M87* indicates varying structures on and outside the emission ring on a time scale of days.
- [13] arXiv:2002.05219 [pdf, other]
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Title: Characterizing the Sensitivity of 40 GHz TES Bolometers for BICEP ArrayAuthors: C. Zhang, P. A. R. Ade, Z. Ahmed, M. Amiri, D. Barkats, R. Basu Thakur, C. A. Bischoff, J. J. Bock, H. Boenish, E. Bullock, V. Buza, J. Cheshire, J. Connors, J. Cornelison, M. Crumrine, A. Cukierman, M. Dierickx, L. Duband, S. Fatigoni, J. P. Filippini, G. Hall, M. Halpern, S. Harrison, S. Henderson, S. R. Hildebrandt, G. C. Hilton, H. Hui, K. D. Irwin, J. Kang, K. S. Karkare, E. Karpel, S. Kefeli, J. M. Kovac, C. L. Kuo, K. Lau, K. G. Megerian, L. Moncelsi, T. Namikawa, H. T. Nguyen, R. O'Brient, S. Palladino, N. Precup, T. Prouvé, C. Pryke, B. Racine, C. D. Reintsema, S. Richter, A. Schillaci, B. Schmitt, R. Schwarz, C. D. Sheehy, A. Soliman, T. St. Germaine, B. Steinbach, R. V. Sudiwala, K. L. Thompson, C. Tucker, A. D. Turner, C. Umiltà, A. G. Vieregg, A. Wandui, A. C. Weber, et al. (7 additional authors not shown)Comments: Accepted for publication in Journal of Low Temperature PhysicsSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Cosmology and Nongalactic Astrophysics (astro-ph.CO); Instrumentation and Detectors (physics.ins-det)
The BICEP/Keck (BK) experiment aims to detect the imprint of primordial gravitational waves in the Cosmic Microwave Background polarization, which would be direct evidence of the inflation theory. While the tensor-to-scalar ratio has been constrained to be r_0.05 < 0.06 at 95% c.l., further improvements on this upper limit are hindered by polarized Galactic foreground emissions and removal of gravitational lensing polarization. The 30/40 GHz receiver of the BICEP Array (BA) will deploy at the end of 2019 and will constrain the synchrotron foreground with unprecedented accuracy within the BK sky patch. We will show the design of the 30/40 GHz detectors and test results summarizing its performance. The low optical and atmospheric loading at these frequencies requires our TES detectors to have low saturation power in order to be photon-noise dominated. To realize the low thermal conductivity required from a 250 mK base temperature, we developed new bolometer leg designs. We will present the relevant measured detector parameters: G, Tc, Rn, Psat , and spectral bands, and noise spectra. We achieved a per bolometer NEP including all noise components of 2.07E-17 W/sqrt(Hz), including an anticipated photon noise level 1.54E-17 W/sqrt(Hz).
- [14] arXiv:2002.05228 [pdf, other]
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Title: Design and performance of the first BICEP Array receiverAuthors: A. Schillaci, P. A. R. Ade, Z. Ahmed, M. Amiri, D. Barkats, R. Basu Thakur, C. A. Bischoff, J. J. Bock, H. Boenish, E. Bullock, V. Buza, J. Cheshire, J. Connors, J. Cornelison, M. Crumrine, A. Cukierman, M. Dierickx, L. Duband, S. Fatigoni, J. P. Filippini, G. Hall, M. Halpern, S. Harrison, S. Henderson, S. R. Hildebrandt, G. C. Hilton, H. Hui, K. D. Irwin, J. Kang, K. S. Karkare, E. Karpel, S. Kefeli, J. M. Kovac, C. L. Kuo, K. Lau, K. G. Megerian, L. Moncelsi, T. Namikawa, H. T. Nguyen, R. O'Brient, S. Palladino, N. Precup, T. Prouvé, C. Pryke, B. Racine, C. D. Reintsema, S. Richter, B. Schmitt, R. Schwarz, C. D. Sheehy, A. Soliman, T. St. Germaine, B. Steinbach, R. V. Sudiwala, K. L. Thompson, C. Tucker, A. D. Turner, C. Umiltà, A. G. Vieregg, A. Wandui, A. C. Weber, D. V. Wiebe, et al. (7 additional authors not shown)Comments: 9 pages, 5 figures, presented at LTD18 in Milan (July 2019), accepted on JLTP (February 2020)Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
Branches of cosmic inflationary models, such as slow-roll inflation, predict a background of primordial gravitational waves that imprints a unique odd-parity B-mode pattern in the Cosmic Microwave Background (CMB) at amplitudes that are within experimental reach. The BICEP/Keck (BK) experiment targets this primordial signature, the amplitude of which is parameterized by the tensor-to-scalar ratio r, by observing the polarized microwave sky through the exceptionally clean and stable atmosphere at the South Pole. B-mode measurements require an instrument with exquisite sensitivity, tight control of systematics, and wide frequency coverage to disentangle the primordial signal from the Galactic foregrounds. BICEP Array represents the most recent stage of the BK program, and comprises four BICEP3-class receivers observing at 30/40, 95, 150 and 220/270 GHz. The 30/40 GHz receiver will be deployed at the South Pole during the 2019/2020 austral summer. After 3 full years of observations with 30,000+ detectors, BICEP Array will measure primordial gravitational waves to a precision $\sigma(r)$ between 0.002 and 0.004, depending on foreground complexity and the degree of lensing removal. In this paper we give an overview of the instrument, highlighting the design features in terms of cryogenics, magnetic shielding, detectors and readout architecture as well as reporting on the integration and tests that are ongoing with the first receiver at 30/40 GHz.
- [15] arXiv:2002.05243 [pdf, other]
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Title: Irradiated ocean planets bridge super-Earth and sub-Neptune populationsAuthors: Olivier Mousis, Magali Deleuil, Artyom Aguichine, Emmanuel Marcq, Joseph Naar, Lorena Acuña Aguirre, Bastien Brugger, Thomas GoncalvesComments: 13 pages, 2 figures, submittedSubjects: Earth and Planetary Astrophysics (astro-ph.EP)
With radii ranging between those of the Earth (1 Rearth) and Neptune (~3.9 Rearth), small planets constitute more than half of the inventory of the 4000-plus exoplanets discovered so far. This population follows a bimodal distribution peaking at ~1.3 Rearth (super-Earths) and 2.4 Rearth (sub-Neptunes), with few planets in between. Smaller planets are sufficiently dense to be rocky, but those with radii larger than ~1.6 Rearth are thought to display large amounts of volatiles, including in many cases hydrogen/helium gaseous envelopes up to ~30% of the planetary mass. With orbital periods less than 100 days, these low-mass planets are highly irradiated and their origin, evolution, and possible links are still debated. Here we show that close-in ocean planets affected by greenhouse effect display hydrospheres in supercritical state, which generate inflated atmospheres without invoking the presence of large H/He gaseous envelopes. We derive a new set of mass-radius relationships for ocean planets with different compositions and different equilibrium temperatures, well adapted to low-density sub-Neptune planets. Our model suggests that super-Earths and sub-Neptunes could belong to the same family of planets. The differences between their interiors could simply result from the variation of the water content in those planets. Close-in sub-Neptunes would have grown from water-rich building blocks compared to super-Earths, and not concurrently from gas coming from the protoplanetary disk. This implies that small planets should present similar formation conditions, which resemble those known for the terrestrial and dwarf planets in the solar system.
- [16] arXiv:2002.05254 [pdf, other]
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Title: Optical Design and Characterization of 40-GHz Detector and Module for the BICEP ArrayAuthors: A. Soliman, P. A. R. Ade, Z. Ahmed, M. Amiri, D. Barkats, R. Basu Thakur, C. A. Bischoff, J. J. Bock, H. Boenish, E. Bullock, V. Buza, J. Cheshire, J. Connors, J. Cornelison, M. Crumrine, A. Cukierman, M. Dierickx, L. Duband, S. Fatigoni, J. P. Filippini, G. Hall, M. Halpern, S. Harrison, S. Henderson, S. R. Hildebrandt, G. C. Hilton, H. Hui, K. D. Irwin, J. Kang, K. S. Karkare, E. Karpel, S. Kefeli, J. M. Kovac, C. L. Kuo, K. Lau, K. G. Megerian, L. Moncelsi, T. Namikawa, H. T. Nguyen, R. OBrient, S. Palladino, T. Prouve, N. Precup, C. Pryke, B. Racine, C. D. Reintsema, S. Richter, B. Schmitt, R. Schwarz, C. D. Sheehy, A. Schillaci, T. St. Germaine, B. Steinbach, R. V. Sudiwala, K. L. Thompson, C. Tucker, A. D. Turner, C. Umilta, A. G. Vieregg, A. Wandui, A. C. Weber, D. V. Wiebe, J. Willmert, et al. (6 additional authors not shown)Comments: 8 pages, 7 figures, Accepted by the Journal of Low Temperature Physics (Proceedings of the 18th International Workshop on Low Temperature Detectors)Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)
Families of cosmic inflation models predict a primordial gravitational-wave background that imprints B-mode polarization pattern in the Cosmic Microwave Background (CMB). High sensitivity instruments with wide frequency coverage and well-controlled systematic errors are needed to constrain the faint B-mode amplitude. We have developed antenna-coupled Transition Edge Sensor (TES) arrays for high-sensitivity polarized CMB observations over a wide range of millimeter-wave bands. BICEP Array, the latest phase of the BICEP/Keck experiment series, is a multi-receiver experiment designed to search for inflationary B-mode polarization to a precision $\sigma$(r) between 0.002 and 0.004 after 3 full years of observations, depending on foreground complexity and the degree of lensing removal. We describe the electromagnetic design and measured performance of BICEP Array low-frequency 40-GHz detector, their packaging in focal plane modules, and optical characterization including efficiency and beam matching between polarization pairs. We summarize the design and simulated optical performance, including an approach to improve the optical efficiency due to mismatch losses. We report the measured beam maps for a new broad-band corrugation design to minimize beam differential ellipticity between polarization pairs caused by interactions with the module housing frame, which helps minimize polarized beam mismatch that converts CMB temperature to polarization ($T \rightarrow P$) anisotropy in CMB maps.
- [17] arXiv:2002.05275 [pdf, other]
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Title: Lithium Enrichment Signatures of Planetary Engulfment Events in Evolved StarsComments: 19 pages, 8 figuresSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP)
Planetary engulfment events have long been proposed as a lithium (Li) enrichment mechanism contributing to the population of Li-rich giants $(A(\mathrm{Li}) \geq 1.5$ dex). Using $GALAH$ survey data and MESA stellar models, we calculate the strength and duration of the Li enrichment signature produced in the convective envelope of a host star that has engulfed a hot Jupiter (HJ) companion. We consider solar-metallicity stars in the mass range of $1.0-2.0~\mathrm{M_{\odot}}$ and the Li supplied by a HJ of $1.0~\mathrm{M_{J}}$. We explore engulfment events that occur near the main sequence turn-off (MSTO) and out to orbital separations of $R_{\star}{\sim}~0.1~\mathrm{AU}= 22~\mathrm{R_{\odot}}$. We map our results onto the Hertzsprung-Russell (H-R) Diagram, revealing the parameter space where planetary engulfment events produce significant Li enrichment signatures. We also map the associated survival times of these signatures, which range across 9 orders of magnitude. Our calculations indicate that if the HJ engulfment event occurs near the MSTO or on the subgiant branch, Li enrichment can be measured at a $5\sigma$ confidence level and with strengths that exceed meteoritic abundance measurements. Moreover, for stars of $1.4~\mathrm{M_{\odot}}$, these signatures are predicted to survive for up to 1 Gyr. We determine that Li enrichment beyond the subgiant branch must be produced by other mechanisms, such as the Cameron-Fowler process or accretion of material from an AGB companion.
- [18] arXiv:2002.05280 [pdf, other]
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Title: Measurements of Nuclear Reactions that Create and Destroy Li and Be during BBNAuthors: Barry DavidsComments: 6 pages, 3 figures, and 3 tables; contribution to proceedings of the conference "Lithium in the Universe: To Be or not to Be"Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
I review measurements of the most important reactions involved in the creation and destruction of Li and Be during big bang nucleosynthesis (BBN) as well as their uncertainties and the relative contributions they make to the uncertainty in the primordial $^7$Li abundance ($^7$Li/H). Examining the sensitivity of calculated $^7$Li/H to these reactions as predicted by different BBN codes I find no significant differences. I compare my calculation of primordial $^7$Li/H to some recently published values and conclude that in the absence of a major undetected experimental blunder, nuclear physics uncertainties cannot account for the cosmological Li problem. With an estimated 13% uncertainty in the calculated abundance, the discrepancy with observation amounts to some $4.6\sigma$.
- [19] arXiv:2002.05290 [pdf, ps, other]
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Title: Running vacuum model in non-flat universeComments: 13 pages, 4 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
We investigate observational constraints on the running vacuum model (RVM) of $\Lambda=3\nu (H^{2}+K/a^2)+c_0$ in the spatially curved universe, where $\nu$ is the model parameter, $K$ corresponds to the spatial curvature constant, and $c_{0}$ is a constant defined by the boundary conditions. As $\dot{\Lambda} \ne 0$, there are energy exchanges between vacuum, matter and radiation in RVM. We study the "geometrical degeneracy" of RVM on the CMB power spectra. By fitting the cosmological data, we find that the values of $\chi^2$ in RVM and $\Lambda$CDM are similar to each other for the non-flat universe. Explicitly, we obtain the constraints of $\nu\leq O(10^{-4})$ (68 $\%$ C.L.) and $|\Omega_K|\leq O(10^{-2})$ (95 $\%$ C.L.) in our study. In addition, we show that the cosmological constraints of $\Sigma m_{\nu}=0.416^{+0.311}_{-0.407}$ (RVM) and $\Sigma m_{\nu}=0.497^{+0.335}_{-0.387}$ ($\Lambda$CDM) at 95$\%$ C.L. for the neutrino mass sum are relaxed in both models in the spatially curved universe.
- [20] arXiv:2002.05310 [pdf, ps, other]
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Title: One Planet or Two Planets? The Ultra-sensitive Extreme-magnification Microlensing Event KMT-2019-BLG-1953Authors: Cheongho Han, Doeon Kim, Youn Kil Jung, Andrew Gould, Ian A. Bond, Michael D. Albrow, Sun-Ju Chung, Kyu-Ha Hwang, Chung-Uk Lee, Yoon-Hyun Ryu, In-Gu Shin, Yossi Shvartzvald, Jennifer C. Yee, Weicheng Zang, Sang-Mok Cha, Dong-Jin Kim, Hyoun-Woo Kim, Seung-Lee Kim, Dong-Joo Lee, Yongseok Lee, Byeong-Gon Park, Richard W. Pogge, Woong-Tae Kim, Fumio Abe, Richard Barry, David P. Bennett, Aparna Bhattacharya, Martin Donachie, Hirosane Fujii, Akihiko Fukui, Yoshitaka Itow, Yuki Hirao, Rintaro Kirikawa, Iona Kondo, Naoki Koshimoto, Man Cheung Alex Li, Yutaka Matsubara, Yasushi Muraki, Shota Miyazaki, Masayuki Nagakane, Clément Ranc, Nicholas J. Rattenbury, Yuki Satoh, Hikaru Shoji, Haruno Suematsu, Takahiro Sumi, Daisuke Suzuki, Yuzuru Tanaka, Paul J. Tristram, Tsubasa Yamawaki, Atsunori YoneharaComments: 9 pages, 7 figuresSubjects: Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)
We report a strong candidate multiplanetary system found by analyzing a very high-magnification ($A\sim 900$) microlensing event KMT-2019-BLG-1953. A single-lens single-source (1L1S) model appears to approximately delineate the observed light curve, but the residuals from the model exhibit small but obvious deviations in the peak region. Although models with a binary lens (2L1S) and binary source (1L2S) improve the fit, there still remain small residuals from the models, and these residuals can be explained by either triple-lens (3L1S) or binary-lens binary-source (2L2S) models. Among the two models, we judge that the 3L1S model provides a more plausible interpretation first because the signature of the second planet according to the 3L1S solution appears in the region where it is expected, i.e., around the peak of a very high-magnification event, and second because the 2L2S model is physically implausible. From the 3L1S modeling, we find four sets of solutions caused by the close/wide degeneracies in the planet separations from the host, $s_2$ and $s_3$. From Bayesian analysis, we estimate that the host of the planets has a mass of $M_{\rm host}=0.31^{+0.37}_{-0.17}~M_\odot$ and that the planetary system is located at a distance of $D_{\rm L}=7.04^{+1.10}_{-1.33}~{\rm kpc}$ toward the Galactic center. The mass of the first planet, $M_2$, is in the range of $0.42 \lesssim M_2/M_{\rm J}\lesssim 0.62$ and that of the second planet, $M_3$, is in the ranges of $0.27 \lesssim M_3/M_{\rm J}\lesssim 0.48$ for solutions with $s_3<1.0$ and $2.1 \lesssim M_3/M_{\rm J} \lesssim 2.8$ for solutions with $s_3>1.0$.
- [21] arXiv:2002.05313 [pdf, other]
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Title: Wide field-of-view study of the Eagle Nebula with the Fourier transform imaging spectrograph SITELLE at CFHTComments: 21 pages, accepted for publication in A&ASubjects: Astrophysics of Galaxies (astro-ph.GA)
We present the very first wide-field, 11 by 11 arcmin, optical spectral mapping of M16, one of the most famous star-forming regions in the Galaxy. The data were acquired with the new imaging Fourier transform spectrograph SITELLE mounted on the Canada-France-Hawaii Telescope (CFHT). We obtained three spectral cubes with R=10'000 (SN1 filter), 1500 (SN2 filter) and 600 (SN3 filter), centered on the Pillars of Creation and the HH216 flow, covering the main optical nebular emission lines: [O II]3726,29 (SN1), Hb, [O III]4959,5007 (SN2), [N II]6548,84, Ha, and [S II]6717,31 (SN3). We validate the performance, calibration, and data reduction of SITELLE, and analyze the structures in the large field-of-view in terms of their kinematics and nebular emission. We compared the SITELLE data to MUSE integral field observations and other spectroscopic and narrow-band imaging data to validate the performance of SITELLE. We computed gas-phase metallicities via the strong-line method, performed a pixel-by-pixel fit to the main emission lines to derive kinematics of the ionized gas, computed the mass-loss rate of the Eastern pillar (the Spire), and combined the SITELLE data with near-infrared narrow-band imaging to characterize the HH216 flow. The comparison with previously published fluxes demonstrates very good agreement. We disentangle the dependence of the gas-phase metallicities (derived via abundance-tracing line ratios) on the degree of ionization and obtain metallicities that are in excellent agreement with the literature. We confirm the bipolar structure of HH216, find evidence for episodic accretion from the source of the flow, and identify its likely driving source. We compute the mass-loss rate of the Spire pillar on the East side of the H II region and find excellent agreement with the correlation between the mass-loss rate and the ionizing photon flux from the nearby cluster NGC6611.
- [22] arXiv:2002.05343 [pdf, other]
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Title: The origin of dust in galaxies across cosmic timeComments: 19 pages, 14 figures, accepted for publication in MNRASSubjects: Astrophysics of Galaxies (astro-ph.GA)
We study the dust evolution in galaxies by implementing a detailed dust prescription in the SAGE semi-analytical model for galaxy formation. The new model, called Dusty SAGE, follows the condensation of dust in the ejecta of type II supernovae and asymptotic giant branch (AGB) stars, grain growth in the dense molecular clouds, destruction by supernovae shocks, and the removal of dust from the ISM by star formation, reheating, inflows and outflows. Our model successfully reproduces the observed dust mass function at redshift z = 0 and the observed scaling relations for dust across a wide range of redshifts. We find that the dust mass content in the present Universe is mainly produced via grain growth in the interstellar medium (ISM). By contrast, in the early Universe, the primary production mechanism for dust is the condensation in stellar ejecta. The shift of the significant production channel for dust characterises the scaling relations of dust-to-gas (DTG) and dust-to-metal (DTM) ratios. In galaxies where the grain growth dominates, we find positive correlations for DTG and DTM ratios with both metallicity and stellar mass. On the other hand, in galaxies where dust is produced primarily via condensation, we find negative or no correlation for DTM and DTG ratios with either metallicity or stellar mass. In agreement with observation showing that the circumgalactic medium (CGM) contains more dust than the ISM, our model also shows the same trend for z < 4. Our semi-analytic model is publicly available at https: //github.com/dptriani/dusty-sage.
- [23] arXiv:2002.05361 [pdf, other]
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Title: Development of Linear Astigmatism Free -- Three Mirror System (LAF-TMS)Authors: Woojin Park, Seunghyuk Chang, Jae Hyuk Lim, Sunwoo Lee, Hojae Ahn, Yunjong Kim, Sanghyuk Kim, Arvid Hammar, Byeongjoon Jeong, Geon Hee Kim, Hyoungkwon Lee, Dae Wook Kim, Soojong PakComments: 26 pages, 13 figures, will be published in Publications of the Astronomical Society of the PacificSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)
We present the development of Linear Astigmatism Free - Three Mirror System (LAF-TMS). This is a prototype of an off-axis telescope that enables very wide field of view (FoV) infrared satellites that can observe Paschen-$\alpha$ emission, zodiacal light, integrated star light, and other infrared sources. It has the entrance pupil diameter of 150 mm, the focal length of 500 mm, and the FoV of 5.5$^\circ$ $\times$ 4.1$^\circ$. LAF-TMS is an obscuration-free off-axis system with minimal out-of-field baffling and no optical support structure diffraction. This optical design is analytically optimized to remove linear astigmatism and to reduce high-order aberrations. Sensitivity analysis and Monte-Carlo simulation reveal that tilt errors are the most sensitive alignment parameters that allow $\sim$1$^\prime$. Optomechanical structure accurately mounts aluminum mirrors, and withstands satellite-level vibration environments. LAF-TMS shows optical performance with 37 $\mu$m FWHM of the point source image satisfying Nyquist sampling requirements for typical 18 $\mu$m pixel Infrared array detectors. The surface figure errors of mirrors and scattered light from the tertiary mirror with 4.9 nm surface micro roughness may affect the measured point spread function (PSF). Optical tests successfully demonstrate constant optical performance over wide FoV, indicating that LAF-TMS suppresses linear astigmatism and high-order aberrations.
- [24] arXiv:2002.05362 [pdf]
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Title: MeV Gamma-ray imaging spectroscopic observation for Galactic Center and Cosmic Background MeV gammas by SMILE-2+ Balloon ExperimentAuthors: Toru Tanimori (on behalf of SMILE project)Comments: 4pages, Accepted for Proceedings of TAUP2019Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)
Recently, there appears lots of papers on the possibility of light Dark Matter (DM) in MeV and sub-GeV scale. Until now, only INTEGRAL and COMPTEL provided experimental data of 511keV of galactic center, and two spectra of Galactic Diffuse MeV gammas (GDMG), and COMPTEL provided the Cosmic Background MeV gammas (CBMG) for wide sky for indirect detection of light DMs. However except 511keV, those spectra for diffuse gammas included large statistical and systematic errors in spite of 10 years observation, since both two instruments suffered from severe background radiation in space. In 2018 April, we (SMILE-project in Comic-ray Group of Kyoto University) have observed MeV gamma rays for whole southern sky by Electron Tracking Compton Camera (ETCC) using JAXA balloon at Australia during one-day. (SMILE2+ Project) By measuring all parameters of Compton scattering in every gamma, ETCC has achieved for the first time to obtain the complete direction of MeV gammas as same as optical telescopes, and also to distinguish signal gammas from huge background gammas in space clearly. In this observation, ETCC with a large Field of View of 3sr observed MeV gammas from 3/5 of all sky including galactic centre, a half disk, crab, and most of CBMG By reconstructing the Compton process, we successfully obtained pure comic gammas by reducing background by more 2 orders, which is clearly certificated by the clear enhancement of detected gamma flux with ~30% during galactic center passing through the Field of View, which is consistent with the ratio of CBMG and GDMG. Now 511keV gammas GDMG are preliminarily detected with ~5 and >10 sigma respectively around Galactic Centre. Also we have obtained near 105events of CBMG in with quite low background of only a few 10% in total CBMG events. Thus we obtained good data for both with high statistics and very low systematics even one day observation.
- [25] arXiv:2002.05386 [pdf, other]
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Title: Observable Small-scale Effects of Thermal InflationAuthors: Heeseung ZoeSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
Thermal inflation, a brief low energy inflation after the primordial inflation, resolves the moduli problem in the context of supersymmetric cosmology. In the thermal inflation scenario, the primordial power spectrum is modestly redshifted on large scales, but suppressed by a factor of 1/50 on scales smaller than the horizon size at the beginning of thermal inflation. We compare the thermal inflation model with the warm dark matter and $\Lambda$CDM scenarios by studying CMB spectral distortions, halo abundances, and 21cm hydrogen lines.
- [26] arXiv:2002.05415 [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 A&ASubjects: Solar and Stellar Astrophysics (astro-ph.SR); High Energy Astrophysical Phenomena (astro-ph.HE)
In the last years, a peculiarity of some Be stars - their association with unusually hard and intense X-ray emission - was shown to extend beyond a mere few cases. In this paper, we continue our search for new cases by performing a limited survey of 18 Be stars using XMM-Newton. The targets were selected either on the basis of a previous X-ray detection (Exosat, ROSAT, XMM-slew survey) without spectral information available, or because of the presence of a peculiar spectral variability. Only two targets remain undetected in the new observations and three other stars only display faint and soft X-rays. Short-term and/or long-term variations were found in one third of the sample. The spectral characterization of the X-ray brightest 13 stars of the sample led to the discovery of three new gamma Cas (HD44458, HD45995, V558Lyr), bringing the total to 25 known cases, and another gamma Cas candidate (HD120678), bringing the total to 2.
- [27] arXiv:2002.05434 [pdf, ps, other]
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Title: Triggering mixing and deceleration in FRI jets: a solutionAuthors: Manel PeruchoComments: Accepted for publication in MNRAS LettersSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); Astrophysics of Galaxies (astro-ph.GA)
Since Fanaroff & Riley (1974) reported the morphological and brightness dichotomy of radiogalaxies, and it became clear that the symmetric emission from jets and counter-jets in the centre-brightened, less powerful, FRI sources could be caused by jet deceleration, many works have addressed different mechanisms that could cause this difference. Recent observational results seem to indicate that the deceleration must be caused by the development of small-scale instabilities that force mixing at the jet boundary. According to these results, the mixing layer expands and propagates down to the jet axis along several kiloparsecs, until it covers the whole jet cross-section. Several candidate mechanisms have been proposed as the initial trigger for the generation of such mixing layer. However, the instabilities proposed so far do not fully manage to explain the observations of FRI jets and/or require a triggering mechanism. Therefore, there is not still a satisfactory explanation for the original cause of jet deceleration. In this letter, I show that the penetration (and exit) of stars from jets could give the adequate explanation by means of creating a jet-interstellar medium mixing layer that expands across the jet.
- [28] arXiv:2002.05436 [pdf, ps, other]
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Title: Loss of toroidal magnetic flux by emergence of bipolar magnetic regionsComments: A&A acceptedSubjects: Solar and Stellar Astrophysics (astro-ph.SR)
The polarity of the toroidal magnetic field in the solar convection zone periodically reverses in the course of the 11/22-year solar cycle. Among the various processes that contribute to the removal of `old-polarity' toroidal magnetic flux is the emergence of flux loops forming bipolar regions at the solar surface. We quantify the loss of subsurface net toroidal flux by this process. To this end, we determine the contribution of an individual emerging bipolar loop and show that it is unaffected by surface flux transport after emergence. Together with the linearity of the diffusion process this means that the total flux loss can be obtained by adding the contributions of all emerging bipolar magnetic regions. The resulting total loss rate of net toroidal flux amounts to 1.3 X 10^{15} Mx/s during activity maxima and 6.1 X 10^{14} Mx/s during activity minima, to which ephemeral regions contribute about 90% and 97%, respectively. This rate is consistent with the observationally inferred loss rate of toroidal flux into interplanetary space and corresponds to a decay time of the subsurface toroidal flux of about 12 years, also consistent with a simple estimate based on turbulent diffusivity. Consequently, toroidal flux loss by flux emergence is a relevant contribution to the budget of net toroidal flux in the solar convection zone. That the toroidal flux loss rate due to flux emergence is consistent with what is expected from turbulent diffusion, and that the corresponding decay time is similar to the length of the solar cycle are important constraints for understanding the solar cycle and the Sun's internal dynamics.
- [29] arXiv:2002.05453 [pdf, ps, other]
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Title: Outer Planet Single-Transit Detections with LSSTAuthors: Derek BuzasiComments: Accepted for publication in Research Notes of the American Astronomical Society (RNAAS)Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
In our solar system massive outer planets dominate in terms of both mass and angular momentum, but few such planets are among the more than 4000 currently confirmed exoplanets, and none of these have accurately determined densities. Here I examine the detection rate of single-transit events anticipated from the LSST deep drilling fields for such planets with periods of 2 - 25 years. Using conservative detection criteria, I anticipate 3-30 such detections over the 10-year period of the project, though distinguishing detections from false positives may prove challenging. However, these few detections are likely to be of great value in understanding the formation, dynamics, and diversity of exoplanet systems.
- [30] arXiv:2002.05480 [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)
Context. Low-mass protostars drive powerful molecular outflows that can be observed with mm and sub-mm telescopes. Various sulfuretted species are known to be bright in shocks and could be used to infer the physical and chemical conditions throughout the observed outflows. Aims. The evolution of sulfur chemistry is studied along the outflows driven by the NGC1333-IRAS4A protobinary system located in the Perseus cloud to constrain the physical and chemical processes at work in shocks. Methods. We observed various transitions from OCS, CS, SO, and SO$_2$ towards NGC1333-IRAS4A in the 1.3, 2, and 3mm bands using the IRAM NOEMA array and we interpreted the observations through the use of the Paris-Durham shock model. Results. The targeted species clearly show different spatial emission along the two outflows driven by IRAS4A. OCS is brighter on small and large scales along the south outflow driven by IRAS4A1, whereas SO$_2$ is detected rather along the outflow driven by IRAS4A2 that is extended along the north east - south west (NE-SW) direction. Column density ratio maps estimated from a rotational diagram analysis allowed us to confirm a clear gradient of the OCS/SO$_2$ column density ratio between the IRAS4A1 and IRAS4A2 outflows. SO is detected at extremely high radial velocity up to 25 km/s relative to the source velocity, clearly allowing us to distinguish the two outflows on small scales. Conclusions. The observed chemical differentiation between the two outflows of the IRAS4A system could be explained by a different chemical history. The outflow driven by IRAS4A1 is likely younger and more enriched in species initially formed in interstellar ices, such as OCS, and recently sputtered into the shock gas. In contrast, the longer and likely older outflow triggered by IRAS4A2 is more enriched in species that have a gas phase origin, such as SO$_2$.
- [31] arXiv:2002.05506 [pdf, other]
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Title: Characterising lognormal fractional-Brownian-motion density fields with a Convolutional Neural NetworkSubjects: Astrophysics of Galaxies (astro-ph.GA)
In attempting to quantify statistically the density structure of the interstellar medium, astronomers have considered a variety of fractal models. Here we argue that, to properly characterise a fractal model, one needs to define precisely the algorithm used to generate the density field, and to specify -- at least -- three parameters: one parameter constrains the spatial structure of the field; one parameter constrains the density contrast between structures on different scales; and one parameter constrains the dynamic range of spatial scales over which self-similarity is expected (either due to physical considerations, or due to the limitations of the observational or numerical technique generating the input data). A realistic fractal field must also be noisy and non-periodic. We illustrate this with the exponentiated fractional Brownian motion (xfBm) algorithm, which is popular because it delivers an approximately lognormal density field, and for which the three parameters are, respectively, the power spectrum exponent, $\beta$, the exponentiating factor, ${\cal S}$, and the dynamic range, ${\cal R}$. We then explore and compare two approaches that might be used to estimate these parameters: Machine Learning and the established $\Delta$-Variance procedure. We show that for $2\leq\beta \leq 4$ and $0\leq{\cal S}\leq 3$, a suitably trained Convolutional Neural Network is able to estimate objectively both $\beta$ (with root-mean-square error $\epsilon_{_\beta}\sim 0.12$) and ${\cal S}$ (with $\epsilon_{_{\cal S}}\sim 0.29$). $\;\Delta$-variance is also able to estimate $\beta$, albeit with a somewhat larger error ($\epsilon_{_\beta}\sim 0.17$) and with some human intervention, but is not able to estimate ${\cal S}$.
- [32] arXiv:2002.05528 [pdf, ps, other]
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Title: Measuring eccentricity of binary black holes in GWTC-1 by using inspiral-only waveformComments: 10 pages, 7 figures, 4 tables, submitted to MNRASSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); General Relativity and Quantum Cosmology (gr-qc)
In this paper, we estimate the eccentricity of the 10 BBHs in GWTC-1 by using the inspiral-only BBH waveform template EccentricFD. Firstly, we test our method with simulated eccentric BBHs. Afterwards we apply the method to the real BBH gravitational wave data. We find that the BBHs in GWTC-1 except GW151226, GW170608 and GW170729 admit almost zero eccentricity. Their upper limits on eccentricity rang from 0.033 to 0.084 with 90% credible interval at the reference frequency 10Hz. And their median eccentricities are 0.000. For GW151226, GW170608 and GW170729, the upper limits are higher than 0.1. But the median eccentricities are respectively 0.000, 0.064 and 0.000. We also point out the limitations of the inspiral-only waveform template in eccentricity measurement. The current eccentricity measurement results of GWTC-1 is not enough to constrain the formation mechanisms of BBHs, and more observational data are needed in the future.
- [33] arXiv:2002.05543 [pdf, ps, other]
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Title: A mid-infrared interferometric survey of the planet-forming region around young Sun-like starsComments: 4 pages, 2 figures, published in "Origins: From the Protosun to the First Steps of Life. Proceedings of the International Astronomical Union, Volume 345"Journal-ref: Origins: From the Protosun to the First Steps of Life. Proceedings of the International Astronomical Union, Volume 345, pp. 128-131 (2020)Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA)
We present our results from a mid-infrared interferometric survey targeted at the planet-forming region in the circumstellar disks around low- and intermediate-mass young stars. Our sample consist of 82 objects, including T Tauri stars, Herbig Ae stars, and young eruptive stars. Our main results are: 1) Disks around T Tauri stars are similar to those around Herbig Ae stars, but are relatively more extended once we account for stellar luminosity. 2) From the distribution of the sizes of the mid-infrared emitting region we find that inner dusty disk holes may be present in roughly half of the sample. 3) Our analysis of the silicate spectral feature reveals that the dust in the inner $\sim$1 au region of disks is generally more processed than that in the outer regions. 4) The dust in the disks of T Tauri stars typically show weaker silicate emission in the N band spectrum, compared to Herbig Ae stars, which may indicate a general difference in the disk structure. Our data products are available at VizieR, and at the following web page: this http URL
- [34] arXiv:2002.05555 [pdf, other]
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Title: High-resolution Spectroscopic Study of Dwarf Stars in the Northern Sky: Lithium, Carbon, and Oxygen AbundancesAuthors: Edita Stonkutė, Yuriy Chorniy, Gražina Tautvaišienė, Arnas Drazdauskas, Renata Minkevičiūtė, Šarūnas Mikolaitis, Hans Kjeldsen, Carolina von Essen, Erika Pakštienė, Vilius BagdonasComments: 17 pages, 15 figures. Published 2020 February 6, 2020. The Astronomical JournalJournal-ref: The Astronomical Journal, Volume 159, Number 3, 2020Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
Abundances of lithium, carbon, and oxygen have been derived using spectral synthesis for a sample of 249 bright F, G, and K Northern Hemisphere dwarf stars from the high-resolution spectra acquired with the VUES spectrograph at the Moletai Astronomical Observatory of Vilnius University. The sample stars have metallicities, effective temperatures, and ages between -0.7 and 0.4 dex; 5000 and 6900 K; 1 and 12 Gyr, accordingly. We confirm a so far unexplained lithium abundance decrease at supersolar metallicities - $A$(Li) in our sample stars, which drop by 0.7 dex in the [Fe/H] range from +0.10 to +0.55 dex. Furthermore, we identified stars with similar ages, atmospheric parameters, and rotational velocities, but with significantly different lithium abundances, which suggests that additional specific evolutionary factors should be taken into account while interpreting the stellar lithium content. Nine stars with predominantly supersolar metallicities, i.e. about 12 % among 78 stars with C and O abundances determined, have the C/O number ratios larger than 0.65, thus may form carbon-rich rocky planets. Ten planet-hosting stars, available in our sample, do not show a discernible difference from the stars with no planets detected regarding their lithium content.
- [35] arXiv:2002.05563 [pdf, other]
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Title: Neutrino mass and mass hierarchy in various dark energySubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
Combined with various cosmology observations, one can obtain constraints on the sum of the active neutrino masses $M_\nu$. However, the bounds on the sum of neutrino masses $M_\nu$ depend on the dark energy (DE) models. We consider three dark energy models, the cosmological constant ($\Lambda$CDM) model, a phenomenological emergent dark energy (PEDE) model and a model-independent quintessential parametrization (HBK). Based on these models with cosmic microwave background (CMB) data from Planck 2018, Baryon Acoustic Oscillations (BAO) measurements and Type Ia supernovae (SNe Ia) data, we obtain the bounds on total neutrino masses with the approximation of degenerate neutrino masses. In the HBK model, we conform the conclusion from a few pioneer works that the quintessence prior of dark energy tends to tighten the cosmological constraint on $M_\nu$. On the other hand, in the PEDE model, we get a larger $M_\nu$ and a nonzero lower bound. Besides, we also explore the correlation between three different neutrino hierarchies and dark energy models.
- [36] arXiv:2002.05581 [pdf, other]
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Title: Dust Devils on TitanComments: Accepted for publication in JGR: Planets; data and code available here - this https URLSubjects: Earth and Planetary Astrophysics (astro-ph.EP)
Conditions on Saturn's moon Titan suggest dust devils, which are convective, dust-laden plumes, may be active. Although the exact nature of dust on Titan is unclear, previous observations confirm an active aeolian cycle, and dust devils may play an important role in Titan's aeolian cycle, possibly contributing to regional transport of dust and even production of sand grains. The Dragonfly mission to Titan will document dust devil and convective vortex activity and thereby provide a new window into these features, and our analysis shows that associated winds are likely to be modest and pose no hazard to the mission.
- [37] arXiv:2002.05588 [pdf, ps, other]
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Title: On Carbon Nanotubes in the Interstellar MediumComments: 7 pages, 2 figures; accepted for publication in MNRASSubjects: Astrophysics of Galaxies (astro-ph.GA); Materials Science (cond-mat.mtrl-sci)
Since their discovery in 1991, carbon nanotubes (CNTs) -- a novel one-dimensional carbon allotrope -- have attracted considerable interest worldwide because of their potential technological applications such as electric and optical devices. In the astrophysical context, CNTs may be present in the interstellar space since many of the other allotropes of carbon (e.g., amorphous carbon, fullerenes, nanodiamonds, graphite, polycyclic aromatic hydrocarbons, and possibly graphene as well) are known to be widespread in the Universe, as revealed by presolar grains in carbonaceous primitive meteorites and/or by their fingerprint spectral features in astronomical spectra. In addition, there are also experimental and theoretical pathways to the formation of CNTs in the interstellar medium (ISM). In this work, we examine their possible presence in the ISM by comparing the observed interstellar extinction curve with the ultraviolet/optical absorption spectra experimentally obtained for single-walled CNTs of a wide range of diameters and chiralities. Based on the absence in the interstellar extinction curve of the ~4.5 and 5.25 eV $\pi$-plasmon absorption bands which are pronounced in the experimental spectra of CNTs, we place an upper limit of ~10 ppm of C/H (i.e., ~4% of the total interstellar C) on the interstellar CNT abundance.
- [38] arXiv:2002.05591 [pdf, other]
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Title: Shallow transit follow-up from NGTS: simultaneous observations of HD106315 with 11 identical telescopesAuthors: Alexis M. S. Smith, Philipp Eigmüller, Ramanathan Gurumoorthy, Szilárd Csizmadia, Daniel Bayliss, Matthew R. Burleigh, Juan Cabrera, Sarah L. Casewell, Anders Erikson, Michael R. Goad, Andrew Grange, James S. Jenkins, Don Pollacco, Heike Rauer, Liam Raynard, Stéphane Udry, Richard G. West, Peter J. WheatleyComments: 11 pages, 9 figures, 3 tables. Resubmitted to Astronomische Nachrichten following review and revisionSubjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)
The Next Generation Transit Survey (NGTS) is a photometric survey for transiting exoplanets, consisting of twelve identical 0.2-m telescopes. We report a measurement of the transit of HD106315c using a novel observing mode in which multiple NGTS telescopes observed the same target with the aim of increasing the signal-to-noise. Combining the data allows the robust detection of the transit, which has a depth less than 0.1 per cent, rivalling the performance of much larger telescopes. We demonstrate the capability of NGTS to contribute to the follow-up of K2 and TESS discoveries using this observing mode. In particular, NGTS is well-suited to the measurement of shallow transits of bright targets. This is particularly important to improve orbital ephemerides of relatively long-period planets, where only a small number of transits are observed from space.
- [39] arXiv:2002.05602 [pdf, ps, other]
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Title: Phenomenological model explaining Hubble Tension originAuthors: G.S. Bisnovatyi-KoganComments: 13 pagesSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
One of the problem revealed recently in cosmology is a so-called Hubble tension (HT), which is the difference between values of the present Hubble constant, measured by observation of the universe at redshift z smaller than 1, and by observations of a distant universe with CMB fluctuations originated at z about 1100. In this paper we suggest, that this discrepancy may be explained by deviation of the cosmological expansion from a simple Friedman model of a flat dusty universe during the period after recombination at z less than 1100, due to action of additional small component of a dark energy of a different origin.. We suppose, that a dark matter (DM) has a common origin with a small component of a dark energy (DEV). DE presently may have two components, one of which is the Einstein constant, and another, smaller component DEV comes from the remnants of a scalar fields responsible for inflation. Due to common origin and interconnections the ratio between DEV and DM densities is supposed to remain constant during, at least, the time after recombination. This part of the dark energy in not connected with the cosmological constant Lambda, but is defined by existence of scalar fields with a variable density. Taking into account the influence of DEV on the universe expansion we find the value of this ratio, which should remove the HT problem.
- [40] arXiv:2002.05611 [pdf, other]
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Title: Hydrogen ionization equilibrium in magnetic fieldsComments: 15 pages, 10 figures. Accepted for publication in Astronomy & AstrophysicsSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Atomic Physics (physics.atom-ph)
We assess the partition function and ionization degree of magnetized hydrogen atoms at thermodynamic equilibrium for a wide range of field intensities, $B\approx 10^5$-$10^{12}$~G. Evaluations include fitting formulae for an arbitrary number of binding energies, the coupling between the internal atomic structure and the center-of-mass motion across the magnetic field, and the formation of the so-called decentered states (bound states with the electron shifted from the Coulomb well). Non-ideal gas effects are treated within the occupational probability method. We also present general mathematical expressions for the bound state correspondence between the limits of zero-field and high-field. This let us evaluate the atomic partition function in a continuous way from the Zeeman perturbative regime to very strong fields. Results are shown for conditions found in atmospheres of magnetic white dwarf stars (MWDs), with temperatures $T\approx 5000$-$80000$~K and densities $\rho\approx 10^{-12}$-$10^{-3}$~g~cm$^3$. Our evaluations show a marked reduction of the gas ionization due to the magnetic field in the atmospheres of strong MWDs. We also found that decentered states could be present in the atmospheres of currently known hot MWDs, giving a significant contribution to the partition function in the strongest magnetized atmospheres.
- [41] arXiv:2002.05622 [pdf, other]
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Title: Minimizing the polarization leakage of geometric-phasecoronagraphs with multiple grating pattern combinationsComments: 23 pages, 15 figures, accepted for publication in PASPSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)
The design of liquid-crystal diffractive phase plate coronagraphs for ground-based and space-based high-contrast imaging systems is limited by the trade-off between spectral bandwidth and polarization leakage. We demonstrate that by combining phase patterns with a polarization grating (PG) pattern directly followed by one or several separate PGs, we can suppress the polarization leakage terms by additional orders of magnitude by diffracting them out of the beam. \textcolor{black}{Using two PGs composed of a single-layer liquid crystal structure in the lab, we demonstrate a leakage suppression of more than an order of magnitude over a bandwidth of 133 nm centered around 532 nm. At this center wavelength we measure a leakage suppression of three orders of magnitude.} Furthermore, simulations indicate that a combination of two multi-layered liquid-crystal PGs can suppress leakage to $<10^{-5}$ for 1-2.5 $\mu$m and $<10^{-10}$ for 650-800 nm. We introduce multi-grating solutions with three or more gratings that can be designed to have no separation of the two circular polarization states, and offer even deeper suppression of polarization leakage. We present simulations of a triple-grating solution that has $<10^{-10}$ leakage on the first Airy ring from 450 nm to 800 nm. We apply the double-grating concept to the Vector-Vortex coronagraph of charge 4, and demonstrate in the lab that polarization leakage no longer limits the on-axis suppression for ground-based contrast levels. Lastly, we report on the successful installation and first-light results of a double-grating vector Apodizing Phase Plate pupil-plane coronagraph installed at the Large Binocular Telescope. We discuss the implications of these new coronagraph architectures for high-contrast imaging systems on the ground and in space.
- [42] arXiv:2002.05626 [pdf, other]
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Title: Multipole expansion for HI intensity mapping experiments: simulations and modellingComments: 21 pages, 14 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
We present a framework and an open-source python toolkit to analyse the 2-point statistics of 3D fluctuations in the context of HI intensity maps using the multipole expansion formalism. We include simulations of the cosmological HI signal using N-body and log-normal methods, foregrounds and their removal, as well as instrumental effects. Using these simulations and analytical modelling, we investigate the impact of foreground cleaning and the instrumental beam on the power spectrum multipoles as well as on the Fourier space clustering wedges. We find that both the instrumental beam and the foreground removal can produce a quadrupole (and a hexadecapole) signal, and demonstrate the importance of controlling and accurately modelling these effects for precision radio cosmology. We conclude that these effects can be modelled with reasonable accuracy using our multipole expansion technique. We also perform an MCMC analysis to showcase the effect of foreground cleaning on the estimation of the HI abundance and bias parameters. The accompanying python toolkit is available at https://github.com/IntensityTools/MultipoleExpansion, and includes an interactive suite of examples to aid new users.
- [43] arXiv:2002.05656 [pdf, other]
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Title: Dynamics of Planetary Systems Within Star Clusters: Aspects of the Solar System's Early EvolutionComments: 30 pages, 16 figures, published in The Astronomical JournalJournal-ref: The Astronomical Journal (2020) volume 159, number 3Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)
Most planetary systems -- including our own -- are born within stellar clusters, where interactions with neighboring stars can help shape the system architecture. This paper develops an orbit-averaged formalism to characterize the cluster's mean-field effects as well as the physics of long-period stellar encounters. Our secular approach allows for an analytic description of the dynamical consequences of the cluster environment on its constituent planetary systems. We analyze special cases of the resulting Hamiltonian, corresponding to eccentricity evolution driven by planar encounters, as well as hyperbolic perturbations upon dissipative disks. We subsequently apply our results to the early evolution of our solar system, where the cluster's collective potential perturbs the solar system's plane, and stellar encounters act to increase the velocity dispersion of the Kuiper belt. Our results are two-fold: first, we find that cluster effects can alter the mean plane of the solar system by $\lesssim1\deg$, and are thus insufficient to explain the $\psi\approx6\deg$ obliquity of the sun. Second, we delineate the extent to which stellar flybys excite the orbital dispersion of the cold classical Kuiper belt, and show that while stellar flybys may grow the cold belt's inclination by the observed amount, the resulting distribution is incompatible with the data. Correspondingly, our calculations place an upper limit on the product of the stellar number density and residence time of the sun in its birth cluster, $\eta\,\tau\lesssim2\times10^4\,$Myr/pc$^3$.
- [44] arXiv:2002.05662 [pdf, other]
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Title: Spots, flares, accretion, and obscuration in the pre-main sequence binary DQ TauComments: 2 pages, 1 figure, published in "Origins: From the Protosun to the First Steps of Life. Proceedings of the International Astronomical Union, Volume 345"Journal-ref: Origins: From the Protosun to the First Steps of Life. Proceedings of the International Astronomical Union, Volume 345, pp. 314-315 (2020)Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP)
DQ Tau is a young low-mass spectroscopic binary, consisting of two almost equal-mass stars on a 15.8 day period surrounded by a circumbinary disk. We analyzed DQ Tau's light curves obtained by Kepler K2, the Spitzer Space Telescope, and ground-based facilities. We observed variability phenomena, including rotational modulation by stellar spots, energetic stellar flares, brightening events around periastron due to increased accretion, and short dips due to temporary circumstellar obscuration. The study on DQ Tau will help in discovering and understanding the formation and evolution of other real-world examples of "Tatooine-like" systems. This is especially important because more and more evidence points to the possibility that all Sun-like stars were born in binary or multiple systems that broke up later due to dynamical interactions.
- [45] arXiv:2002.05669 [pdf, other]
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Title: Optical suppression of tilt-to-length coupling in the LISA long-arm interferometerAuthors: M Chwalla, K Danzmann, M Dovale Álvarez, J J Esteban Delgado, G Fernández Barranco, E Fitzsimons, O Gerberding, G Heinzel, C J Killow, M Lieser, M Perreur-Lloyd, D I Robertson, S Schuster, T S Schwarze, M Tröbs, G Wanner, H Ward, M ZwetzComments: 11 pages, 10 figuresSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Optics (physics.optics)
The arm length and the isolation in space enable LISA to probe for signals unattainable on ground, opening a window to the sub-Hz gravitational-wave universe. The coupling of unavoidable angular spacecraft jitter into the longitudinal displacement measurement, an effect known as tilt-to-length (TTL) coupling, is critical for realizing the required sensitivity of picometer$/\sqrt{\rm{Hz}}$. An ultra-stable interferometer testbed has been developed in order to investigate this issue and validate mitigation strategies in a setup representative of the LISA long-arm interferometer. We demonstrate a reduction of TTL coupling between a flat-top beam and a Gaussian beam via introducing two- and four-lens imaging systems. TTL coupling factors below $\pm 25\,\mu$m/rad for beam tilts within $\pm 300\,\mu$rad are obtained by careful optimization of the system. Moreover we show that the additional TTL coupling due to lateral alignment errors of elements of the imaging system can be compensated by introducing lateral shifts of the detector, and vice versa. These findings help validate the suitability of this noise-reduction technique for the LISA long-arm interferometer.
- [46] arXiv:2002.05717 [pdf, other]
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Title: The cross correlation of the ABS and ACT mapsAuthors: Zack Li, Sigurd Naess, Simone Aiola, David Alonso, John W. Appel, J. Richard Bond, Erminia Calabrese, Steve K. Choi, Kevin T. Crowley, Thomas Essinger-Hileman, Shannon M. Duff, Joanna Dunkley, J. W. Fowler, Patricio Gallardo, Shuay-Pwu Patty Ho, Johannes Hubmayr, Akito Kusaka, Thibaut Louis, Mathew S. Madhavacheril, Jeffrey McMahon, Federico Nati, Michael D. Niemack, Lyman Page, Lucas Parker, Bruce Partridge, Maria Salatino, Jonathan L. Sievers, Cristóbal Sifón, Sara M. Simon, Suzanne T. Staggs, Emilie Storer, Edward J. WollackComments: 7 pages, 5 figures. For an interactive demonstration of the methods, see this https URLSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
One of the most important checks for systematic errors in CMB studies is the cross correlation of maps made by independent experiments. In this paper we report on the cross correlation between maps from the Atacama B-mode Search (ABS) and Atacama Cosmology Telescope (ACT) experiments in both temperature and polarization. These completely different measurements have a clear correlation with each other and with the Planck satellite in both the EE and TE spectra at $\ell<400$ over the roughly $1100$ deg$^2$ common to all three. The TB, EB, and BB cross spectra are consistent with noise. Exploiting such cross-correlations will be important for future experiments operating in Chile that aim to probe the $30<\ell<8,000$ range.
Cross-lists for Fri, 14 Feb 20
- [47] arXiv:2002.05161 (cross-list from gr-qc) [pdf, ps, other]
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Title: Giant low-surface-brightness dwarf galaxy as a test bench for MOdified GravityAuthors: Ivan de MartinoComments: 4 pages; 1 Figure; 1 Table. Accepted for publication on MNRASSubjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); Astrophysics of Galaxies (astro-ph.GA)
The lack of detection of supersymmetric particles is leading to look at alternative avenues for explaining dark matter's effects. Among them, modified theories of gravity may play an important role accounting even for both dark components needed in the standard cosmological model. Scalar-Tensor-Vector Gravity theory has been proposed to resolve the dark matter puzzle. Such a modified gravity model introduces, in its weak field limit, a Yukawa-like correction to the Newtonian potential, and is capable to explain most of the phenomenology related to dark matter at scale of galaxies and galaxy clusters. Nevertheless, some inconsistencies appears when studying systems that are supposed to be dark matter dominated such as dwarf galaxies. In this sense Antlia II, an extremely diffuse galaxy which has been recently discovered in {\em Gaia}'s second data release, may serve to probe the aforementioned theory against the need for invoking dark matter. Our analysis shows several inconsistencies and leads to argue that MOdified Gravity may not be able to shed light on the intriguing nature of dark matter.
- [48] arXiv:2002.05170 (cross-list from hep-ph) [pdf, other]
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Title: WIMP Cogenesis for Asymmetric Dark Matter and the Baryon AsymmetryComments: 21 pages, 16 figures, 1 appendixSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Experiment (hep-ex); High Energy Physics - Theory (hep-th)
We propose a new mechanism where asymmetric dark matter (ADM) and the baryon asymmetry are both generated in the same decay chain of a metastable weakly interacting massive particle (WIMP) after its thermal freeze-out. Dark matter and baryons are connected by a generalized baryon number that is conserved, while the DM asymmetry and baryon asymmetry compensate each other. This unified framework addresses the DM-baryon coincidence while inheriting the merit of the conventional WIMP miracle in predicting relic abundances of matter. Examples of renormalizable models realizing this scenario are presented. These models generically predict ADM with sub-GeV to GeV-scale mass that interacts with Standard Model quarks or leptons, thus rendering potential signatures at direct detection experiments sensitive to low mass DM. Other interesting phenomenological predictions are also discussed, including: LHC signatures of new intermediate particles with color or electroweak charge and DM induced nucleon decay; the long-lived WIMP may be within reach of future high energy collider experiments.
- [49] arXiv:2002.05177 (cross-list from gr-qc) [pdf, other]
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Title: Coherent Gravitational Waveforms and Memory from Cosmic String LoopsSubjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)
We construct, for the first time, the time-domain gravitational wave strain waveform from the collapse of a strongly gravitating Abelian Higgs cosmic string loop in full general relativity. We show that the strain exhibits a large memory effect during merger, ending with a burst and the characteristic ringdown as a black hole is formed. Furthermore, we investigate the waveform and energy emitted as a function of string width, loop radius and string tension $G\mu$. We find that the mass normalized gravitational wave energy displays a strong dependence on the inverse of the string tension $E_{\mathrm{GW}}/M_0\propto 1/G\mu$, with $E_{\mathrm{GW}}/M_0 \sim {\cal O}(1)\%$ at the percent level, for the regime where $G\mu\gtrsim10^{-3}$. Conversely, we show that the efficiency is only weakly dependent on the initial string width and initial loop radii. Using these results, we argue that gravitational wave production is dominated by kinematical instead of geometrical considerations.
- [50] arXiv:2002.05429 (cross-list from nucl-th) [pdf, other]
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Title: Coexistence phase of $^{1}S_{0}$ and $^{3}P_{2}$ superfluids in neutron starsComments: 14 pages, 3 figuresSubjects: Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); Superconductivity (cond-mat.supr-con)
In neutron star matter, there exist $^{1}S_{0}$ superfluids in lower density in the crust while $^{3}P_{2}$ superfluids are believed to exist at higher density deep inside the core. In the latter, depending on the temperature and magnetic field, either uniaxial nematic (UN) phase, D$_{2}$-biaxial nematic (D$_{2}$-BN) phase, or D$_{4}$-biaxial nematic (D$_{4}$-BN) phase appears. In this paper, we discuss a mixture of the $^{1}S_{0}$ and $^{3}P_{2}$ superfluids and find their coexistence. Adopting the loop expansion and the weak-coupling approximation for the interaction between two neutrons, we obtain the Ginzburg-Landau (GL) free energy in which both of the $^{1}S_{0}$ and $^{3}P_{2}$ condensates are taken into account by including the coupling terms between them. We analyze the GL free energy and obtain the phase diagram for the temperature and magnetic field. We find that the $^{1}S_{0}$ superfluid excludes the $^{3}P_{2}$ superfluid completely in the absence of magnetic field, they can coexist for weak magnetic fields, and the $^{1}S_{0}$ superfluid is expelled by the $^{3}P_{2}$ superfluid at strong magnetic fields, thereby proving the robustness of $^{3}P_{2}$ superfluid against the magnetic field. We further show that the D$_{4}$-BN phase covers the whole region of the $^{3}P_{2}$ superfluidity as a result of the coupling term, in contrast to the case of a pure $^{3}P_{2}$ superfluid studied before in which the D$_{4}$-BN phase is realized only under strong magnetic fields. Thus, the D$_{4}$-BN phase is topologically most interesting phase, e.g., admitting half-quantized non-Abelian vortices relevant not only in magnetars but also in ordinary neutron stars.
- [51] arXiv:2002.05668 (cross-list from gr-qc) [pdf, other]
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Title: Gravitational-Wave Implications for the Parity Symmetry of Gravity at GeV ScaleComments: 5 pages, 4 figures, posterior files available in this https URLSubjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Phenomenology (hep-ph)
Gravitational waves generated by the coalescence of compact binary open a new window to test the fundamental properties of gravity in the strong-field and dynamical regime. In this work, we focus on the parity symmetry of gravity which, if broken, can leave imprints on the waveform of gravitational wave. We construct generalized waveforms with amplitude and velocity birefringence due to parity violation in the effect field theory formalism, then analyze the open data of the ten binary black-hole merger events and the two binary neutron-star merger events detected by LIGO and Virgo collaboration. We do not find any signatures of violation of gravitational parity conservation, thereby setting the lower bound of the parity-violating energy scale to be $0.07$ GeV. This presents the first observational evidence of the parity conservation of gravity at high energy scale, about 17 orders of magnitude tighter than the constraints from the Solar system tests and binary pulsar observation. The third-generation gravitational-wave detector is capable of probing the parity-violating energy scale at $\mathcal{O}(10^2)$ GeV.
Replacements for Fri, 14 Feb 20
- [52] arXiv:1708.07805 (replaced) [pdf, other]
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Title: Dimensional Reduction of Direct Statistical SimulationComments: 17 pages and 11 figures. Corrections, improved figures, and new section on "Continuation in Parameter Space."Subjects: Fluid Dynamics (physics.flu-dyn); Earth and Planetary Astrophysics (astro-ph.EP); Statistical Mechanics (cond-mat.stat-mech); Atmospheric and Oceanic Physics (physics.ao-ph)
- [53] arXiv:1811.03638 (replaced) [pdf, other]
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Title: Quasar Accretion Disk Sizes from Continuum Reverberation Mapping in the DES Standard Star FieldsAuthors: Zhefu Yu, Paul Martini, T. M. Davis, R. A. Gruendl, J. K. Hoormann, C. S. Kochanek, C. Lidman, D. Mudd, B. M. Peterson, W. Wester, S. Allam, J. Annis, J. Asorey, S. Avila, M. Banerji, E. Bertin, D. Brooks, E. Buckley-Geer, J. Calcino, A. Carnero Rosell, D. Carollo, M. Carrasco Kind, J. Carretero, C. E. Cunha, C. B. D'Andrea, L. N. da Costa, J. De Vicente, S. Desai, H. T. Diehl, P. Doel, T. F. Eifler, B. Flaugher, P. Fosalba, J. Frieman, J. García-Bellido, E. Gaztanaga, K. Glazebrook, D. Gruen, J. Gschwend, G. Gutierrez, W. G. Hartley, S. R. Hinton, D. L. Hollowood, K. Honscheid, B. Hoyle, D. J. James, A. G. Kim, E. Krause, K. Kuehn, N. Kuropatkin, G. F. Lewis, M. Lima, E. Macaulay, M. A. G. Maia, J. L. Marshall, F. Menanteau, R. Miquel, A. Möller, A. A. Plazas, A. K. Romer, et al. (15 additional authors not shown)Comments: 33 pages, 24 figuresJournal-ref: The Astrophysical Journal Supplement Series, 246:16 (27pp), 2020Subjects: Astrophysics of Galaxies (astro-ph.GA)
- [54] arXiv:1902.05081 (replaced) [pdf, ps, other]
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Title: Using Commensurabilities and Orbit Structure to Understand Barred Galaxy EvolutionComments: Submitted to MNRAS, comments welcomeSubjects: Astrophysics of Galaxies (astro-ph.GA)
- [55] arXiv:1903.03118 (replaced) [pdf, other]
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Title: New substellar discoveries from Kepler and K2: Is there a brown dwarf desert?Comments: 15 pages, 6 figures, 11 tables, accepted to AJSubjects: Earth and Planetary Astrophysics (astro-ph.EP)
- [56] arXiv:1907.05735 (replaced) [pdf, other]
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Title: On the Origin of Dust in Galaxy Clusters at Low to Intermediate RedshiftComments: MNRAS. Accepted on Feb 11th, 2020. 13 pages, 4 figuresSubjects: Astrophysics of Galaxies (astro-ph.GA)
- [57] arXiv:1907.07870 (replaced) [pdf, other]
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Title: New constraints on the mass bias of galaxy clusters from the power spectra of the thermal Sunyaev-Zeldovich effect and cosmic shearComments: 8 pages, 3 figures, PASJ acceptedSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [58] arXiv:1909.01457 (replaced) [pdf, other]
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Title: Freeze-in Production of Dark Matter Prior to Early Matter DominationComments: 15 pages, 7 figures, updated to match version accepted for publication in Phys. Rev. DSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)
- [59] arXiv:1910.00407 (replaced) [pdf, other]
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Title: Effective spin distribution of black hole mergers in triplesComments: 13 pages, 8 figures, 2 tables, accepted by MNRAS. arXiv admin note: text overlap with arXiv:1907.08614Subjects: Astrophysics of Galaxies (astro-ph.GA); High Energy Astrophysical Phenomena (astro-ph.HE)
- [60] arXiv:1910.01638 (replaced) [pdf, ps, other]
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Title: Particle and entropy production in the Running Vacuum UniverseComments: Gen. Rel. Grav. 52 (2020) no.2, 17 (this https URL)Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
- [61] arXiv:1910.08213 (replaced) [pdf]
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Title: Gravitational wave stochastic background from cosmological particle decayAuthors: Bruce AllenComments: Final published version (Open Access)Journal-ref: Phys. Rev. Research 2, 012034 (2020)Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Astrophysical Phenomena (astro-ph.HE)
- [62] arXiv:1910.09853 (replaced) [pdf, other]
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Title: Non-minimal dark sector physics and cosmological tensionsComments: 19 pages, 5 figures, added Bayesian evidence computation and further discussions. Version accepted for publication in PRDSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)
- [63] arXiv:1911.01530 (replaced) [pdf, other]
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Title: The effects of disk self-gravity and radiative cooling on the formation of gaps and spirals by young planetsComments: 21 pages, 15 figures, accepted by MNRASSubjects: Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)
- [64] arXiv:1911.10078 (replaced) [pdf, other]
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Title: Probing a cosmic axion-like particle background within the jets of active galactic nucleiComments: This work is prepared for submission to JCAPSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
- [65] arXiv:1911.11480 (replaced) [pdf, other]
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Title: Mass Bias of Weak Lensing Shear-selected Galaxy Cluster SamplesComments: Submitted to ApJ; 17 pages, 11 figuresSubjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [66] arXiv:1912.02616 (replaced) [pdf, other]
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Title: Interstellar communication network. I. Overview and assumptionsAuthors: Michael HippkeComments: Update to match version published in AJJournal-ref: Astronomical Journal, Volume 159, Number 3, 2020Subjects: Popular Physics (physics.pop-ph); Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM); Solar and Stellar Astrophysics (astro-ph.SR)
- [67] arXiv:1912.06661 (replaced) [pdf, other]
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Title: A testable hidden-sector model for Dark Matter and neutrino massesComments: 38 pages, 5 figures. v2: Matches the published version, typos fixed, references addedJournal-ref: JHEP02 (2020) 068Subjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [68] arXiv:1912.06867 (replaced) [pdf, other]
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Title: Could star-planet magnetic interactions lead to planet migration and influence stellar rotation ?Authors: Jérémy Ahuir, Antoine Strugarek, Allan-Sacha Brun, Stéphane Mathis, Emeline Bolmont, Mansour Benbakoura, Victor Réville, Christophe Le Poncin-LafitteComments: 5 pages, 2 figures, to appear in the Proceedings of IAU Symposium No. 354 - Solar and Stellar Magnetic Fields: Origins and ManifestationsSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP)
- [69] arXiv:1912.06891 (replaced) [pdf, ps, other]
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Title: Strong lensing in multimessenger astronomy as a test of the equivalence principleAuthors: Olivier MinazzoliComments: 3 pages. Few improvements of the text in this new versionSubjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
- [70] arXiv:2001.04472 (replaced) [pdf, other]
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Title: Interacting galaxies in the IllustrisTNG simulations -- II: Star formation in the post-merger stageComments: accepted for publication in MNRASSubjects: Astrophysics of Galaxies (astro-ph.GA)
- [71] arXiv:2001.09999 (replaced) [pdf, other]
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Title: The BUFFALO HST SurveyAuthors: Charles L. Steinhardt, Mathilde Jauzac, Ana Acebron, Hakim Atek, Peter Capak, Iary Davidzon, Dominique Eckert, David Harvey, Anton M. Koekemoer, Claudia D.P. Lagos, Guillaume Mahler, Mireia Montes, Anna Niemiec, Mario Nonino, P. A. Oesch, Johan Richard, Steven A. Rodney, Matthieu Schaller, Keren Sharon, Louis-Gregory Strolger, Joseph Allingham, Adam Amara, Yannick Bah'e, Celine Boehm, Sownak Bose, Rychard J. Bouwens, Larry D. Bradley, Gabriel Brammer, Tom Broadhurst, Rodrigo Canas, Renyue Cen, Benjamin Clement, Douglas Clowe, Dan Coe, Thomas Connor, Behnam Darvish, Jose M. Diego, Harald Ebeling, A. C. Edge, Eiichi Egami, Stefano Ettori, Andreas L. Faisst, Brenda Frye, Lukas J. Furtak, C. Gomez-Guijarro, J. D. Remolina Gonzalez, Anthony Gonzalez, Or Graur, Daniel Gruen, David Harvey, et al. (45 additional authors not shown)Comments: Accepted ApJS; MAST archive will be live concurrent with publicationSubjects: Astrophysics of Galaxies (astro-ph.GA)
- [72] arXiv:2001.10275 (replaced) [pdf, other]
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Title: Periodic activity from a fast radio burst sourceAuthors: The CHIME/FRB Collaboration, M. Amiri, B. C. Andersen, K. M. Bandura, M. Bhardwaj, P. J. Boyle, C. Brar, P. Chawla, T. Chen, J. F. Cliche, D. Cubranic, M. Deng, N. T. Denman, M. Dobbs, F. Q. Dong, M. Fandino, E. Fonseca, B. M. Gaensler, U. Giri, D. C. Good, M. Halpern, J. W. T. Hessels, A. S. Hill, C. Höfer, A. Josephy, J. W. Kania, R. Karuppusamy, V. M. Kaspi, A. Keimpema, F. Kirsten, T. L. Landecker, D. A. Lang, C. Leung, D. Z. Li, H. -H. Lin, B. Marcote, K. W. Masui, R. Mckinven, J. Mena-Parra, M. Merryfield, D. Michilli, N. Milutinovic, A. Mirhosseini, A. Naidu, L. B. Newburgh, C. Ng, K. Nimmo, Z. Paragi, C. Patel, U. -L. Pen, T. Pinsonneault-Marotte, Z. Pleunis, M. Rafiei-Ravandi, M. Rahman, S. M. Ransom, A. Renard, P. Sanghavi, P. Scholz, J. R. Shaw, K. Shin, S. R. Siegel, S. Singh, et al. (11 additional authors not shown)Comments: Extension of discussion to include a possible aliasing effectSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
- [73] arXiv:2002.04119 (replaced) [pdf, other]
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Title: A decade of multi-wavelength observations of the TeV blazar 1ES 1215+303: Extreme shift of the synchrotron peak frequency and long-term optical-gamma-ray flux increaseAuthors: Janeth Valverde, Deirdre Horan, Denis Bernard, Stephen Fegan (Fermi-LAT collaboration), A. U. Abeysekara, A. Archer, W. Benbow, R. Bird, A. Brill, R. Brose, M. Buchovecky, J. H. Buckley, J. L. Christiansen, W. Cui, A. Falcone, Q. Feng, J. P. Finley, L. Fortson, A. Furniss, A. Gent, G. H. Gillanders, C. Giuri, O. Gueta, D. Hanna, T. Hassan, O. Hervet, J. Holder, G. Hughes, T. B. Humensky, P. Kaaret, N. Kelley-Hoskins, M. Kertzman, D. Kieda, M. Krause, F. Krennrich, M. J. Lang, G. Maier, P. Moriarty, R. Mukherjee, D. Nieto, M. Nievas-Rosillo, S. O'Brien, R. A. Ong, A. N. Otte, N. Park, A. Petrashyk, K. Pfrang, A. Pichel, M. Pohl, R. R. Prado, E. Pueschel, J. Quinn, K. Ragan, P. T. Reynolds, D. Ribeiro, G. T. Richards, E. Roache, I. Sadeh, M. Santander, S. S. Scott, G. H. Sembroski, K. Shahinyan, et al. (27 additional authors not shown)Comments: Accepted for publication in the Astrophysical JournalSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
- [74] arXiv:2002.04468 (replaced) [pdf, other]
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Title: Consistent perturbative modeling of pseudo-Newtonian core-collapse supernova simulationsAuthors: John Ryan Westernacher-SchneiderComments: 11 pages, 9 figures, 2 tables. Journal submission will be delayed to allow for comments. v2: Added acknowledgementSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
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