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New submissions for Wed, 8 Jan 20

[1]  arXiv:2001.01724 [pdf]

Title: Updated design of the CMB polarization experiment satellite LiteBIRD

Authors: H. Sugai, P. A. R. Ade, Y. Akiba, D. Alonso, K. Arnold, J. Aumont, J. Austermann, C. Baccigalupi, A. J. Banday, R. Banerji, R. B. Barreiro, S. Basak, J. Beall, S. Beckman, M. Bersanelli, J. Borrill, F. Boulanger, M. L. Brown, M. Bucher, A. Buzzelli, E. Calabrese, F. J. Casas, A. Challinor, V. Chan, Y. Chinone, J.-F. Cliche, F. Columbro, A. Cukierman, D. Curtis, P. Danto, P. de Bernardis, T. de Haan, M. De Petris, C. Dickinson, M. Dobbs, T. Dotani, L. Duband, A. Ducout, S. Duff, A. Duivenvoorden, J.-M. Duval, K. Ebisawa, T. Elleflot, H. Enokida, H. K. Eriksen, J. Errard, T. Essinger-Hileman, F. Finelli, R. Flauger, C. Franceschet, U. Fuskeland, K. Ganga, J.-R. Gao, R. Génova-Santos, T. Ghigna, A. Gomez, M. L. Gradziel, J. Grain, F. Grupp, A. Gruppuso, J. E. Gudmundsson, N. W. Halverson, et al. (159 additional authors not shown)

Comments: Journal of Low Temperature Physics, in press

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)

Recent developments of transition-edge sensors (TESs), based on extensive experience in ground-based experiments, have been making the sensor techniques mature enough for their application on future satellite CMB polarization experiments. LiteBIRD is in the most advanced phase among such future satellites, targeting its launch in Japanese Fiscal Year 2027 (2027FY) with JAXA's H3 rocket. It will accommodate more than 4000 TESs in focal planes of reflective low-frequency and refractive medium-and-high-frequency telescopes in order to detect a signature imprinted on the cosmic microwave background (CMB) by the primordial gravitational waves predicted in cosmic inflation. The total wide frequency coverage between 34GHz and 448GHz enables us to extract such weak spiral polarization patterns through the precise subtraction of our Galaxy's foreground emission by using spectral differences among CMB and foreground signals. Telescopes are cooled down to 5Kelvin for suppressing thermal noise and contain polarization modulators with transmissive half-wave plates at individual apertures for separating sky polarization signals from artificial polarization and for mitigating from instrumental 1/f noise. Passive cooling by using V-grooves supports active cooling with mechanical coolers as well as adiabatic demagnetization refrigerators. Sky observations from the second Sun-Earth Lagrangian point, L2, are planned for three years. An international collaboration between Japan, USA, Canada, and Europe is sharing various roles. In May 2019, the Institute of Space and Astronautical Science (ISAS), JAXA selected LiteBIRD as the strategic large mission No. 2.

[2]  arXiv:2001.01728 [pdf, other]

Title: The low-surface-brightness Universe: a new frontier in the study of galaxy evolution

Authors: Sugata Kaviraj

Comments: Invited talk, to appear in the Proceedings of the IAU Symposium 355, 'The Realm of the Low-surface-brightness Universe', 12 pages, 7 figures

Subjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)

New and forthcoming deep-wide surveys, from instruments like the HSC, LSST and EUCLID, are poised to revolutionize our understanding of galaxy evolution, by revealing aspects of galaxies that are largely invisible in past wide-area datasets. These surveys will open up the realm of low-surface-brightness (LSB) and dwarf galaxies -- which dominate the galaxy number density -- for the first time at cosmological distances. They will also reveal key, unexplored LSB structures which strongly constrain our structure-formation paradigm, such as merger-induced tidal features and intra-cluster light. However, exploitation of these revolutionary new datasets will require us to address several data-analysis challenges. Data-processing pipelines will have to preserve LSB structures, which are susceptible to sky over-subtraction. Analysis of the prodigious data volumes will require machine-learning (in particular unsupervised techniques), to augment or even replace traditional methods. Cosmological simulations, which are essential for a statistical understanding of the physics of galaxy evolution, will require mass and spatial resolutions that are high enough to resolve LSB/dwarf galaxies and LSB structures. And finally, estimation of physical properties (e.g. stellar masses and star formation rates) will require reliable redshift information. Since it is unlikely that even next-generation spectrographs will provide complete spectral coverage in the LSB/dwarf regime outside the nearby Universe, photometric redshifts may drive the science from these datasets. It is necessary, therefore, that the accuracy of these redshifts is good enough (e.g. < 10 per cent) to enable statistical studies in the LSB/dwarf regime. I outline the tremendous discovery potential of new/forthcoming deep-wide surveys and describe techniques which will enable us to solve the data-analysis challenges outlined above. (Abridged)

[3]  arXiv:2001.01730 [pdf, ps, other]

Title: Upper Limit on the Dissipation of Gravitational Waves in Gravitationally Bound Systems

Authors: Abraham Loeb (Harvard)

Comments: 4 pages, submitted to The Astrophysical Journal Letters

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)

It is shown that a gravitationally bound system with a one-dimensional velocity dispersion sigma can at most dissipate a fraction ~36(sigma/c)^3 of the gravitational wave energy propagating through it. The limit is saturated for particles with a mean-free-path equal to the size of the system, such as hot protons in galaxy clusters, strongly-interacting dark matter particles in halos, or massive black holes in clusters. Even for these systems, the dissipated fraction, <10^{-6}, does not degrade the use of gravitational waves as standard sirens for cosmology. In particular, the dissipation effect is smaller by a factor ~0.03(c/sigma)^2 than the peculiar velocity uncertainty of the source within its host dynamical system. The electromagnetic counterparts that result from the dissipation are too faint to be detectable at cosmological distances.

[4]  arXiv:2001.01731 [pdf, other]

Title: How stellar rotation shapes the colour magnitude diagram of the massive intermediate-age star cluster NGC 1846

Authors: Sebastian Kamann, Nate Bastian, Seth Gossage, Dietrich Baade, Ivan Cabrera-Ziri, Gary Da Costa, Selma E. de Mink, Cyril Georgy, Benjamin Giesers, Fabian Göttgens, Michael Hilker, Tim-Oliver Husser, Carmela Lardo, Søren Larsen, Dougal Mackey, Silvia Martocchia, Alessio Mucciarelli, Imants Platais, Martin M. Roth, Maurizio Salaris, Christopher Usher, David Yong

Comments: Accepted for publication in MNRAS, 15 pages, 10 figures

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)

We present a detailed study of stellar rotation in the massive 1.5 Gyr old cluster NGC 1846 in the Large Magellanic Cloud. Similar to other clusters at this age, NGC 1846 shows an extended main sequence turn-off (eMSTO), and previous photometric studies have suggested it could be bimodal. In this study, we use MUSE integral-field spectroscopy to measure the projected rotational velocities (vsini) of around 1400 stars across the eMSTO and along the upper main sequence of NGC 1846. We measure vsini values up to ~250 km/s and find a clear relation between the vsini of a star and its location across the eMSTO. Closer inspection of the distribution of rotation rates reveals evidence for a bimodal distribution, with the fast rotators centred around vsini = 140 km/s and the slow rotators centred around vsini = 60 km/s. We further observe a lack of fast rotating stars along the photometric binary sequence of NGC 1846, confirming results from the field that suggest that tidal interactions in binary systems can spin down stars. However, we do not detect a significant difference in the binary fractions of the fast and slowly rotating sub-populations. Finally, we report on the serendipitous discovery of a planetary nebula associated with NGC 1846.

[5]  arXiv:2001.01732 [pdf, ps, other]

Title: Correlating nonlinear time series and spectral properties of IGR J17091-3624: Is it similar to GRS 1915+105?

Authors: Oluwashina Adegoke (IISc), Banibrata Mukhopadhyay (IISc), Ranjeev Misra (IUCAA)

Comments: 10 pages including 5 figures and 5 tables; accepted for publication in MNRAS

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

We explore the nonlinear properties of IGR J17091-3624 in the line of the underlying behaviour for GRS 1915+105, following correlation integral method. We find that while the latter is known to reveal the combination of fractal (or even chaotic) and stochastic behaviours depending on its temporal class, the former mostly shows stochastic behaviour. Therefore, although several observations argue IGR J17091-3624 to be similar to GRS 1915+105 with common temporal classes between them, underlying nonlinear time series analyses offer differently. Nevertheless, the Poisson noise to $rms$ variation value for IGR J17091-3624 turns out to be high, arguing them to be Poisson noise dominated and hence may plausibly lead to suppression of the nonlinear character, if any. Indeed, it is a very faint source compared to GRS 1915+105. However, by increasing time bin some of the temporal classes of IGR J17091-3624 show deviation from stochasticity, indicating plausibility of higher fractal dimension. Along with spectral analysis, overall IGR J17091-3624 argues to reveal three different accretion classes: slim, Keplerian and advective accretion discs.

[6]  arXiv:2001.01734 [pdf, other]

Title: The properties of the interstellar medium of galaxies across time as traced by the neutral atomic carbon [CI]

Authors: Francesco Valentino (1 and 2), Georgios E. Magdis (1,2,3 and 4), Emanuele Daddi (5), Daizhong Liu (6), Manuel Aravena (7), Frederic Bournaud (5), Isabella Cortzen (1 and 2), Yu Gao (8), Shuowen Jin (9 and 10), Stephanie Juneau (11), Jeyhan S. Kartaltepe (12), Vasily Kokorev (1 and 2), Min-Young Lee (13 and 14), Suzanne C. Madden (5), Desika Narayanan (1 and 15), Gergo Popping (16), Annagrazia Puglisi (5) ((1) Cosmic Dawn Center, (2) Niels Bohr Institute - University of Copenhagen, (3) DTU Space - Technical University of Denmark, (4) National Observatory of Athens, (5) CEA Saclay, (6) MPIA Heidelberg, (7) Universidad Diego Portales, (8) Purple Mountain Observatory, (9) IAC, (10) Universidad de la Laguna, (11) NOAO, (12) Rochester Institute of Technology, (13) Korea Astronomy and Space Science Institute, (14) Max-Planck-Institut fur Radioastronomie, (15) University of Florida, (16) European Southern Observatory)

Comments: 20 pages + Appendix, accepted for publication in the Astrophysical Journal on Dec. 20th, 2019. The data compilation is available in the online version of the article

Subjects: Astrophysics of Galaxies (astro-ph.GA)

We report ALMA observations of the neutral atomic carbon transitions [CI] and multiple CO lines in a sample of $\sim30$ main sequence galaxies at $z\sim1$, including novel information on [CI](2-1) and CO(7-6) for 7 of such normal objects. We complement our observations with a collection of $>200$ galaxies with coverage of similar transitions, spanning the $z=0-4$ redshift interval and a variety of ambient conditions from local to high-redshift starbursts. We find systematic variations in the [CI]/IR and [CI]/high-$J$ ($J=7$) CO luminosity ratios among the various samples. We interpret these differences as increased dense molecular gas fractions and star formation efficiencies in the strongest high-redshift starbursts with respect to normal main sequence galaxies. We further report constant $L'_{\rm [CI]2-1}$/$L'_{\rm [CI]1-0}$ ratios across the galaxy populations and redshifts, suggesting that gas temperatures $T_{\rm exc}$ traced by [CI] do not strongly vary. We find only a mild correlation with $T_{\rm dust}$ and that, generally, $T_{\rm exc} \lesssim T_{\rm dust}$. We fit the line ratios with classical PDR models, retrieving consistently larger densities and intensities of the UV radiation fields in submm galaxies than in main sequence and local objects. However, these simple models fall short in representing the complexity of a multiphase interstellar medium and should be treated with caution. Finally, we compare our observations with the Santa Cruz semi-analytical model of galaxy evolution, recently extended to simulate submm emission. While we confirm the success in reproducing the CO lines, we find systematically larger [CI] luminosities at fixed IR luminosity than predicted theoretically. This highlights the necessity of improving our understanding of the mechanisms regulating the [CI] emission on galactic scales. We release our data compilation to the community.

[7]  arXiv:2001.01737 [pdf, other]

Title: A search for IceCube events in the direction of ANITA neutrino candidates

Authors: IceCube Collaboration: M. G. Aartsen, M. Ackermann, J. Adams, J. A. Aguilar, M. Ahlers, M. Ahrens, C. Alispach, K. Andeen, T. Anderson, I. Ansseau, G. Anton, C. Argüelles, J. Auffenberg, S. Axani, P. Backes, H. Bagherpour, X. Bai, A. Balagopal V., A. Barbano, S. W. Barwick, B. Bastian, V. Baum, S. Baur, R. Bay, J. J. Beatty, K.-H. Becker, J. Becker Tjus, S. BenZvi, D. Berley, E. Bernardini, D. Z. Besson, G. Binder, D. Bindig, E. Blaufuss, S. Blot, C. Bohm, S. Böser, O. Botner, J. Böttcher, E. Bourbeau, J. Bourbeau, F. Bradascio, J. Braun, S. Bron, J. Brostean-Kaiser, A. Burgman, J. Buscher, R. S. Busse, T. Carver, C. Chen, E. Cheung, D. Chirkin, S. Choi, K. Clark, L. Classen, A. Coleman, G. H. Collin, J. M. Conrad, P. Coppin, P. Correa, D. F. Cowen, R. Cross, P. Dave, C. De Clercq, et al. (296 additional authors not shown)

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Phenomenology (hep-ph)

During the first three flights of the Antarctic Impulsive Transient Antenna (ANITA) experiment, the collaboration detected several neutrino candidates. Two of these candidate events were consistent with an ultra-high-energy up-going air shower and compatible with a tau neutrino interpretation. A third neutrino candidate event was detected in a search for Askaryan radiation in the Antarctic ice, although it is also consistent with the background expectation. The inferred emergence angle of the first two events is in tension with IceCube and ANITA limits on isotropic cosmogenic neutrino fluxes. Here, we test the hypothesis that these events are astrophysical in origin, possibly caused by a point source in the reconstructed direction. Given that any ultra-high-energy tau neutrino flux traversing the Earth should be accompanied by a secondary flux in the TeV-PeV range, we search for these secondary counterparts in seven years of IceCube data using three complementary approaches. In the absence of any significant detection, we set upper limits on the neutrino flux from potential point sources. We compare these limits to ANITA's sensitivity in the same direction and show that an astrophysical explanation of these anomalous events under standard model assumptions is severely constrained regardless of source spectrum or time profile.

[8]  arXiv:2001.01739 [pdf, other]

Title: The manifestation of secondary halo bias on the galaxy population from IllustrisTNG300

Authors: Antonio D. Montero-Dorta, M. Celeste Artale, L. Raul Abramo, Beatriz Tucci, Nelson Padilla, Gabriela Sato-Polito, Iván Lacerna, Facundo Rodriguez, Raul E. Angulo

Comments: 16 pages, 10 figures, submitted to MNRAS

Subjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)

We use the improved IllustrisTNG300 magneto-hydrodynamical cosmological simulation to revisit the effect that secondary halo bias has on the clustering of the central galaxy population. With a side length of 205 $h^{-1}$Mpc and significant improvements on the sub-grid model with respect to the previous Illustris boxes, IllustrisTNG300 allows us to explore the dependencies of galaxy clustering over a large cosmological volume and wide halo-mass range. We show, at high statistical significance, that the halo assembly bias signal (i.e., the secondary dependence of halo bias on halo formation redshift) manifests itself on the clustering of the central galaxy population when this is split by stellar mass, colour, specific star formation rate, and surface density. A significant detection is also obtained for galaxy size: at fixed halo mass, larger central galaxies are more tightly clustered than smaller central galaxies in haloes of mass M$_{\rm vir} \lesssim 10^{12.5}$ $h^{-1}$M$_{\odot}$. This effect, however, seems to be uncorrelated with halo formation time, unlike the rest of the secondary dependencies analysed. We also explore the transmission of the halo spin bias signal, i.e., the secondary dependence of halo bias on halo spin. Although galaxy spin retains little information about the total spin of the halo, the correlation is enough to produce a significant galaxy spin bias signal. We discuss possible ways to probe the spin bias effects with observations.

[9]  arXiv:2001.01743 [pdf, other]

Title: The cosmological bulk flow in QCDM model: (In)consistency with $Λ CDM$

Authors: A. Salehi, M. Yarahmadi, S. Fathi

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc)

We study the bulk flow of the local universe using Type Ia supernova data by considering a class of cosmological model which is spatially flat,(FRW) space-times and contains cold dark matter and $Q$ component (QCDM models) of the fluid as a scalar field, with self interactions determined by a potential $V(Q)=V_{0}Exp(-\lambda Q)$ evolving in Universe. We use different cumulative redshift slices of the Union 2 catalogue. A maximum-likelihood analysis of peculiar velocities confirms that at low redshift $0.015 <z<0.1$, bulk flow is moving towards the $(l; b) = (302^{o}\pm20^{o}; 3^{o}\pm10^{o})$ direction with $v _{bulk} = 240\pm 25kms^{-1} $ velocity. This direction is aligned with direction of (SSC) and agreement with a number previous studies at $(1-\sigma)$, however for high redshift $0.1 <z<0.2$, we get $v _{bulk} = 1000\pm 25kms^{-1} $ towards the $(l; b) = (254^{+16^{o}}_{-14^{o}}; 6^{+7^{o}}_{-10^{o}})$. This indicates that for low redshift our results are approximately consistent with the $\Lambda CDM$ model with the latest WMAP best fit cosmological parameters however for high redshift they are in disagreement of $\Lambda CDM$ and support the results of previous studies such as Kashlinsky et. al, which report the large bulk flow for the Universe. We can conclude that, in $QCDM$ model, at small scales, fluctuations of the dark energy are damped and do not enter in the evolution equation for the perturbations in the pressureless matter, while at very large scales $(\sim > 100 h^{-1}Mpc)$, they leaving an imprint on the microwave background anisotropy.

[10]  arXiv:2001.01746 [pdf, other]

Title: The Orbital Histories of Magellanic Satellites Using Gaia DR2 Proper Motions

Authors: Ekta Patel, Nitya Kallivayalil, Nicolas Garavito-Camargo, Gurtina Besla, Daniel R. Weisz, Roeland P. van der Marel, Michael Boylan-Kolchin, Marcel S. Pawlowski, Facundo A. Gómez

Comments: 32 pages, 11 figures. Submitted to ApJ

Subjects: Astrophysics of Galaxies (astro-ph.GA)

With the release of Gaia DR2, it is now possible to measure the proper motions (PMs) of the lowest mass, ultra-faint satellites in the Milky Way's (MW) halo for the first time. Many of these faint satellites are posited to have been accreted as satellites of the Magellanic Clouds (MCs). Using their 6D phase space information, we calculate the orbital histories of 13 ultra-faint satellites and five classical satellites in a combined MW+LMC+SMC potential to determine which galaxies are dynamically associated with the LMC/SMC. We identify three classes of galaxies that have recently interacted with the MCs: i.) MW satellites on high-speed orbits that made a close approach ($< 100$ kpc) to the MCs $< 1$ Gyr ago (Sculptor 1, Tucana 3, Segue 1); ii.) short-term Magellanic satellites that have completed one recent, close pericentric passage (Reticulum 2, Phoenix 2); and iii.) long-term Magellanic satellites that have completed two consecutive recent, close passages (Carina 2, Carina 3, Horologium 1, Hydrus 1). Results are reported for a range of MW and LMC masses. Contrary to previous work, we find no dynamical association between Carina, Fornax, and the MCs. We find that Aquarius 2, Canes Venatici 2, Crater 2, Draco 1, Draco 2, Hydra 2, and Ursa Minor are not members of the Magellanic system. Finally, we determine that the addition of the SMC's gravitational potential affects the longevity of satellites as members of the Magellanic system (short-term versus long-term satellites), but it does not change the total population of Magellanic satellites.

[11]  arXiv:2001.01753 [pdf, other]

Title: A parsec-scale wobbling jet in the high-synchrotron peaked blazar PG 1553+113

Authors: Rocco Lico, J.Liu, M.Giroletti, M.Orienti, J.L.Gomez, B.G.Piner, N.R.MacDonald, F.D'Ammando, A.Fuentes

Comments: 11 pages, 7 images, 5 tables. Accepted for publication in Astronomy and Astrophysics

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Astrophysics of Galaxies (astro-ph.GA)

PG 1553+113 is the first blazar showing an approximately two-year quasi-periodic pattern in its gamma-ray light curve. Such quasi-periodicity might have a geometrical origin, possibly related to the precessing nature of the jet, or could be intrinsic to the source and related to pulsational accretion flow instabilities. By means of a ~2yr very long baseline array (VLBA) monitoring at 15, 24, and 43 GHz we investigate the source pc-scale properties during an entire cycle of gamma-ray activity in the period 2015-2017. In contrast to the well-defined periodicity in the gamma-ray emission, at radio frequencies no clear periodic pattern can be recognized. The jet position angle, constrained by means of the total intensity ridge line, varies across the different observing epochs in the range 40-60 deg. We also investigate the time evolution of the source polarization properties, including the rotation measure. The brightness temperature is found to decrease as the frequency increases with an intrinsic value of ~1.5 x 10^10 K and the estimated Doppler factor is ~1.4.

[12]  arXiv:2001.01754 [pdf, ps, other]

Title: Dead Zones of Classical Habitability in Stellar Binary Systems

Authors: Sarah Moorman, Zhaopeng Wang, Manfred Cuntz

Comments: Accepted by Astrophysics and Space Science; 17 pages, including 9 figures and 5 tables

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP)

Although habitability, defined as the general possibility of hosting life, is expected to occur under a broad range of conditions, the standard scenario to allow for habitable environments is often described through habitable zones (HZs). Previous work indicates that stellar binary systems typically possess S-type or P-type HZs, with the S-type HZs forming ring-type structures around the individual stars and P-type HZs forming similar structures around both stars, if considered a pair. However, depending on the stellar and orbital parameters of the system, typically, there are also regions within the systems outside of the HZs, referred to as dead zones (DZs). In this study, we will convey quantitative information on the width and location of DZs for various systems. The results will also depend on the definition of the stellar HZs as those are informed by the planetary climate models.

[13]  arXiv:2001.01757 [pdf, other]

Title: Statistics of CMB polarization angles

Authors: James Creswell, Nadia Dachlythra, Hao Liu, Pavel Naselsky, Per Rex Christensen

Comments: 14 pages, 6 figures

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)

We study the distribution functions of the CMB polarization angle $\psi$, focusing on the Planck 2018 CMB maps. We extend the model of Preece & Battye (2014) of Gaussian correlated $Q$ and $U$ Stokes parameters to allow nonzero means. When the variances of $Q$ and $U$ are equal and their covariance and means are zero, the polarization angle is uniformly distributed. Otherwise the uniform distribution will be modulated by harmonics with $2\psi$ and $4\psi$ phases. These modulations are visible in the Planck 2018 CMB maps. Furthermore, the mean value of $U$ is peculiar compared to the power spectrum.

[14]  arXiv:2001.01759 [pdf, other]

Title: A Rotation Rate for the Planetary-Mass Companion DH Tau b

Authors: Jerry W. Xuan, Marta L. Bryan, Heather A. Knutson, Brendan P. Bowler, Caroline V. Morley, Björn Benneke

Comments: Accepted to AJ

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)

DH Tau b is a young planetary-mass companion orbiting at a projected separation of 320 AU from its $\sim$2 Myr old host star DH Tau. With an estimated mass of $8-22$ $M_{\rm{Jup}}$ this object straddles the deuterium-burning limit, and might have formed via core or pebble accretion, disk instability, or molecular cloud fragmentation. To shed light on the formation history of DH Tau b, we obtain the first measurement of rotational line broadening for this object using high-resolution (R $\sim$25,000) near-infrared spectroscopy from Keck/NIRSPEC. We measure a projected rotational velocity ($v$sin$i$) of $9.6\pm0.7$ km/s, corresponding to a rotation rate that is between 9-15% of DH Tau b's predicted break-up speed. This low rotation rate is in good agreement with scenarios in which magnetic coupling between the companion and its circumplanetary disk during the late stages of accretion reduces angular momentum and regulates spin. We compare the rotation rate of DH Tau b to published values for other planetary-mass objects with masses between $0.3-20$ $M_{\rm{Jup}}$ and find no evidence of a correlation between mass and rotation rate in this mass regime. Finally, we search for evidence of individual molecules in DH Tau b's spectrum and find that it is dominated by CO and H$_2$O, with no evidence for the presence of CH$_4$. This agrees with expectations given DH Tau b's relatively high effective temperature ($\sim$2300 K).

[15]  arXiv:2001.01761 [pdf, other]

Title: GW190425: Observation of a Compact Binary Coalescence with Total Mass $\sim 3.4 M_{\odot}$

Authors: The LIGO Scientific Collaboration, the Virgo Collaboration: B. P. Abbott, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, K. Ackley, C. Adams, R. X. Adhikari, V. B. Adya, C. Affeldt, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, L. Aiello, A. Ain, P. Ajith, G. Allen, A. Allocca, M. A. Aloy, P. A. Altin, A. Amato, S. Anand, A. Ananyeva, S. B. Anderson, W. G. Anderson, S. V. Angelova, S. Antier, S. Appert, K. Arai, M. C. Araya, J. S. Areeda, M. Arène, N. Arnaud, S. M. Aronson, K. G. Arun, S. Ascenzi, G. Ashton, S. M. Aston, P. Astone, F. Aubin, P. Aufmuth, K. AultONeal, C. Austin, V. Avendano, A. Avila-Alvarez, S. Babak, P. Bacon, F. Badaracco, M. K. M. Bader, S. Bae, J. Baird, P. T. Baker, F. Baldaccini, G. Ballardin, S. W. Ballmer, A. Bals, S. Banagiri, J. C. Barayoga, C. Barbieri, et al. (1141 additional authors not shown)

Comments: 32 pages, 19 figures, submitted to ApJL

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc)

On 2019 April 25, the LIGO Livingston detector observed a compact binary coalescence with signal-to-noise ratio 12.9. The Virgo detector was also taking data that did not contribute to detection due to a low signal-to-noise ratio, but were used for subsequent parameter estimation. The 90% credible intervals for the component masses range from 1.12 to 2.52 $M_{\odot}$ (1.45 to 1.88 $M_{\odot}$ if we restrict the dimensionless component spin magnitudes to be smaller than 0.05). These mass parameters are consistent with the individual binary components being neutron stars. However, both the source-frame chirp mass $1.44^{+0.02}_{-0.02} M_{\odot}$ and the total mass $3.4^{+0.3}_{-0.1}\,M_{\odot}$ of this system are significantly larger than those of any other known binary neutron star system. The possibility that one or both binary components of the system are black holes cannot be ruled out from gravitational-wave data. We discuss possible origins of the system based on its inconsistency with the known Galactic binary neutron star population. Under the assumption that the signal was produced by a binary neutron star coalescence, the local rate of neutron star mergers is updated to $250-2810 \text{Gpc}^{-3}\text{yr}^{-1}$.

[16]  arXiv:2001.01763 [pdf, other]

Title: A study of the secondary cosmic $γ$ -ray flux in India during the Great American solar eclipse on 21$^{st}$ August 2017

Authors: S. Roy, S. Biswas, S. Das, S. K. Ghosh, S. Raha

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Instrumentation and Methods for Astrophysics (astro-ph.IM)

We present the results from the measurement of secondary cosmic gamma-ray flux using a NaI(Tl) scintillator detector during a total solar eclipse. The unique feature of this experiment is that it was carried out at a place where the solar eclipse was not observable. The total solar eclipse of August 21, 2017, was visible in most of the regions of North America during the day, whereas India, falling on the other half of the globe missed this particular eclipse. Our aim was to measure and examine if there are any variations in the secondary cosmic ray (SCR) flux at Kolkata, India due to the occurrence of the eclipse in America. Detailed experimental techniques used for this experiment are mentioned in this article. Method of data analysis and results are presented. We observe unexpected dehancement and enhancement of SCR flux in certain energy regions.

[17]  arXiv:2001.01787 [pdf, other]

Title: Primordial nucleosynthesis with varying fundamental constants: Improved constraints and a possible solution to the Lithium problem

Authors: M. T. Clara, C. J. A. P. Martins

Comments: 8 pages, 3 figures; Astronomy & Astrophysics Letters (in press)

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph)

Primordial nucleosynthesis is an observational cornerstone of the Hot Big Bang model and a sensitive probe of physics beyond the standard model. Its success has been limited by the so-called Lithium problem, for which many solutions have been proposed. We report on a self-consistent perturbative analysis of the effects of variations in nature's fundamental constants, which are unavoidable in most extensions of the standard model, on primordial nucleosynthesis, focusing on a broad class of Grand Unified Theory models. A statistical comparison between theoretical predictions and observational measurements of ${}^4$He, D, ${}^3$He and, ${}^7$Li consistently yields a preferred value of the fine-structure constant $\alpha$ at the nucleosynthesis epoch that is larger than the current laboratory one. The level of statistical significance and the preferred extent of variation depend on model assumptions but the former can be more than four standard deviations, while the latter is always compatible with constraints at lower redshifts. If Lithium is not included in the analysis, the preference for a variation of $\alpha$ is not statistically significant. The abundance of ${}^3$He is relatively insensitive to such variations. Our analysis highlights a viable and physically motivated solution to the Lithium problem, which warrants further study.

[18]  arXiv:2001.01804 [pdf, other]

Title: Boresight Alignment of DArk Matter Particle Explorer

Authors: Wei Jiang, Xiang Li, Kai-Kai Duan, Zhao-Qiang Shen, Zun-Lei Xu, Jing-Jing Zang, Shi-Jun Lei, Qiang Yuan

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)

The DArk Matter Particle Explorer (DAMPE) can measure $\gamma$-rays in the energy range from a few GeV to about 10 TeV. The direction of each $\gamma$-ray is reconstructed with respect to the reference system of the DAMPE payload. In this paper, we adopt a maximum likelihood method and use the $\gamma$-ray data centered around several bright point-like sources to measure and correct the angular deviation from the real celestial coordinate system, the so called ``boresight alignment'' of the DAMPE payload. As a check, we also estimate the boresight alignment for some sets of simulation data with artificial orientation and obtain consistent results. The time-dependent boresight alignment analysis does not show evidence for significant variation of the parameters.

[19]  arXiv:2001.01810 [pdf, other]

Title: The WAGGS project -- III. Discrepant mass-to-light ratios of Galactic globular clusters at high metallicity

Authors: H. Dalgleish, S. Kamann, C. Usher, H. Baumgardt, N. Bastian, J. Veitch-Michaelis, A. Bellini, S. Martocchia, G. S. Da Costa, D. Mackey, S. Bellstedt, N. Pastorello, P. Cerulo

Comments: 14 pages, 11 figures; accepted in MNRAS

Subjects: Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)

Observed mass-to-light ratios (M/L) of metal-rich globular clusters (GCs) disagree with theoretical predictions. This discrepancy is of fundamental importance since stellar population models provide the stellar masses that underpin most of extragalactic astronomy, near and far. We have derived radial velocities for 1,622 stars located in the centres of 59 Milky Way GCs - twelve of which have no previous kinematic information - using integral-field unit data from the WAGGS project. Using N-body models, we then determine dynamical masses and M/L ratios for the studied clusters. Our sample includes NGC 6528 and NGC 6553, which extend the metallicity range of GCs with measured M/L up to [Fe/H] ~ -0.1 dex. We find that metal-rich clusters have M/L more than two times lower than what is predicted by simple stellar population models. This confirms that the discrepant M/L-[Fe/H] relation remains a serious concern. We explore how our findings relate to previous observations, and the potential causes for the divergence, which we conclude is most likely due to dynamical effects.

[20]  arXiv:2001.01823 [pdf, ps, other]

Title: The High Time Resolution Universe Pulsar Survey -- XVI. Discovery and timing of 40 pulsars from the southern Galactic plane

Authors: A. D. Cameron, D. J. Champion, M. Bailes, V. Balakrishnan, E. D. Barr, C. G. Bassa, S. Bates, S. Bhandari, N. D. R. Bhat, M. Burgay, S. Burke-Spolaor, C. M. L. Flynn, A. Jameson, S. Johnston, M. J. Keith, M. Kramer, L. Levin, A. G. Lyne, C. Ng, E. Petroff, A. Possenti, D. A. Smith, B. W. Stappers, W. van Straten, C. Tiburzi, J. Wu

Comments: 28 pages, 9 figures, 13 tables

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

We present the results of processing an additional 44% of the High Time Resolution Universe South Low Latitude (HTRU-S LowLat) pulsar survey, the most sensitive blind pulsar survey of the southern Galactic plane to date. Our partially-coherent segmented acceleration search pipeline is designed to enable the discovery of pulsars in short, highly-accelerated orbits, while our 72-min integration lengths will allow us to discover pulsars at the lower end of the pulsar luminosity distribution. We report the discovery of 40 pulsars, including three millisecond pulsar-white dwarf binary systems (PSRs J1537-5312, J1547-5709 and J1618-4624), a black-widow binary system (PSR J1745-23) and a candidate black-widow binary system (PSR J1727-2951), a glitching pulsar (PSR J1706-4434), an eclipsing binary pulsar with a 1.5-yr orbital period (PSR J1653-45), and a pair of long spin-period binary pulsars which display either nulling or intermittent behaviour (PSRs J1812-15 and J1831-04). We show that the total population of 100 pulsars discovered in the HTRU-S LowLat survey to date represents both an older and lower-luminosity population, and indicates that we have yet to reach the bottom of the luminosity distribution function. We present evaluations of the performance of our search technique and of the overall yield of the survey, considering the 94% of the survey which we have processed to date. We show that our pulsar yield falls below earlier predictions by approximately 25% (especially in the case of millisecond pulsars), and discuss explanations for this discrepancy as well as future adaptations in RFI mitigation and searching techniques which may address these shortfalls.

[21]  arXiv:2001.01839 [pdf, other]

Title: Variability in the Massive Open Cluster NGC 1817 from K2: A Rich Population of Asteroseismic Red Clump, Eclipsing Binary, and Main Sequence Pulsating Stars

Authors: Eric L. Sandquist, Dennis Stello, Torben Arentoft, Karsten Brogaard, Frank Grundahl, Andrew Vanderburg, Anne Hedlund, Ryan DeWitt, Taylor R. Ackerman, Miguel Aguilar, Andrew J. Buckner, Christian Juarez, Arturo J. Ortiz, David Richarte, Daniel I. Rivera, Levi Schlapfer

Comments: Accepted to AJ. 28 pages, 25 figures, 5 tables

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)

We present a survey of variable stars detected in K2 Campaign 13 within the massive intermediate age ($\sim1$ Gyr) open cluster NGC 1817. We identify a complete sample of 44 red clump stars in the cluster, and have measured asteroseismic quantities ($\nu_{\rm max}$ and/or $\Delta \nu$) for 29 of them. Five stars showed suppressed dipole modes, and the occurrence rates indicate that mode suppression is unaffected by evolution through core helium burning. A subset of the giants in NGC 1817 (and in the similarly aged cluster NGC 6811) have $\nu_{\rm max}$ and $\Delta \nu$ values at or near the maximum observed for core helium burning stars, indicating they have core masses near the minimum for fully non-degenerate helium ignition. Further asteroseismic study of these stars can constrain the minimum helium core mass in red clump stars and the physics that determines this limit.
Two giant stars show photometric variations on timescales similar to previously measured spectroscopic orbits. Thirteen systems in the field show eclipses, but only five are probable cluster members.
We identify 32 $\delta$ Sct pulsators, 27 $\gamma$ Dor candidates, and 7 hybrids that are probable cluster members, with most new detections. We used the ensemble properties of the $\delta$ Sct stars to identify stars with possible radial pulsation modes. Among the oddities we have uncovered are: an eccentric orbit for a short-period binary containing a $\delta$ Sct pulsating star; a rare subgiant within the Hertzsprung gap showing $\delta$ Sct pulsations; and two hot $\gamma$ Dor pulsating star candidates.

[22]  arXiv:2001.01850 [pdf, ps, other]

Title: Li abundances for solar twins in the open cluster M67

Authors: Marilia Carlos, Jorge Melendez, Jose-Dias do Nascimento Jr., Matthieu Castro

Comments: 6 pages, 3 figures. Accepted for publication at MNRAS

Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

We determine lithium (Li) abundances for solar twins in the M67 open cluster to add valuable information about the correlation between Li depletion and stellar age and, then, better understand stellar structure and evolution. We use high resolution and good signal-to-noise ratio spectra to characterize Li depletion in three solar twins from M67, using spectral synthesis in the region of the asymmetric 6707.75 \AA \, Li I feature. The mean Li abundance value of A(Li)$=1.6\pm0.2$ dex for our sample of M67 solar twins (our three stars plus a fourth solar twin from a previous analysis in the literature) presents Li abundance expected for its age. Also, the scatter estimated from the standard deviation of the Li abundances in this work is similar to the typical scatter found in a sample of field solar twins presented in the literature.

[23]  arXiv:2001.01853 [pdf, ps, other]

Title: Starbursting [O III] emitters and quiescent [C II] emitters in the reionization era

Authors: Shohei Arata, Hidenobu Yajima, Kentaro Nagamine, Makito Abe, Sadegh Khochfar

Comments: 16 pages, 18 figures, 1 table

Subjects: Astrophysics of Galaxies (astro-ph.GA)

Recent observations have successfully detected [O III] $88.3\,{\rm \mu m}$ and [C II] $157.6\,{\rm \mu m}$ lines from galaxies in the early Universe with the Atacama Large Millimeter Array (ALMA). Combining cosmological hydrodynamic simulations and radiative transfer calculations, we present relations between the metal line emission and galaxy evolution at $z=6-15$. We find that galaxies during their starburst phases have high [O III] luminosity of $\sim 10^{42}~\rm erg~s^{-1}$. Once supernova feedback quenches star formation, [O III] luminosities rapidly decrease and continue to be zero for $\sim 100\,{\rm Myr}$. The slope of the relation between $\log{(\rm SFR/M_{\odot}~yr^{-1})}$ and $\log{(L_{\rm [O_{III}]}/{\rm L_{\odot}})}$ at $z=6-9$ is 1.03, and 1.43 for $\log{(L_{\rm [C_{II}]}/{\rm L_{\odot}})}$. As gas metallicity increases from sub-solar to solar metallicity by metal enrichment from star formation and feedback, the line luminosity ratio $L_{\rm [O_{III}]} / L_{\rm [C_{II}]}$ decreases from $\sim 10$ to $\sim 1$ because the O/C abundance ratio decreases due to carbon-rich winds from AGB stars. Therefore, we suggest that the combination of [O III] and [C II] lines is a good probe to investigate the relative distribution of ionized and neutral gas in high-$z$ galaxies. In addition, we show that deep [C II] observations with a sensitivity of $\sim 10^{-2}~{\rm mJy~arcsec^{-2}}$ can probe the extended neutral gas disks of high-$z$ galaxies.

[24]  arXiv:2001.01857 [pdf, other]

Title: A novel experimental setup for an oblique impact onto an inclined granular layer

Authors: Shinta Takizawa, Ryusei Yamaguchi, Hiroaki Katsuragi

Comments: 9 pages, 8 figures

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Soft Condensed Matter (cond-mat.soft); Instrumentation and Detectors (physics.ins-det)

We develop an original apparatus of the granular impact experiment by which the incident angle of the solid projectile and inclination angle of the target granular layer can be systematically varied. Whereas most of the natural cratering events occur on inclined surfaces with various incident angles, there have not been any experiments on oblique impacts on an inclined target surface. To perform systematic impact experiments, a novel experimental apparatus has to be developed. Therefore, we build an apparatus for impact experiments where both the incident angle and the inclination angle can be independently varied. The projectile-injection unit accelerates a plastic ball (6~mm in diameter) up to $v_i\simeq 100$~m~s$^{-1}$ impact velocity. The barrel of the injection unit is made with a three-dimensional printer. The impact dynamics is captured by high-speed cameras to directly measure the impact velocity and incident angle. The rebound dynamics of the projectile (restitution coefficient and rebound angle) is also measured. The final crater shapes are measured using a line-laser profiler mounted on the electric stages. By scanning the surface using this system, a three-dimensional crater shape (height map) can be constructed. From the measured result, we can define and measure the characteristic quantities of the crater. The analyzed result on the restitution dynamics is presented as an example of systematic experiments using the developed system.

[25]  arXiv:2001.01864 [pdf, other]

Title: Full-sky searches for anisotropies in UHECR arrival directions with the Pierre Auger Observatory and the Telescope Array

Authors: A. di Matteo, T. Bister, J. Biteau, L. Caccianiga, O. Deligny, T. Fujii, D. Harari, D. Ivanov, K. Kawata, J.P. Lundquist, R. Menezes, D. Mockler, T. Nonaka, H. Sagawa, P. Tinyakov, I. Tkachev, S. Troitsky (for the Pierre Auger Collaboration and the Telescope Array Collaboration)

Comments: 8 pages, 6 figures; presented at the 36th International Cosmic Ray Conference (ICRC 2019), 24 July--1 August 2019, Madison, Wisconsin, USA

Journal-ref: PoS(ICRC2019)439

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

The arrival directions of ultra-high-energy cosmic rays appear to be approximately isotropically distributed over the whole sky, but the last-generation UHECR detector arrays, the Pierre Auger Observatory (Auger) and the Telescope Array (TA), have detected thousands of events, allowing us to study small deviations from isotropy. So far, Auger has detected a large-scale anisotropy consistent with a $\sim 6.5\%$ dipole moment in the distribution of cosmic rays with $E > 8$~EeV, and both collaborations have reported indications for smaller-scale anisotropies at higher energies. On the other hand, neither array has full-sky coverage, the Auger field of view being limited to declinations $\delta < +45^\circ$ and the TA one to $\delta > -16^\circ$. Searches for anisotropies with full-sky coverage thus require combining data from both arrays. A working group with members from both collaborations has been established for this task. Since even a minor systematic error in the energy determinations at either of the arrays could result in a sizeable spurious anisotropy along the north--south axis, we devised a method to cross-calibrate the energy scales of the two experiments with respect to each other by using events in a declination band within the intersection of their fields of view. In this contribution, we report on both updates on blind searches for anisotropies and the first full-sky studies of flux models based on possible local extragalactic sources.

[26]  arXiv:2001.01892 [pdf, other]

Title: The roles of individual advanced LIGO detectors on revealing the neutron star properties

Authors: Ming-zhe Han, Jin-liang Jiang, Shao-peng Tang, Yin-jie Li, Yi-zhong Fan

Comments: 9 pages, 5 figures

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc)

In this work we re-analyze the data of GW170817, the first binary neutron star (BNS) merger event, in two ways, including the parameterized equation of state (EoS) method and gravitational wave (GW) parameter estimation analysis. Three sets of data, including the combined LIGO/Virgo (HLV) data, the LIGO-Hanford (H1) data and the LIGO-Livingston (L1) data, have been analyzed, respectively. We confirm the bimodal probability distribution of the tidal deformability of GW170817 with the HLV data and resolve the different contributions of H1 and L1 detectors. Our simulation reveals a tendency of ``overestimating" the tidal parameter with the decreasing signal-to-noise ratio (SNR). Such a tendency is likely caused by the dependence of the result on the prior (which is not well understood and has been assumed to be widely-distributed) in the low SNR case. Though this effect is interesting, the slightly higher SNR of H1 than L1 at frequencies above $\sim 100$ Hz is most-likely not the main reason for the lower tidal parameter region favored by H1. In view of the large fluctuation of the expected tide parameter in the case of low SNR, the different probability distributions favored by the L1 and H1 data of GW170817 are reasonable. We have also explored the dependence of expected difference of SNRs of H1 and L1 detectors on the source locations in the O3 and full sensitivity runs. Such maps are helpful in evaluating the relative powers of individual detectors on measuring the tidal deformabilities for the new double neutron star merger events.

[27]  arXiv:2001.01927 [pdf, other]

Title: Numerical viscosity in simulations of the two-dimensional Kelvin-Helmholtz instability

Authors: Martin Obergaulinger (TU Darmstadt), Miguel-Ángel Aloy (Universitat de València)

Comments: 9 pages, 4 figures. Proceedings for the "ASTRONUM 2019" conference, July 2019, Paris, France

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Computational Physics (physics.comp-ph)

The Kelvin-Helmholtz instability serves as a simple, well-defined setup for assessing the accuracy of different numerical methods for solving the equations of hydrodynamics. We use it to extend our previous analysis of the convergence and the numerical dissipation in models of the propagation of waves and in the tearing-mode instability in magnetohydrodynamic models. To this end, we perform two-dimensional simulations with and without explicit physical viscosity at different resolutions. A comparison of the growth of the modes excited by our initial perturbations allows us to estimate the effective numerical viscosity of two spatial reconstruction schemes (fifth-order monotonicity preserving and second-order piecewise linear schemes).

[28]  arXiv:2001.01931 [pdf, other]

Title: Low Pressure EUV Photochemical Experiments: Insight on the Ion-Chemistry Occurring in Titan's Atmosphere

Authors: Jérémy Bourgalais, Nathalie Carraso, Ludovic Vettier, Pascal Pernot

Journal-ref: Journal of Geophysical Research: Space Physics, Volume124, Issue11, November 2019, Pages 9214-9228

Subjects: Earth and Planetary Astrophysics (astro-ph.EP)

Thanks to the \textit{Cassini} spacecraft onboard instruments, it has been known that Titan's ionospheric chemistry is complex and the molecular growth is initiated through the photolysis of the most abundant species directly in the upper atmosphere. Among the pool of chemical compounds formed by the photolysis, N-bearing species are involved in the haze formation but the chemical incorporation pathways need to be better constrained.}\\ In this work, we performed low-pressure EUV photochemical laboratory experiments. The APSIS reactor was filled with a N$_2$/CH$_4$ (90/10\%) gas mixture relevant to the upper atmosphere of Titan. The cell was irradiated by using a EUV photon source at 73.6 nm {which has been difficult to produce in the laboratory for previous studies.}. The photoproducts (both neutral and ionic species) were monitored \textit{in situ} with a quadrupole mass spectrometer. The chemical pathways are explained by confronting experimental observations and numerical predictions of the photoproducts. \\ The most interesting result in this work is that methanimine was the only stable N-bearing neutral molecule detected during the experiments and it relies on N$_2^+$ production. This experimental result is in agreement with the relatively high abundance predicted by 1D-photochemical models of Titan's atmosphere and comforts methanimine as an intermediate towards the formation of complex N-bearing organic molecules.\\ {This experiment is only testing one part of the overall chemical scheme for Titan's upper atmosphere due to the selective wavelength but demonstrates the capability to probe the chemical pathways occurring in Titan's atmosphere by minimizing bias coming from wall surface reactions.}

[29]  arXiv:2001.01932 [pdf, ps, other]

Title: The mean tilt of sunspot bipolar regions: theory, simulations and comparison with observations

Authors: N. Kleeorin, N. Safiullin, K. Kuzanyan, I. Rogachevskii, A. Tlatov, S. Porshnev

Comments: 9 pages, 5 figures, mn2e.cls

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Plasma Physics (physics.plasm-ph)

A theory of the mean tilt of sunspot bipolar regions (the angle between a line connecting the leading and following sunspots and the solar equator) is developed. A mechanism of formation of the mean tilt is related to the effect of Coriolis force on meso-scale motions of super-granular convection and large-scale meridional circulation. The balance between the Coriolis force and the Lorentz force (the magnetic tension) determines a contribution of the large-scale magnetic field to the mean tilt of the sunspot bipolar regions at low latitudes. In addition, the latitudinal dependence of the solar differential rotation affects the mean tilt which can explain deviations from the Joy's law for the sunspot bipolar regions at high latitudes. The obtained theoretical results and performed numerical simulations based on the nonlinear mean-field dynamo theory which takes into account conservation of the total magnetic helicity are in agreement with observational data of the mean tilt of sunspot bipolar regions over individual solar cycles 15 - 24.

[30]  arXiv:2001.01934 [pdf, other]

Title: Effect of metallicity on the detectability of rotational periods in solar-like stars

Authors: V. Witzke, T. Reinhold, A. I. Shapiro, N. A. Krivova, S. K. Solanki

Comments: 9 pages, 7 figures, accepted in A&A

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP)

Accurate determination of stellar rotation periods is important for estimating stellar ages as well as for understanding stellar activity and evolution. While for about thirty thousand stars in the Kepler field rotation periods can be determined, there are over hundred thousand stars, especially with low photometric variability and irregular pattern of variations, for which rotational periods are unknown. Here, we investigate the effect of metallicity on the detectability of rotation periods. This is done by synthesising light curves of hypothetical stars, which are identical to our Sun, with the exception of the metallicity. These light curves are then used as an input to the period determination algorithms. We find that the success rate for recovering the rotation signal has a minimum close to the solar metallicity value. This can be explained by the compensation effect of facular and spot contributions. In addition, selecting solar-like stars with near-solar effective temperature, near solar photometric variability, and with metallicity between M/H = -0.35 and M/H = 0.35 from the Kepler sample, we analyse the fraction of stars for which rotational periods have been detected as a function of metallicity. In agreement with our theoretical estimate we found a local minimum for the detection fraction close to the solar metallicity. We further report rotation periods of 87~solar-like Kepler stars for the first time.

[31]  arXiv:2001.01956 [pdf, ps, other]

Title: NuSTAR perspective on high-redshift MeV blazars

Authors: L. Marcotulli, V. Paliya, M. Ajello, A. Kaur, S. Marchesi, M. Rajagopal, D. Hartmann, D. Gasparrini, R. Ojha, G. Madejski

Comments: 17 pages, 7 figures, 8 tables, 1 appendix, accepted for publication in ApJ

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

With bolometric luminosities exceeding $10^{48}$ erg s$^{-1}$, powerful jets and supermassive black holes at their center, MeV blazars are some of the most extreme sources in the Universe. Recently, the Fermi-Large Area Telescope detected five new $\gamma$-ray emitting MeV blazars beyond redshift $z=3.1$. With the goal of precisely characterizing the jet properties of these extreme sources, we started a multiwavelength campaign to follow them up with joint NuSTAR, Swift and SARA observations. We observe six high-redshift quasars, four of them belonging to the new $\gamma$-ray emitting MeV blazars. Thorough X-ray analysis reveals spectral flattening at soft X-ray for three of these objects. The source NVSS J151002$+$570243 also shows a peculiar re-hardening of the X-ray spectrum at energies $E>6\,\rm keV$. Adopting a one-zone leptonic emission model, this combination of hard X-rays and $\gamma$-rays enables us to determine the location of the Inverse Compton peak and to accurately constrain the jet characteristics. In the context of the jet-accretion disk connection, we find that all six sources have jet powers exceeding accretion disk luminosity, seemingly validating this positive correlation even beyond $z>3$. Our six sources are found to have $10^9 \rm M_{\odot}$ black holes, further raising the space density of supermassive black holes in the redshift bin $z=[3,4]$.

[32]  arXiv:2001.01967 [pdf, ps, other]

Title: Neglected X-ray discovered polars: II: The peculiar eclipsing binary HY Eridani

Authors: K. Beuermann (1), V. Burwitz (2), K. Reinsch (1), A. Schwope (3), H.-C. Thomas (4) ((1) Institut für Astrophysik, Georg-August-Universität Göttingen (2) MPI für extraterrestrische Physik, Garching, (3) Leibniz-Institut für Astrophysik Potsdam (AIP), (4) MPI für Astrophysik, Garching, Deceased 18 January 2012)

Comments: 17 pages, 11 figures, accepted for publication in A\&A

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); High Energy Astrophysical Phenomena (astro-ph.HE)

We report on the X-ray observations of the eclipsing polar HY Eri (RX J0501-0359), along with its photometric, spectrophotometric, and spectropolarimetric optical variations, collected over 30 years. With an orbital period of 2.855 h, HY Eri falls near the upper edge of the 2-3 h period gap. After 2011, the system went into a prolonged low state, continuing to accrete at a low level. We present an accurate alias-free long-term orbital ephemeris and report a highly significant period change by 10 ms that took place over the time interval from 2011 to 2018. We acquired a high-quality eclipse spectrum that shows the secondary star as a dM5-6 dwarf at a distance $d = 1050 \pm 110$ pc. Based on phase-resolved cyclotron and Zeeman spectroscopy, we identify the white dwarf (WD) in HY Eri as a two-pole accretor with nearly opposite accretion spots of 28 and 30 MG. The Zeeman analysis of the low state spectrum reveals a complex magnetic field structure, which we fit by a multipole model. We detected narrow emission lines from the irradiated face of the secondary star, of which Mg I $\lambda 5170$ with a radial velocity amplitude of $K_2' = 139 \pm 10$ km/s (90% confidence) tracks the secondary more reliably than the narrow H$\alpha$ line. Based on the combined dynamical analysis and spectroscopic measurement of the angular radius of the WD, we obtain a primary mass of $M_1 = 0.42 \pm 0.05$ $M_\odot$ (90% confidence errors), identifying it as a probable He WD or hybrid HeCO WD. The secondary is a main sequence star of $M_2 = 0.24 \pm 0.04$ $M_\odot$ that seems to be slightly inflated. The large distance of HY Eri and the lack of similar systems suggest a very low space density of polars with low-mass primary. According to current theory, these systems are destroyed by induced runaway mass transfer, suggesting that HY Eri may be doomed to destruction.

[33]  arXiv:2001.01968 [pdf, ps, other]

Title: Self-consistent modelling of aromatic dust species and extinction curves in galaxy evolution

Authors: Hiroyuki Hirashita, Maria S. Murga

Comments: 15 pages, 9 figures, accepted for publication in MNRAS

Subjects: Astrophysics of Galaxies (astro-ph.GA)

We formulate and calculate the evolution of dust in a galaxy focusing on the distinction among various dust components -- silicate, aromatic carbon, and non-aromatic carbon. We treat the galaxy as a one-zone object and adopt the evolution model of grain size distribution developed in our previous work. We further include aromatization and aliphatization (inverse reaction of aromatization). We regard small aromatic grains in a radius range of 3--50 \AA\ as polycyclic aromatic hydrocarbons (PAHs). We also calculate extinction curves in a consistent manner with the abundances of silicate and aromatic and non-aromatic carbonaceous dust. Our model nicely explains the PAH abundance as a function of metallicity in nearby galaxies. The extinction curve become similar to the Milky Way curve at age $\sim$ 10 Gyr, in terms of the carbon bump strength and the far-ultraviolet slope. We also apply our model to starburst galaxies by shortening the star formation time-scale (0.5 Gyr) and increasing the dense-gas fraction (0.9), finding that the extinction curve maintains bumpless shapes (because of low aromatic fractions), which are similar to the extinction curves observed in the Small Magellanic Cloud and high-redshift quasars. Thus, our model successfully explains the variety in extinction curve shapes at low and high redshifts.

[34]  arXiv:2001.01970 [pdf, other]

Title: xGASS: HI fueling of star formation in disk-dominated galaxies

Authors: Jing Wang, Barbara Catinella, Amelie Saintonge, Zhizheng Pan, Paolo Serra, Li Shao

Comments: 13 pages, 12 figures, accepted for publication at ApJ

Subjects: Astrophysics of Galaxies (astro-ph.GA)

We introduce a method to estimate the HI mass within the optical radius of disk galaxies from integrated HI spectra, with an uncertainty of 0.09 dex. We use these estimates to study how inner HI fuels star formation in late-type disk galaxies. We find that star formation rate (SFR) at a given stellar mass ($M_*$) is well correlated with the inner HI surface density ($\Sigma_{\rm HI,in}$) and inner HI mass-to-stellar mass ratio. For the massive ($M_*>10^{10} M_{\odot}$) disk galaxies, higher SFR at a given stellar mass is also related with higher efficiency of converting inner HI to molecular gas, but no such correlation is found for the total HI mass. The highest $\Sigma_{\rm HI,in}$ and the fastest depletion of the total neutral gas within the optical disks are found in the most compact and star-forming disk galaxies at a given stellar mass. These results highlight the important role of inner HI as an intermediate step of fueling star formation in disk galaxies.

[35]  arXiv:2001.01975 [pdf, ps, other]

Title: First Detection of X-Ray Line Emission from Type IIn Supernova 1978K with XMM-Newton's RGS

Authors: Y. Chiba, S. Katsuda, T. Yoshida, K. Takahashi, H. Umeda

Comments: 10 pages, 6 figures, accepted for publication in PASJ

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

We report on robust measurements of elemental abundances of the Type IIn supernova SN 1978K, based on the high-resolution X-ray spectrum obtained with the Reflection Grating Spectrometer (RGS) onboard XMM-Newton. The RGS clearly resolves a number of emission lines, including N Ly$\alpha$, O Ly$\alpha$, O Ly$\beta$, Fe XVII, Fe XVIII, Ne He$\alpha$ and Ne Ly$\alpha$ for the first time from SN 1978K. The X-ray spectrum can be represented by an absorbed, two-temperature thermal emission model, with temperatures of $kT \sim 0.6$ keV and $2.7$ keV. The elemental abundances are obtained to be N $=$ $2.36_{-0.80}^{+0.88}$, O $=$ $0.20 \pm{0.05}$, Ne $=$ $0.47 \pm{0.12}$, Fe $=$ $0.15_{-0.02}^{+0.01}$ times the solar values. The low metal abundances except for N show that the X-ray emitting plasma originates from the circumstellar medium blown by the progenitor star. The abundances of N and O are far from CNO-equilibrium abundances expected for the surface composition of a luminous blue variable, and resemble the H-rich envelope of less-massive stars with masses of 10-25 M$_\odot$. Together with other peculiar properties of SN 1978K, i.e., a low expansion velocity of 500-1000 km s$^{-1}$ and SN IIn-like optical spectra, we propose that SN 1978K is a result of either an electron-capture SN from a super asymptotic giant branch star, or a weak Fe core-collapse explosion of a relatively low-mass ($\sim$10 M$_\odot$) or high-mass ($\sim$20-25 M$_\odot$) red supergiant star. However, these scenarios can not naturally explain the high mass-loss rate of the order of $\dot{M} \sim 10^{-3} \rm{M_{\odot}\ yr^{-1}}$ over $\gtrsim$1000 yr before the explosion, which is inferred by this work as well as many other earlier studies. Further theoretical studies are required to explain the high mass-loss rates at the final evolutionary stages of massive stars.

[36]  arXiv:2001.01993 [pdf, other]

Title: Relating streamer flows to density and magnetic structures at the Parker Solar Probe

Authors: Alexis P. Rouillard, Athanasios Kouloumvakos, Angelos Vourlidas, Justin Kasper, Stuart Bale, Nour-Edine Raouafi, Benoit Lavraud, Russell A. Howard, Guillermo Stenborg, Michael Stevens, Nicolas Poirier, Jackie A. Davies, Phillip Hess, Aleida K. Higginson, Michael Lavarra, Nicholeen M. Viall, Kelly Korreck, Rui F. Pinto, Léa Griton, Victor Réville, Philippe Louarn, Yihong Wu, Kévin Dalmasse, Vincent Génot, Anthony W. Case, Phyllis Whittlesey, Davin Larson, Jasper S. Halekas, Roberto Livi, Keith Goetz, Peter R. Harvey, Robert J. MacDowall, David Malaspina, Marc Pulupa, John Bonnell, Thierry Dudok de Witt, Emmanuel Penou

Comments: 15 pages, 8 figures, to appear in the Parker Solar Probe ApJ Special Issue

Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

The physical mechanisms that produce the slow solar wind are still highly debated. Parker Solar Probe's (PSP's) second solar encounter provided a new opportunity to relate in situ measurements of the nascent slow solar wind with white-light images of streamer flows. We exploit data taken by the Solar and Heliospheric Observatory (SOHO), the Solar TErrestrial RElations Observatory (STEREO) and the Wide Imager on Solar Probe to reveal for the first time a close link between imaged streamer flows and the high-density plasma measured by the Solar Wind Electrons Alphas and Protons (SWEAP) experiment. We identify different types of slow winds measured by PSP that we relate to the spacecraft's magnetic connectivity (or not) to streamer flows. SWEAP measured high-density and highly variable plasma when PSP was well connected to streamers but more tenuous wind with much weaker density variations when it exited streamer flows. STEREO imaging of the release and propagation of small transients from the Sun to PSP reveals that the spacecraft was continually impacted by the southern edge of streamer transients. The impact of specific density structures is marked by a higher occurrence of magnetic field reversals measured by the FIELDS magnetometers. Magnetic reversals originating from the streamers are associated with larger density variations compared with reversals originating outside streamers. We tentatively interpret these findings in terms of magnetic reconnection between open magnetic fields and coronal loops with different properties, providing support for the formation of a subset of the slow wind by magnetic reconnection.

[37]  arXiv:2001.01995 [pdf, other]

Title: Derivation of parameters for 3748 FGK stars using H-band spectra from APOGEE Data Release 14

Authors: Pedro Sarmento, Elisa Delgado Mena, Bárbara Rojas-Ayala, Sergi Blanco-Cuaresma

Comments: 16 pages, 19 figures (21 pages, 22 figures if appendix included). Accepted by Astronomy and Astrophysics on 23/12/2019

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)

The Apache Point Observatory Galactic Evolution Experiment (APOGEE) has observed the H-band spectra of over 200 000 stars with $R\sim22 000$. The main motivation for this work is to test an alternative method to the standard APOGEE pipeline (APOGEE Stellar Parameter and Chemical Abundances Pipeline, ASPCAP) to derive parameters in the Near-InfraRed (NIR) for FGK dwarfs. \textit{iSpec} and \textit{Turbospectrum} are used to generate synthetic spectra matching APOGEE observations and to determine the parameters through $\chi^2$ minimization. We present spectroscopic parameters ($T_\mathrm{eff}$, $[M/H]$, $\log g$, $v_{mic}$) for a sample of 3748 main-sequence and subgiant FGK stars, obtained from their APOGEE H-band spectra We compare our output parameters with the ones obtained with ASPCAP for the same stellar spectra, and find that the values agree within the expected uncertainties. A comparison with the optical samples California Planet Survey, HARPS-GTO (High Accuracy Radial Velocity Planet Searcher - Guaranteed Time Observations), and PASTEL, is also available, and median differences below 10 K for $T_\mathrm{eff}$ and 0.2 dex for $[M/H]$ are found. Reasons for these differences are explored. The full H-band line-list, the line selection for the synthesis and the synthesized spectra are available for download, as well as the calculated parameters and their estimated uncertainties.

[38]  arXiv:2001.02007 [pdf, ps, other]

Title: Fast radio bursts from reconnection in magnetar magnetosphere

Authors: Yuri Lyubarsky

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

The nearly 100% linear polarization has been reported for a few fast radio bursts. This finding places severe limits on the emission mechanism. I argue that the totally polarized radiation could be generated in the course of relativistic magnetic reconnection in the outer magnetosphere of the magnetar. At the onset of the magnetar flare, a large scale magnetic perturbation forms a magnetic pulse, which propagates from the flare cite outwards. The pulse strongly compresses magnetospheric plasma and pushes it away. The high-frequency MHD waves are generated when the magnetic pulse reaches the current sheet separating, just beyond the light cylinder, the oppositely directed magnetic fields. Coalescence of magnetic islands in the reconnecting current sheet produces magnetosonic waves, which propagate away on the top of the magnetic pulse and escape in the far zone of the wind as radio waves polarized along the rotational axis of the magnetar. I estimate parameters of the outgoing radiation and show that they are compatible with the observed properties of FRBs.

[39]  arXiv:2001.02009 [pdf, other]

Title: Spatio-temporal energy partitioning in a non-thermally dominated two-loop solar flare

Authors: Galina G. Motorina, Gregory D. Fleishman, Eduard P. Kontar

Comments: 23 pages, 10 figures, 1 table, ApJ, accepted

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); High Energy Astrophysical Phenomena (astro-ph.HE)

Solar flares show remarkable variety of the energy partitioning between thermal and nonthermal components. Those with a prominent nonthermal component but only a modest thermal one are particularly well suited to study the direct effect of the nonthermal electrons on plasma heating. Here, we analyze such a well observed, impulsive single-spike nonthermal event, a SOL2013-11-05T035054 solar flare, where the plasma heating can be entirely attributed to the energy losses of these impulsively accelerated electrons. Evolution of the energy budget of thermal and nonthermal components during the flare is analysed using X-ray, microwave, and EUV observations and three-dimensional modeling. The results suggest that (i) the flare geometry is consistent with a two-loop morphology and the magnetic energy is likely released due to interaction between these two loops; (ii) the released magnetic energy converted to the nonthermal energy of accelerated electrons only, which is subsequently converted to the thermal energy of the plasma; (iii) the energy is partitioned in these two flaring loops in comparable amounts; (iv) one of these flaring loops remained relatively tenuous but rather hot, while the other remained relatively cool but denser than the first one. Therefore, this solar flare demonstrates an extreme efficiency of conversion of the free magnetic energy to the nonthermal energy of particle acceleration and the energy flow into two loops from the non-thermal to thermal one with a negligible direct heating.

[40]  arXiv:2001.02026 [pdf, other]

Title: Radiation spectra of warm and optically thick coronae in AGN

Authors: P.-O. Petrucci (1), D. Gronkiewicz (2), A. Rozanska (2), R. Belmont (3), S. Bianchi (4), B. Czerny (5), G. Matt (4), J. Malzac (6), R. Middei (4), A. De Rosa (7), F. Ursini (8), M. Cappi (8) ((1) Univ. Grenoble Alpes, CNRS, IPAG, France, (2) Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences, Warsaw, Poland, (3) Laboratoire AIM (CEA/IRFU - CNRS/INSU - Universite Paris Diderot), CEA DSM/IRFU/SAp, Gif-sur-Yvette, France, (4) Dipartimento di Matematica e Fisica, Universita` degli Studi Roma Tre, Roma, Italy, (5) Center for Theoretical Physics, Polish Academy of Sciences, Warsaw, Poland, (6) IRAP, Universite de Toulouse, CNRS, UPS, CNES, Toulouse, France, (7) INAF-Istituto di Astrofisica e Planetologie Spaziali, Rome, Italy, (8) INAF-Osservatorio di astrofisica e scienza dello spazio di Bologna, Bologna, Italy)

Comments: Accepted for publication in A&A. 13 pages, 8 Figures

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

A soft X-ray excess above the 2-10 keV power law extrapolation is generally observed in AGN X-ray spectra. Presently there are two competitive models to explain it: blurred ionized reflection and warm Comptonisation. In the latter case, observations suggest a corona temperature $\sim$ 1 keV and a corona optical depth $\sim$ 10. Moreover, radiative constraints from spectral fits with Comptonisation models suggest that most of the accretion power should be released in the warm corona. The disk below is basically non-dissipative, radiating only the reprocessed emission from the corona. The true radiative properties of such a warm and optically thick plasma are not well-known, however. For instance, the importance of the Comptonisation process, the potential presence of strong absorption/emission features or the spectral shape of the output spectrum have been studied only very recently. We present in this paper simulations of warm and optically thick coronae using the TITAN radiative transfer code coupled with the NOAR Monte-Carlo code, the latter fully accounting for Compton scattering of continuum and lines. Illumination from above by a hard X-ray emission and from below by an optically thick accretion disk is taken into account as well as (uniform) internal heating. Our simulations show that for a large part of the parameter space, the warm corona with sufficient internal mechanical heating is dominated by Compton cooling and neither strong absorption nor emission lines are present in the outgoing spectra. In a smaller part of the parameter space, the calculated emission agrees with the spectral shape of the observed soft X-ray excess. Remarkably, this also corresponds to the conditions of radiative equilibrium of an extended warm corona covering almost entirely a non-dissipative accretion disk. These results confirm the warm Comptonisation as a valuable model for the soft X-ray excess.

[41]  arXiv:2001.02100 [pdf, ps, other]

Title: The effects of plasma lensing on the inferred dispersion measures of Fast Radio Bursts

Authors: Xinzhong Er, Yuanpei Yang, Adam Rogers

Comments: comments welcome

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

Radio signals are delayed when propagating through plasma. This type of delay is frequency-dependent and is usually used for estimating the projected number density of electrons along the line of sight, called the dispersion measure. The dense and clumpy distribution of plasma can cause refractive deflections of radio signals, analogous to lensing effects. Similar to gravitational lensing, there are two contributions to the time delay effect in plasma lensing: a geometric delay, due to increased path length of the signal, and a dispersive delay due to the change of speed of light in a plasma medium. We show the delay time for two models of the plasma distribution, and point out that the estimated dispersion measure can be biased. Since the contribution of the geometric effect can be comparable to that of the dispersive delay, the bias in the measured dispersion measure can be dramatically large if plasma lensing effects are not taken into account when signals propagate through a high-density gradient clump of plasma.

[42]  arXiv:2001.02111 [pdf, other]

Title: Direct Parameter Inference from Global EoR Signal with Bayesian Statistics

Authors: Junhua Gu, Jingying Wang

Comments: 18 pages, 20 figures; to be published in MNRAS

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)

In the observation of sky-averaged HI signal from Epoch of Reionization, model parameter inference can be a computation-intensive work, which makes it hard to perform a direct one-stage model parameter inference by using MCMC sampling method in Bayesian framework. Instead, a two-stage inference is usually used, i.e., the parameters of some characteristic points on the EoR spectrum model are first estimated, which are then used as the input to estimate physical model parameters further. However, some previous works had noticed that this kind of method could bias results, and it could be meaningful to answer the question of whether it is feasible to perform direct one-stage MCMC sampling and obtain unbiased physical model parameter estimations. In this work, we studied this problem and confirmed the feasibility. We find that unbiased estimations to physical model parameters can be obtained with a one-stage direct MCMC sampling method. We also study the influence of some factors that should be considered in practical observations to model parameter inference. We find that a very tiny amplifier gain calibration error ($10^{-5}$ relative error) with complex spectral structures can significantly bias the parameter estimation; the frequency-dependent antenna beam and geographical position can also influence the results, so that should be carefully handled.

[43]  arXiv:2001.02162 [pdf, other]

Title: Meteospace, a New Instrument for Solar Survey at the Calern Observatory

Authors: J.-M. Malherbe, Th Corbard, K. Dalmasse, The Meteospace team

Comments: 16 pages, 10 figures; Accepted for publication in Solar Physics

Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

High cadence observations of solar activity (active regions, flares, filaments) in the H$\alpha$ line were performed at Meudon and Haute Provence Observatories from 1956 to 2004. More than 7 million images were recorded, mainly on 35 mm films. After a review of the scientific interest of solar surveys at high temporal resolution and the historical background, we describe the new instrument which will operate automatically in 2020 at the Calern station of the C\^{o}te d'Azur observatory (1270 m). It will replace the former heliographs with improved cadence, seeing and time coverage. We summarize the capabilities of the optical design and present new scientific perspectives in terms of flare onset and Moreton wave detection.

[44]  arXiv:2001.02179 [pdf, other]

Title: Challenges to modelling from groundbreaking new data of present/future space and ground facilities

Authors: Gisella Clementini, Marcella Marconi, Alessia Garofalo

Comments: 7 pages, 3 figures, invited contribution at the conference "Stars and their variability observed from space - Celebrating the 5th anniversary of BRITE-Constellation", Vienna, Austria, August 19 - 23, 2019. Eds: C. Neiner, W. Weiss, D. Baade, E. Griffin, C. Lovekin, A. Moffat

Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

The sheer size of high-accuracy, multi-band photometry, spectroscopy, astrometry and seismic data that space missions like Kepler, Gaia, PLATO, TESS, JWST and ground-based facilities under development such as MOONS, WEAVE and the LSST will produce within the next decade, brings big opportunities to improve current modelling; but it also presents unprecedented challenges to overcome the present limitations in stellar evolution and pulsation models. Such an unprecedented harvest of data also requires multi-tasking and synergic approaches to be interpreted and fully exploited. We briefly review major outputs expected from ongoing/planned facilities and large sky surveys, then focus specifically on Gaia and present a few examples of the impact that this mission is having on studies of stellar physics, Galactic structure and the cosmic distance ladder.

[45]  arXiv:2001.02180 [pdf, other]

Title: Forecasting Dark-Energy Anisotropic Stress using gravitational-waves

Authors: Weiqiang Yang, Supriya Pan, David F. Mota, Minghui Du

Comments: 15 pages, 5 tables and 10 figures. Comments are welcome

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc)

We confront the dark energy anisotropic stress using the usual cosmological probes namely cosmic microwave background radiation, baryon acoustic oscillations, latest pantheon sample of supernovae type Ia and then make use of the simulated gravitational waves standard sirens (GWSS) data from Einstein Telescope with an aim to examine the constraining power of the simulated GWSS data over the standard cosmological probes. Our analyses show that GWSS can give better constraints on the model parameters compared to the usual cosmological probes, but the viscous sound speed appearing due to the dark energy anisotropic stress, is totally unconstrained even after the inclusion of GWSS.

[46]  arXiv:2001.02185 [pdf, ps, other]

Title: The Sun at millimeter wavelengths I. Introduction to ALMA Band 3 observations

Authors: Sven Wedemeyer, Mikolaj Szydlarski, Shahin Jafarzadeh, Henrik Eklund, Juan Camilo Guevara Gomez, Tim Bastian, Bernhard Fleck, Jaime de la Cruz Rodriguez, Andrew Rodger, Mats Carlsson

Comments: 14 pages, 9 figures; accepted for publication in A&A

Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

We present an initial study of one of the first ALMA Band 3 observations of the Sun with the aim to characterise the diagnostic potential of brightness temperatures measured with ALMA on the Sun. The observation covers 48min at a cadence of 2s targeting a Quiet Sun region at disk-centre. Corresponding time series of brightness temperature maps are constructed with the first version of the Solar ALMA Pipeline (SoAP) and compared to simultaneous SDO observations. The angular resolution of the observations is set by the synthesized beam (1.4x2.1as). The ALMA maps exhibit network patches, internetwork regions and also elongated thin features that are connected to large-scale magnetic loops as confirmed by a comparison with SDO maps. The ALMA Band 3 maps correlate best with the SDO/AIA 171, 131 and 304 channels in that they exhibit network features and, although very weak in the ALMA maps, imprints of large-scale loops. A group of compact magnetic loops is very clearly visible in ALMA Band 3. The brightness temperatures in the loop tops reach values of about 8000-9000K and in extreme moments up to 10 000K. ALMA Band 3 interferometric observations from early observing cycles already reveal temperature differences in the solar chromosphere. The weak imprint of magnetic loops and the correlation with the 171, 131, and 304 SDO channels suggests though that the radiation mapped in ALMA Band 3 might have contributions from a larger range of atmospheric heights than previously assumed but the exact formation height of Band 3 needs to be investigated in more detail. The absolute brightness temperature scale as set by Total Power measurements remains less certain and must be improved in the future. Despite these complications and the limited angular resolution, ALMA Band 3 observations have large potential for quantitative studies of the small-scale structure and dynamics of the solar chromosphere.

[47]  arXiv:2001.02187 [pdf, other]

Title: Explaining the chemical trajectories of accreted and in-situ halo stars of the Milky Way

Authors: Chris B. Brook, Daisuke Kawata, Brad K. Gibson, Carme Gallart

Comments: Submitted to MNRAS on 21 October 2019. Still awaiting referee report

Subjects: Astrophysics of Galaxies (astro-ph.GA)

The Milky Way underwent its last significant merger ten billion years ago, when the Gaia-Enceladus-Sausage (GES) was accreted. Accreted GES stars and progenitor stars born prior to the merger make up the bulk of the inner halo. Even though these two main populations of halo stars have similar $durations$ of star formation prior to their merger, they differ in [$\alpha$/Fe]-[Fe/H] space, with the GES population bending to lower [$\alpha$/Fe] at a relatively low value of [Fe/H]. We use cosmological simulations of a 'Milky Way' to argue that the different tracks of the halo stars through the [$\alpha$/Fe]-[Fe/H] plane are due to a difference in their star formation history and efficiency, with the lower mass GES having its low and constant star formation regulated by feedback whilst the higher mass main progenitor has a higher star formation rate prior to the merger. The lower star formation efficiency of GES leads to lower gas pollution levels, pushing [$\alpha$/Fe]-[Fe/H] tracks to the left. In addition, the increasing star formation rate maintains a higher relative contribution of Type~II SNe to Type~Ia SNe for the main progenitor population that formed during the same time period, thus maintaining a relatively high [$\alpha$/Fe]. Thus the different positions of the downturns in the [$\alpha$/Fe]-[Fe/H] plane for the GES stars are not reflective of different star formation durations, but instead reflect different star formation efficiencies. We argue that cosmological simulations match a wide range of independent observations, breaking degeneracies that exist in simpler models.

[48]  arXiv:2001.02193 [pdf, other]

Title: Deciphering the Archaeological Record: Cosmological Imprints of Non-Minimal Dark Sectors

Authors: Keith R. Dienes, Fei Huang, Jeff Kost, Shufang Su, Brooks Thomas

Comments: 55 pages, LaTeX, 21 figures, 4 tables

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph)

Many proposals for physics beyond the Standard Model give rise to a dark sector containing many degrees of freedom. In this work, we explore the cosmological implications of the non-trivial dynamics which may arise within such dark sectors, focusing on decay processes which take place entirely among the dark constituents. First, we demonstrate that such decays can leave dramatic imprints on the resulting dark-matter phase-space distribution. In particular, this distribution need not be thermal --- it can even be multi-modal, exhibiting a non-trivial pattern of peaks and troughs as a function of momentum. We then proceed to show how these features can induce small-scale modifications to the matter power spectrum. Finally, we assess the extent to which one can approach the archaeological "inverse" problem of deciphering the properties of an underlying dark sector from the matter power spectrum. Indeed, one of the main results of this paper is a remarkably simple conjectured analytic expression which permits the reconstruction of many of the important features of the dark-matter phase-space distribution directly from the matter power spectrum. Our results therefore provide an interesting toolbox of methods for learning about, and potentially constraining, the features of non-minimal dark sectors and their dynamics in the early universe.

[49]  arXiv:2001.02211 [pdf, other]

Title: Spectrophotometric calibration of low-resolution spectra

Authors: Michael Weiler, Josep Manel Carrasco, Claus Fabricius, Carme Jordi

Comments: First version submitted to A&A [already incl. very minor corrections]

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)

Low resolution spectroscopy is a frequently used technique. In its form of aperture prism spectroscopy it is an important tool for large scale survey observations. The ongoing ESA space mission Gaia is the currently most relevant case. In this work we analyse the fundamental limitations in the calibration of low resolution spectrophotometric observations and introduce a calibration method which avoids simplifying assumptions on the smearing effects of the line spread functions. To do so, we develop a functional analytic mathematical formulation of the problem of spectrophotometric calibration. In this formulation, the calibration process can be described as a linear mapping between two suitably constructed Hilbert spaces, independent of the resolution of the spectrophotometric instrument. The presented calibration method can provide a formally unusual but precise calibration of low resolution spectrophotometry with non-negligible widths of line spread functions. We have used the Gaia spectrophotometric instruments as a demonstrator to show that the calibration method of this work can potentially provide significantly better synthetic photometry than methods neglecting the smearing effects of the line spread functions.

[50]  arXiv:2001.02217 [pdf, ps, other]

Title: An ultra-short period rocky super-Earth orbiting the G2-star HD 80653

Authors: G. Frustagli, E. Poretti, T. Milbourne, L. Malavolta, A. Mortier, Vikash Singh, A. S. Bonomo, L. A. Buchhave, L. Zeng, A. Vanderburg, S. Udry, G. Andreuzzi, A. Collier-Cameron, R. Cosentino, M. Damasso, A. Ghedina, A. Harutyunyan, R. D. Haywood, D. W. Latham, M. López-Morales, V. Lorenzi, A.F. Martinez Fiorenzano, M. Mayor, G. Micela, E. Molinari, F. Pepe, D. Phillips, K. Rice, A. Sozzetti

Comments: 15 pages, 12 figures; accepted by A&A

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)

Ultra-short period (USP) planets are a class of exoplanets with periods shorter than one day. The origin of this sub-population of planets is still unclear, with different formation scenarios highly dependent on the composition of the USP planets. A better understanding of this class of exoplanets will, therefore, require an increase in the sample of such planets that have accurate and precise masses and radii, which also includes estimates of the level of irradiation and information about possible companions. Here we report a detailed characterization of a USP planet around the solar-type star HD 80653 $\equiv$ EP 251279430 using the K2 light curve and 108 precise radial velocities obtained with the HARPS-N spectrograph, installed on the Telescopio Nazionale Galileo. From the K2 C16 data, we found one super-Earth planet ($R_{b}=1.613\pm0.071 R_{\oplus}$) transiting the star on a short-period orbit ($P_{\rm b}=0.719573\pm0.000021$ d). From our radial velocity measurements, we constrained the mass of HD 80653 b to $M_{b}=5.60\pm0.43 M_{\oplus}$. We also detected a clear long-term trend in the radial velocity data. We derived the fundamental stellar parameters and determined a radius of $R_{\star}=1.22\pm0.01 R_{\odot}$ and mass of $M_{\star}=1.18\pm0.04 M_{\odot}$, suggesting that HD 80653, has an age of $2.7\pm1.2$ Gyr. The bulk density ($\rho_{b} = 7.4 \pm 1.1$ g cm$^{-3}$) of the planet is consistent with an Earth-like composition of rock and iron with no thick atmosphere. Our analysis of the K2 photometry also suggests hints of a shallow secondary eclipse with a depth of 8.1$\pm$3.7 ppm. Flux variations along the orbital phase are consistent with zero. The most important contribution might come from the day-side thermal emission from the surface of the planet at $T\sim3480$ K.

[51]  arXiv:2001.02222 [pdf, other]

Title: A repeating fast radio burst source localised to a nearby spiral galaxy

Authors: B. Marcote, K. Nimmo, J. W. T. Hessels, S. P. Tendulkar, C. G. Bassa, Z. Paragi, A. Keimpema, M. Bhardwaj, R. Karuppusamy, V. M. Kaspi, C. J. Law, D. Michilli, K. Aggarwal, B. Andersen, A. M. Archibald, K. Bandura, G. C. Bower, P. J. Boyle, C. Brar, S. Burke-Spolaor, B. J. Butler, T. Cassanelli, P. Chawla, P. Demorest, M. Dobbs, E. Fonseca, U. Giri, D. C. Good, K. Gourdji, A. Josephy, A. Yu. Kirichenko, F. Kirsten, T. L. Landecker, D. Lang, T. J. W. Lazio, D. Z. Li, H.-H. Lin, J. D. Linford, K. Masui, J. Mena-Parra, A. Naidu, C. Ng, C. Patel, U.-L. Pen, Z. Pleunis, M. Rafiei-Ravandi, M. Rahman, A. Renard, P. Scholz, S. R. Siegel, K. M. Smith, I. H. Stairs, K. Vanderlinde, A. V. Zwaniga

Comments: 61 pages, 11 figures, 3 tables. Published in Nature

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Instrumentation and Methods for Astrophysics (astro-ph.IM)

Fast radio bursts (FRBs) are brief, bright, extragalactic radio flashes. Their physical origin remains unknown, but dozens of possible models have been postulated. Some FRB sources exhibit repeat bursts. Though over a hundred FRB sources have been discovered to date, only four have been localised and associated with a host galaxy, with just one of the four known to repeat. The properties of the host galaxies, and the local environments of FRBs, provide important clues about their physical origins. However, the first known repeating FRB has been localised to a low-metallicity, irregular dwarf galaxy, and the apparently non-repeating sources to higher-metallicity, massive elliptical or star-forming galaxies, suggesting that perhaps the repeating and apparently non-repeating sources could have distinct physical origins. Here we report the precise localisation of a second repeating FRB source, FRB 180916.J0158+65, to a star-forming region in a nearby (redshift $z = 0.0337 \pm 0.0002$) massive spiral galaxy, whose properties and proximity distinguish it from all known hosts. The lack of both a comparably luminous persistent radio counterpart and a high Faraday rotation measure further distinguish the local environment of FRB 180916.J0158+65 from that of the one previously localised repeating FRB source, FRB 121102. This demonstrates that repeating FRBs have a wide range of luminosities, and originate from diverse host galaxies and local environments.

[52]  arXiv:2001.02227 [pdf, other]

Title: ALMA observations of two massive and dense MALT90 clumps

Authors: Sudeep Neupane, Guido Garay, Yanett Contreras, Andres Guzmán, Luis Felipe Rodríguez

Comments: 26 figures, 11 tables, accepted for publication in ApJ (Jan 4, 2020)

Subjects: Astrophysics of Galaxies (astro-ph.GA)

We report Atacama Large Millimeter Array observations of 3 mm dust continuum emission and line emission, in HCO$^{+}$, H$^{13}$CO$^{+}$, N$_{2}$H$^{+}$ and CH$_{3}$CN, towards two massive and dense clumps (MDCs) in early but distinct evolutionary phases (prestellar and protostellar), made with the goal of investigating their fragmentation characteristics at angular scales of $\sim$1 $\arcsec$. Towards the prestellar clump we detected ten compact structures (cores), with radius from 1200 to 4500 AU and masses from 1.6 to 20~M$_\odot$. Half of these cores exhibit inverse P Cygni profiles in HCO$^{+}$ and are subvirialized indicating that they are undergoing collapse. Towards the protostellar clump we detected a massive (119~M$_\odot$) central core, with a strong mass infall rate, and nine less massive cores, with masses from 1.7 to 27~M$_\odot$ and radius from 1000 to 4300 AU. CH$_{3}$CN rotational temperatures were derived for 8 cores in the protostellar clump and 3 cores in the prestellar clump. Cores within the prestellar clump have smaller linewidths and lower temperatures than cores within the protostellar clump. The fraction of total mass in cores to clump mass is smaller in the prestellar clump ($\sim$6\%) than in the protostellar clump ($\sim$23\%). We conclude that we are witnessing the evolution of the dense gas in globally collapsing MDCs; the prestellar clump illustrating the initial stage of fragmentation, harboring cores that are individually collapsing, and the protostellar clump reflecting a later stage in which a considerable fraction of the gas has been gravitationally focused into the central region.

[53]  arXiv:2001.02228 [pdf, other]

Title: Habitability and Water Loss Limits on Eccentric Planets Orbiting Main Sequence Stars

Authors: Igor Palubski, Aomawa Shields, Russell Deitrick

Comments: 22 pages, 9 figures, 2 tables, accepted for publication in the Astrophysical Journal

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)

A planet's climate can be strongly affected by its orbital eccentricity and obliquity. Here we use a 1-dimensional energy balance model modified to include a simple runaway greenhouse (RGH) parameterization to explore the effects of these two parameters on the climate of Earth-like aqua planets - completely ocean-covered planets - orbiting F-, G-, K-, and M-dwarf stars. We find that the range of instellations for which planets exhibit habitable surface conditions throughout an orbit decreases with increasing eccentricity. However, the appearance of temporarily habitable conditions during an orbit creates an eccentric habitable zone (EHZ) that is sensitive to orbital eccentricity and obliquity, planetary latitude, and host star spectral type. We find that the fraction of a planet's orbit over which it exhibits habitable surface conditions is larger on eccentric planets orbiting M-dwarf stars, due to the lower broadband planetary albedos of these planets. Planets with larger obliquities have smaller EHZs, but exhibit warmer climates if they do not enter a snowball state during their orbits. We also find no transient runaway greenhouse state on planets at all eccentricities. Rather, planets spend their entire orbits either in a RGH or not. For G-dwarf planets receiving 100% of the modern solar constant and with eccentricities above 0.55, an entire Earth ocean inventory can be lost in 3.6 Gyr. M-dwarf planets, due to their larger incident XUV flux, can become desiccated in only 690 Myr with eccentricities above 0.38. This work has important implications for eccentric planets that may exhibit surface habitability despite technically departing from the traditional habitable zone as they orbit their host stars.

Cross-lists for Wed, 8 Jan 20

[54]  arXiv:1901.05930 (cross-list from hep-ph) [pdf, other]

Title: Superheavy objects composed of nuclear and dark matter

Authors: Vakhid A. Gani, Maxim Yu. Khlopov, Dmitry N. Voskresensky

Comments: 4 pages; Proceedings of the 4th International Conference on Particle Physics and Astrophysics (ICPPA-2018), Moscow, 22-26 October 2018

Journal-ref: J. Phys.: Conf. Ser. 1390, 012095 (2019)

Subjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); Nuclear Theory (nucl-th)

We consider a model of $O$He atomic dark matter formed by Coulomb binding of the hypothetical stable double-charged massive $O^{--}$ particles with nuclei of primordial helium. Such a dark matter can be captured by ordinary matter forming superheavy nuclei. We propose a possibility of self-bound by nuclear and electromagnetic interaction $O$-nuclearites as well as more massive gravitating ones and discuss effect of accumulation of $O$He atoms in stars and their effect in stellar evolution.

[55]  arXiv:1911.11671 (cross-list from gr-qc) [pdf, other]

Title: Black Hole Ringdown as a Probe for Dark Energy

Authors: Johannes Noller, Luca Santoni, Enrico Trincherini, Leonardo G. Trombetta

Comments: 10+3 pages, 2 figures, 1 table

Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)

Under the assumption that a dynamical scalar field is responsible for the current acceleration of the Universe, we explore the possibility of probing its physics in black hole merger processes with gravitational wave interferometers. Remaining agnostic about the microscopic physics, we use an effective field theory approach to describe the scalar dynamics. We investigate the case in which some of the higher derivative operators, that are highly suppressed on cosmological scales, instead become important on typical distances for black holes. If a coupling to the Gauss-Bonnet operator is one of them, a non-trivial background profile for the scalar field can be sourced in the surrounding of the black hole, resulting in a potentially large amount of `hair'. In turn, this can induce sizeable modifications to the spacetime geometry or a mixing between the scalar and the gravitational perturbations. Both effects will ultimately translate into a modification of the quasi-normal mode spectrum in a way that is also sensitive to other operators besides the one sourcing the scalar background. The presence of deviations from the predictions of general relativity in the observed spectrum can therefore serve as a window onto dark energy physics.

[56]  arXiv:2001.01460 (cross-list from gr-qc) [pdf, ps, other]

Title: Effects of nonlinearity of $f(R)$ gravity and perfect fluid in Kaluza-Klein models with spherical compactification

Authors: Maxim Eingorn, Ezgi Yalçınkaya, Alexander Zhuk

Comments: 14 pages, no figures

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)

We study the effects associated with nonlinearity of $f(R)$ gravity and of the background perfect fluid manifested in the Kaluza-Klein model with spherical compactification. The background space-time is perturbed by a massive gravitating source which is pressureless in the external space but has an arbitrary equation of state (EoS) parameter in the internal space. As characteristics of a nonlinear perfect fluid, the squared speeds of sound are not equal to the background EoS parameters in the external and internal spaces. In this setting, we find exact solutions to the linearized Einstein equations for the perturbed metric coefficients. For nonlinear models with $f^{\prime\prime}(R_0)\neq0$, we show that these coefficients acquire correction terms in the form of two summed Yukawa potentials and that in the degenerated case, the solutions are reduced to a single Yukawa potential with some "corrupted" prefactor (in front of the exponential function), which, in addition to the standard $1/r$ term, contains a contribution independent of the three-dimensional distance $r$. In the linear $f''(R)=0$ model, we generalize the previous studies to the case of an arbitrary nonlinear perfect fluid. We also investigate the particular case of the nonlinear background perfect fluid with zero speed of sound in the external space and demonstrate that a non-trivial solution exists only in the case of $f''(R_0)=0$.

[57]  arXiv:2001.01747 (cross-list from gr-qc) [pdf, other]

Title: Inferring the neutron star equation of state simultaneously with the population of merging neutron stars

Authors: Daniel Wysocki, Richard O'Shaughnessy, Leslie Wade, Jacob Lange

Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE)

Observations of the properties of multiple coalescing neutron stars will simultaneously provide insight into neutron star mass and spin distribution, the neutron star merger rate, and the nuclear equation of state. Not all merging binaries containing neutron stars are expected to be identical. Plausible sources of diversity in these coalescing binaries can arise from a broad or multi-peaked NS mass distribution; the effect of different and extreme NS natal spins; the possibility of NS-BH mergers; or even the possibility of phase transitions, allowing for NS with similar mass but strongly divergent radius. In this work, we provide a concrete algorithm to combine all information obtained from GW measurements into a joint constraint on the NS merger rate, the distribution of NS properties, and the nuclear equation of state. Using a concrete example, we show how biased mass distribution inferences can significantly impact the recovered equation of state, even in the small-$N$ limit. With the same concrete example, we show how small-$N$ observations could identify a bimodal mass and spin distribution for merging NS simultaneously with the EOS. Our concordance approach can be immediately generalized to incorporate other observational constraints.

[58]  arXiv:2001.01760 (cross-list from physics.pop-ph) [pdf]

Title: The Artscience of Planet Formation: import ArtScience.PlanetFormation as AATS

Authors: Sebastián Pérez

Comments: Published in Poi\'esis journal

Journal-ref: Poiesis, Niteroi, v. 20, n. 34, p. 63-70, jul./dez. 2019

Subjects: Popular Physics (physics.pop-ph); Earth and Planetary Astrophysics (astro-ph.EP)

The Art, Astronomy, Technology and Society (AATS) project is an artscience collaboration which dwells in the inbetweenness layer of scientific understanding of the origins of planets and the embodied, intuited ways of knowing. One of the oldest and at the same time one of the newest concerns of humanity is "How did the Earth and the planets come to be?". Planet formation, an intricate and potentially chaotic process, is also very efficient. Every star harbors at least one planet, as evidenced by the high frequency of exoplanet detections. Planet formation must therefore be a frequent process. Yet, learning about the origins of planets has been difficult. Here I share my experience in the AATS artscience project and discuss the nature of artscience collaborations.

[59]  arXiv:2001.01785 (cross-list from hep-th) [pdf, other]

Title: Maximally chaotic dynamical systems of Anosov-Kolmogorov

Authors: George Savvidy

Comments: 64 pages, 15 figures, Invited talk at the International Bogolyubov Conference "Problems of Theoretical and Mathematical Physics" at the Steklov Mathematical Institute, Moscow-Dubna, September 9-13, 2019

Subjects: High Energy Physics - Theory (hep-th); Astrophysics of Galaxies (astro-ph.GA); High Energy Physics - Lattice (hep-lat); Chaotic Dynamics (nlin.CD)

The maximally chaotic K-systems are dynamical systems which have nonzero Kolmogorov entropy. On the other hand, the hyperbolic dynamical systems that fulfil the Anosov C-condition have exponential instability of phase trajectories, mixing of all orders, countable Lebesgue spectrum and positive Kolmogorov entropy. The C-condition defines a rich class of maximally chaotic systems which span an open set in the space of all dynamical systems. The interest in Anosov-Kolmogorov C-K systems is associated with the attempts to understand the relaxation phenomena, the foundation of the statistical mechanics, the appearance of turbulence in fluid dynamics, the non-linear dynamics of the Yang-Mills field as well as the dynamical properties of gravitating N-body systems and the Black hole thermodynamics. In this respect of special interest are C-K systems that are defined on Reimannian manifolds of negative sectional curvature and on a high-dimensional tori. Here we shall review the classical- and quantum-mechanical properties of maximally chaotic dynamical systems, the application of the C-K theory to the investigation of the Yang-Mills dynamics and gravitational systems as well as their application in the Monte Carlo method.

[60]  arXiv:2001.02081 (cross-list from physics.pop-ph) [pdf]

Title: Beyond Boltzmann: The Potential Energy Distribution of Objects in the Atmosphere

Authors: Henry Hess

Comments: 2 pages, 1 figure

Subjects: Popular Physics (physics.pop-ph); Earth and Planetary Astrophysics (astro-ph.EP); Statistical Mechanics (cond-mat.stat-mech)

Estimates of the number and potential energy of molecules, aerosols, cloud droplets, insects, birds, planes and satellites in the atmosphere yield a distribution which is for potential energies below 10^2 kBT described by the Boltzmann distribution, but for the range from 10^2 kBT to 10^33 kBT by a power law with an exponent of approximately -1. An explanation for this surprising behavior is not found.

[61]  arXiv:2001.02085 (cross-list from nucl-ex) [pdf, other]

Title: Nuclear physics uncertainties in neutrino-driven, neutron-rich supernova ejecta

Authors: J. Bliss (Institut fur Kernphysik, Technische Universitat Darmstadt, Germany), A. Arcones (Institut fur Kernphysik, Technische Universitat Darmstadt, Germany and GSI Helmholtzzentrum fur Schwerionenforschung GmbH, Darmstadt, Germany), F. Montes (National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI, USA and Joint Institute for Nuclear Astrophysics), J. Pereira (National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI, USA and Joint Institute for Nuclear Astrophysics)

Subjects: Nuclear Experiment (nucl-ex); High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); Nuclear Theory (nucl-th)

Neutrino-driven ejecta in core collapse supernovae (CCSNe) offer an interesting astrophysical scenario where lighter heavy elements between Sr and Ag can be synthesized. Previous studies emphasized the important role that ($\alpha,n$) reactions play in the production of these elements, particularly in neutron-rich and alpha-rich environments. In this paper, we have investigated the sensitivity of elemental abundances to specific ($\alpha,n$) reaction-rate uncertainties under different astrophysical conditions. Following a Monte Carlo nucleosynthesis study with over 36 representative astrophysical wind conditions, we have identified the most important reactions based on their impact on the final elemental abundances. Experimental studies of these reactions will reduce the nucleosynthesis uncertainties and make it possible to use observations to understand the origin of lighter heavy elements and the astrophysical conditions where they are formed.

[62]  arXiv:2001.02154 (cross-list from hep-th) [pdf, ps, other]

Title: Generalized geometrical coupling for vector field localization on thick brane in asymptotic Anti-de Sitter spacetime

Authors: Tao-Tao Sui, Wen-Di Guo, Qun-Ying Xie, Yu-Xiao Liu

Comments: 8 pages, 4 figures

Subjects: High Energy Physics - Theory (hep-th); High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc)

It is known that a five-dimensional free vector field $A_{M}$ cannot be localized on Randall-Sundrum (RS)-like thick branes, namely, the thick branes embedded in asymptotic Anti-de Sitter (AdS) spacetime. In order to localize a vector field on the RS-like thick brane, an extra coupling term should be introduced. In this paper, we generalize the geometrical coupling mechanism by adding two mass terms ($\alpha Rg^{MN}A_{M}A_{N}+\beta R^{MN}A_{M}A_{N}$) into the action. We decompose the fundamental vector field $A_{M}$ into three parts: transverse vector part $\hat{A}_{\mu}$, scalar parts $\phi$ and $A_{5}$. Then, we find that the transverse vector part $\hat{A}_{\mu}$ decouples from the scalar parts. In order to eliminate the tachyonic modes of $\hat{A}_{\mu}$, the two coupling parameters $\alpha$ and $\beta$ should satisfy a relation. Combining the restricted condition, we can get a combination parameter as $\gamma=\frac{3}{2}\pm\sqrt{1+12\alpha}$. Only if $\gamma>1/2$, the zero mode of $\hat{A}_{\mu}$ can be localized on the RS-like thick brane. We also investigate the resonant character of the vector part $\hat{A}_{\mu}$ for the general RS-like thick brane with the warp factor $A(z)=-\ln(1+k^2z^2)/2$ by choosing the relative probability method. The result shows that, only for $\gamma>3$, the massive resonant Kaluza-Klein modes can exist. The number of resonant Kaluza-Klein states increases with the combination parameter $\gamma$, and the lifetime of the first resonant state can be long enough as the age of our universe. This indicates that the vector resonances might be considered as one of the candidates of dark matter.

[63]  arXiv:2001.02170 (cross-list from physics.space-ph) [pdf, ps, other]

Title: PIC simulation of a shock tube: Implications for wave transmission in the heliospheric boundary region

Authors: S. Matsukiyo, T. Noumi, G. P. Zank, H. Washimi, T. Hada

Comments: 14 figures, accepted for publication in ApJ

Subjects: Space Physics (physics.space-ph); High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR)

A shock tube problem is solved numerically by using one-dimensional full particle-in-cell simulations under the condition that a relatively tenuous and weakly magnetized plasma is continuously pushed by a relatively dense and strongly magnetized plasma having supersonic relative velocity. A forward and a reverse shock and a contact discontinuity are self-consistently reproduced. The spatial width of the contact discontinuity increases as the angle between the discontinuity normal and ambient magnetic field decreases. The inner structure of the discontinuity shows different profiles between magnetic field and plasma density, or pressure, which is caused by a non-MHD effect of the local plasma. The region between the two shocks is turbulent. The fluctuations in the relatively dense plasma are compressible and propagating away from the contact discontinuity, although the fluctuations in the relatively tenuous plasma contain both compressible and incompressible components. The source of the compressible fluctuations in the relatively dense plasma is in the relatively tenuous plasma. Only compressible fast mode fluctuations generated in the relatively tenuous plasma are transmitted through the contact discontinuity and propagate in the relatively dense plasma. These fast mode fluctuations are steepened when passing the contact discontinuity. This wave steepening and probably other effects may cause the broadening of the wave spectrum in the very local interstellar medium plasma. The results are discussed in the context of the heliospheric boundary region or heliopause.

[64]  arXiv:2001.02174 (cross-list from physics.space-ph) [pdf, other]

Title: MMS Observations of Whistler and Lower Hybrid Drift Waves Associated with Magnetic Reconnection in the Turbulent Magnetosheath

Authors: Vörös Zoltán, Emiliya Yordanova, Daniel B. Graham, Yuri V. Khotyaintsev, Yasuhito Narita

Journal-ref: Journal od Geophysical Research: Space Physics, Volume 124, Isuue 11, pages 8551-8563, year 2019

Subjects: Space Physics (physics.space-ph); Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)

Magnetic reconnection (MR) and the associated concurrently occurring waves have been extensively studied at large-scale plasma boundaries, in quasi-symmetric and asymmetric configurations in the terrestrial magnetotail and at the magnetopause. Recent high-resolution observations by MMS (Magnetospheric Multiscale) spacecraft indicate that MR can occur also in the magnetosheath where the conditions are highly turbulent when the upstream shock geometry is quasi-parallel. The strong turbulent motions make the boundary conditions for evolving MR complicated. In this paper it is demonstrated that the wave observations in localized regions of MR can serve as an additional diagnostic tool reinforcing our capacity for identifying MR events in turbulent plasmas. It is shown that in a close resemblance with MR at large-scale boundaries, turbulent reconnection associated whistler waves occur at separatrix/outflow regions and at the outer boundary of the electron diffusion region, while lower hybrid drift waves are associated with density gradients during the crossing of the current sheet. The lower hybrid drift instability can make the density inhomogeneities rippled. The identification of MR associated waves in the magnetosheath represents also an important milestone for developing a better understanding of energy redistribution and dissipation in turbulent plasmas.

Replacements for Wed, 8 Jan 20

[65]  arXiv:1811.06911 (replaced) [pdf, other]

Title: Reverberation Reveals the Truncated Disc in the Hard State of GX 339-4

Authors: Ra'ad D. Mahmoud, Chris Done, Barbara De Marco

Comments: 18 pages; Accepted to MNRAS

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

[66]  arXiv:1811.09151 (replaced) [pdf, other]

Title: Imprints of Primordial Non-Gaussianity on Gravitational Wave Spectrum

Authors: Caner Unal

Comments: 7 pages, 10 figures, added figures of merit to stress that interferometers can probe nonGaussianity sensitively (fnl~ 0.5)

Journal-ref: Phys. Rev. D 99, 041301 (2019)

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)

[67]  arXiv:1901.00871 (replaced) [pdf, other]

Title: The SPIRITS sample of Luminous Infrared Transients: Uncovering Hidden Supernovae and Dusty Stellar Outbursts in Nearby Galaxies

Authors: Jacob E. Jencson (1), Mansi M. Kasliwal (1), Scott M. Adams (1), Howard E. Bond (2 and 3), Kishalay De (1), Joel Johansson (4), Viraj Karambelkar (5), Ryan M. Lau (1 and 6), Samaporn Tinyanont (1), Stuart D. Ryder (7 and 8), Ann Marie Cody (9), Frank J. Masci (10), John Bally (11), Nadia Blagorodnova (12), Sergio Castellón (13), Christoffer Fremling (1), Robert D. Gehrz (14), George Helou (10), Charles D. Kilpatrick (15), Peter A. Milne (16), Nidia Morrell (13), Daniel A. Perley (17), M. M. Phillips (13), Nathan Smith (16), Schuyler D. van Dyk (10), Robert E. Williams (3 and 15) ((1) California Institute of Technology, (2) Pennsylvania State University, (3) Space Telescope Science Institute, (4) Uppsala University, (5) Indian Institute of Technology Bombay, (6) Japan Aerospace Exploration Agency, (7) Australian Astronomical Observatory, (8) Macquarie University, (9) NASA Ames, (10) Caltech/IPAC, (11) University of Colorado, (12) Radboud University, (13) Las Campanas Observatory, (14) University of Minnesota, (15) UC Santa Cruz, (16) University of Arizona, (17) Liverpool John Moores University)

Comments: 47 pages, 16 figures, published in ApJ

Journal-ref: The Astrophysical Journal 886 (2019) 40

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Astrophysics of Galaxies (astro-ph.GA)

[68]  arXiv:1901.03340 (replaced) [pdf, other]

Title: ARTIST: Fast radiative transfer for large-scale simulations of the epoch of reionisation

Authors: Margherita Molaro, Romeel Davé, Sultan Hassan, Mario G. Santos, Kristian Finlator

Comments: 18 pages, 16 figures, published by MNRAS (14 August 2019)

Journal-ref: 2019MNRAS.489.5594M

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)

[69]  arXiv:1902.01417 (replaced) [pdf, other]

Title: Occurrence Rates of Planets orbiting FGK Stars: Combining Kepler DR25, Gaia DR2 and Bayesian Inference

Authors: Danley C. Hsu, Eric B. Ford, Darin Ragozzine, Keir Ashby

Comments: Published in AJ; 28 pages, 6 figures, 4 tables

Subjects: Earth and Planetary Astrophysics (astro-ph.EP)

[70]  arXiv:1903.06712 (replaced) [pdf, other]

Title: Generalized compactness limit from an arbitrary viewing angle

Authors: Tatsuya Matsumoto, Ehud Nakar, Tsvi Piran

Comments: 12 pages, 6 figures, 3 tables, accepted for publication in MNRAS

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

[71]  arXiv:1905.00431 (replaced) [pdf, other]

Title: The [CII]--SFR correlation in dwarf galaxies across cosmic time

Authors: Alessandro Lupi, Stefano Bovino

Comments: 10 pages, 12 figures; 1 table; accepted for publication by MNRAS

Subjects: Astrophysics of Galaxies (astro-ph.GA)

[72]  arXiv:1905.01238 (replaced) [pdf, other]

Title: Primordial Black Holes as Silver Bullets for New Physics at the Weak Scale

Authors: Gianfranco Bertone, Adam Coogan, Daniele Gaggero, Bradley J. Kavanagh, Christoph Weniger

Comments: 10 pages, 3 figures. Code available at this https URL , archived at this https URL . v2: Matches version published in PRD

Journal-ref: Phys. Rev. D 100, 123013 (2019)

Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE)

[73]  arXiv:1905.01384 (replaced) [pdf, ps, other]

Title: Slip-Back Mapping as a Tracker of Topological Changes in Evolving Magnetic Configurations

Authors: R. Lionello, V. S. Titov, Z. Mikić, J. A. Linker

Comments: To appear in Ap.J

Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

[74]  arXiv:1905.02730 (replaced) [pdf, other]

Title: Continuous gravitational wave from magnetized white dwarfs and neutron stars: possible missions for LISA, DECIGO, BBO, ET detectors

Authors: Surajit Kalita, Banibrata Mukhopadhyay

Comments: Updated version combining original paper (MNRAS 490, 2692-2705 (2019)) and corrections in erratum (MNRAS 491, 4396-4397 (2020))

Journal-ref: MNRAS 490, 2692-2705 (2019); MNRAS 491, 4396-4397 (2020)

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); General Relativity and Quantum Cosmology (gr-qc)

[75]  arXiv:1905.11154 (replaced) [pdf, other]

Title: SKA-Phase 1 sensitivity for synchrotron radio emission from multi-TeV Dark Matter candidates

Authors: J. A. R. Cembranos (UCM-IPARCOS), A. de la Cruz-Dombriz (UCT), V. Gammaldi (IFT-UAM, INFN, SISSA), M. Mendez-Isla (UCT)

Comments: 16 pages, 8 figures. Final version published in Physics of the Dark Universe

Journal-ref: Physics of the Dark Universe, Volume 27, January 2020, 100448

Subjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO)

[76]  arXiv:1905.12182 (replaced) [pdf, other]

Title: Sublunar-Mass Primordial Black Holes from Closed Axion Domain Walls

Authors: Shuailiang Ge

Comments: 10 pages, 6 figures. Match the accepted manuscript

Journal-ref: Physics of the Dark Universe 27 (2020) 100440

Subjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO)

[77]  arXiv:1905.13189 (replaced) [pdf, other]

Title: A Beginner's Guide to Working with Astronomical Data

Authors: Markus Pössel

Comments: 71 pages, 111 figures; revised version for publication in the Open Journal of Astrophysics

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Physics Education (physics.ed-ph)

[78]  arXiv:1906.07683 (replaced) [pdf, other]

Title: An Accurate Fitting Function For Scale-dependent Growth Rate in Hu-Sawicki $f(R)$ Gravity

Authors: Nareg Mirzatuny, Elena Pierpaoli

Comments: 15 pages, 7 figures

Journal-ref: JCAP 1909 (2019) no.09, 066

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)

[79]  arXiv:1907.03102 (replaced) [pdf, other]

Title: Galactic Gamma Ray Background from Interactions of Cosmic Rays

Authors: Sayan Biswas, Nayantara Gupta

Comments: 22 pages, 15 figures

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

[80]  arXiv:1907.06476 (replaced) [pdf, other]

Title: Solar photosphere magnetization

Authors: Véronique Bommier

Comments: 11 pages, 4 figures, resubmitted to Astronomy and Astrophysics, Section Astrophysical Processes

Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

[81]  arXiv:1908.11665 (replaced) [pdf, ps, other]

Title: The impact of AGN feedback on galaxy intrinsic alignments in the Horizon simulations

Authors: Adam Soussana, Nora Elisa Chisari, Sandrine Codis, Ricarda S. Beckmann, Yohan Dubois, Julien Devriendt, Sebastien Peirani, Clotilde Laigle, Christophe Pichon, Adrianne Slyz

Comments: 17 pages, 13 figures, accepted in MNRAS

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); Astrophysics of Galaxies (astro-ph.GA)

[82]  arXiv:1909.03049 (replaced) [pdf, other]

Title: On short GRBs similar to GRB 170817A detected by Fermi GBM

Authors: Tatsuya Matsumoto, Tsvi Piran

Comments: 8 pages, 4 figures, 1 table, accepted for publication in MNRAS

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

[83]  arXiv:1909.08039 (replaced) [pdf, other]

Title: EHT constraint on the ultralight scalar hair of the M87 supermassive black hole

Authors: Pedro V.P. Cunha, Carlos A. R. Herdeiro, Eugen Radu

Comments: 16 pages, 4 figures; v2: small modifications accounting for the referee's feedback; references added

Journal-ref: Universe 2019, 5(12), 220

Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Phenomenology (hep-ph)

[84]  arXiv:1909.09077 (replaced) [pdf, other]

Title: Evidence for a highly opaque large-scale galaxy void at the end of reionization

Authors: Daichi Kashino, Simon J. Lilly, Takatoshi Shibuya, Masami Ouchi, Nobunari Kashikawa

Comments: 16 pages, 12 figures, published in ApJ

Journal-ref: ApJ 888, 6 (2019)

Subjects: Astrophysics of Galaxies (astro-ph.GA)

[85]  arXiv:1910.03590 (replaced) [pdf, other]

Title: Weighing the stellar constituents of the Galactic halo with APOGEE red giant stars

Authors: J. Ted Mackereth, Jo Bovy

Comments: 17 Pages, 11 Figures, Accepted for publication in MNRAS following minor revisions. Code for reproduction of results is available at this https URL

Subjects: Astrophysics of Galaxies (astro-ph.GA)

[86]  arXiv:1910.06335 (replaced) [pdf, other]

Title: Hic sunt dracones: Cartography of the Milky Way spiral arms and bar resonances with Gaia Data Release 2

Authors: S. Khoperskov, O. Gerhard, P. Di Matteo, M. Haywood, D. Katz, S. Khrapov, A. Khoperskov, M. Arnaboldi

Comments: 10 pages, 6 figures, accepted for publication in A&A Letters

Subjects: Astrophysics of Galaxies (astro-ph.GA)

[87]  arXiv:1910.13225 (replaced) [pdf, ps, other]

Title: New perspectives on the TOV equilibrium from a dual null approach

Authors: Alan Maciel, Morgan Le Delliou, José P. Mimoso

Comments: 9 pp, 1 fig

Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE)

[88]  arXiv:1911.08357 (replaced) [pdf, other]

Title: ROME (Radio Observations of Magnetized Exoplanets). II. HD 189733 Does Not Accrete Significant Material from its Exoplanet like a T Tauri Star from A Disk

Authors: Matthew Route (1), Leslie W. Looney (2) ((1) Purdue University, (2) University of Illinois, Urbana-Champaign)

Comments: Accepted by ApJ; 15 pages, 3 tables, 3 figures

Journal-ref: ApJ, 887, 229 (2019)

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP)

[89]  arXiv:1911.11545 (replaced) [pdf, other]

Title: The Forgotten Quadrant Survey. $^{12}$CO and $^{13}$CO (1-0) survey of the Galactic Plane in the range 220°$<l<$240° -2.5°$<b<$0°

Authors: M. Benedettini, S. Molinari, A. Baldeschi, M. T. Beltran, J. Brand, R. Cesaroni, D. Elia, F. Fontani, M. Merello, L. Olmi, S. Pezzuto, K. L. J. Rygl, E. Schisano, L. Testi, A. Traficante

Comments: 16 pages, 17 figures, accepted for publication in Astronomy and Astrophysics

Subjects: Astrophysics of Galaxies (astro-ph.GA)

[90]  arXiv:1912.00387 (replaced) [pdf, other]

Title: Mutual Orbital Inclinations Between Cold Jupiters and Inner Super-Earths

Authors: Kento Masuda, Joshua N. Winn, Hajime Kawahara

Comments: accepted for publication in The Astronomical Journal, 22 pages, 4 figures

Journal-ref: The Astronomical Journal, 159, 38 (2020)

Subjects: Earth and Planetary Astrophysics (astro-ph.EP)

[91]  arXiv:1912.02415 (replaced) [pdf, other]

Title: Modelling Double Neutron Stars: Radio and Gravitational Waves

Authors: Debatri Chattopadhyay, Simon Stevenson, Jarrod R. Hurley, Luca J. Rossi, Chris Flynn

Comments: 25 pages, submitted to MNRAS

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc)

[92]  arXiv:1912.04522 (replaced) [pdf, other]

Title: The Impact of Merging on The Origin of Kinematically Misaligned and Counter-rotating Galaxies in MaNGA

Authors: Song-lin Li, Yong Shi, Dmitry Bizyaev, Christopher Duckworth, Ren-bin Yan, Yan-mei Chen, Long-ji Bing, Jian-hang Chen, Xiao-ling Yu, Rogemar A. Riffel

Comments: 11 pages, 5 figures, submitted to MNRAS. Has been refereed and requires major revision

Subjects: Astrophysics of Galaxies (astro-ph.GA)

[93]  arXiv:1912.04839 (replaced) [pdf, ps, other]

Title: Homogeneous Analysis of Globular Clusters from the APOGEE Survey with the BACCHUS Code. II. The Southern Clusters and Overview

Authors: Szabolcs Mészáros, Thomas Masseron, D. A. García-Hernández, Carlos Allende Prieto, Timothy C. Beers, Dmitry Bizyaev, Drew Chojnowski, Roger E. Cohen, Katia Cunha, Flavia Dell'Agli, Garrett Ebelke, José G. Fernández-Trincado, Peter Frinchaboy, Doug Geisler, Sten Hasselquist, Fred Hearty, Jon Holtzman, Jennifer Johnson, Richard R. Lane, Ivan Lacerna, Penelopé Longa-Peña, Steven R. Majewski, Sarah L. Martell, Dante Minniti, David Nataf, David L. Nidever, Kaike Pan, Ricardo P. Schiavon, Matthew Shetrone, Verne V. Smith, Jennifer S. Sobeck, Guy S. Stringfellow, László Szigeti, Baitian Tang, John C. Wilson, Olga Zamora

Comments: Accepted for publication in MNRAS, 31 pages, 24 figures, 7 tables. Various typos are fixed

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)

[94]  arXiv:1912.07294 (replaced) [pdf, other]

Title: Effects of close binary evolution on the main-sequence morphology of young star clusters

Authors: Chen Wang, Norbert Langer, Abel Schootemeijer, Norberto Castro, Sylvia Adscheid, Pablo Marchant, Ben Hastings

Comments: 12 pages, 5 figures, 1 animation, published in ApJL, 2020, 888, L12

Journal-ref: ApJL 888 (2020) L12

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)

[95]  arXiv:1912.09490 (replaced) [pdf, other]

Title: The evolution of radio jets across cosmic time

Authors: Andrew J. Griffin (1), Cedric G. Lacey (1), Violeta Gonzalez-Perez (1,2,3), Claudia del P. Lagos (4,5,6) ((1) ICC Durham, (2) ICG Portsmouth, (3) Lancaster, (4) ICRAR, UWA, (5) ASTRO 3D, (6) DAWN, Copenhagen)

Comments: MNRAS submitted

Subjects: Astrophysics of Galaxies (astro-ph.GA)

[96]  arXiv:1912.09683 (replaced) [pdf, ps, other]

Title: Anisotropic Response Measurements of ZnWO$_4$ Scintillators to Neutrons for Developing the Direction-Sensitive Dark Matter Detector

Authors: Juan W. Pedersen, Hiroyuki Sekiya, Koichi Ichimura

Subjects: Instrumentation and Detectors (physics.ins-det); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Experiment (hep-ex)

[97]  arXiv:1912.09740 (replaced) [pdf, other]

Title: A Walking Dilaton Inflation

Authors: Hiroyuki Ishida, Shinya Matsuzaki

Comments: 10 pages, 1 figure; references and footnotes added

Subjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)

[98]  arXiv:1912.10213 (replaced) [pdf, other]

Title: A search for the origin of the interstellar comet 2I/Borisov

Authors: Coryn A.L. Bailer-Jones, Davide Farnocchia, Quanzhi Ye, Karen J. Meech, Marco Micheli

Comments: 7 pages; accepted to A&A

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)

[99]  arXiv:1912.10841 (replaced) [pdf, other]

Title: Wideband 67-116 GHz receiver development for ALMA Band 2

Authors: P. Yagoubov, T. Mroczkowski, V. Belitsky, D. Cuadrado-Calle, F. Cuttaia, G. A. Fuller, J.-D. Gallego, A. Gonzalez, K. Kaneko, P. Mena, R. Molina, R. Nesti, V. Tapia, F. Villa, M. Beltran, F. Cavaliere, J. Ceru, G. E. Chesmore, K. Coughlin, C. De Breuck, M. Fredrixon, D. George, H. Gibson, J. Golec, A. Josaitis, F. Kemper, M. Kotiranta, I. Lapkin, I. Lopez-Fernandez, G. Marconi, S. Mariotti, W. McGenn, J. McMahon, A. Murk, F. Pezzotta, N. Phillips, N. Reyes, S. Ricciardi, M. Sandri, M. Strandberg, L. Terenzi, L. Testi, B. Thomas, Y. Uzawa, D. Vigano, N. Wadefalk

Comments: 23 pages, accepted for publication in A&A on 20 Dec 2019. This version incorporates further edits and grid-free plots

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Instrumentation and Detectors (physics.ins-det)

[100]  arXiv:1912.13316 (replaced) [pdf, other]

Title: MIRACLES: atmospheric characterization of directly imaged planets and substellar companions at 4-5 micron. I. Photometric analysis of $β$ Pic b, HIP 65426 b, PZ Tel B and HD 206893 B

Authors: Tomas Stolker, Sascha P. Quanz, Kamen O. Todorov, Jonas Kühn, Paul Mollière, Michael R. Meyer, Thayne Currie, Sebastian Daemgen, Baptiste Lavie

Comments: 25 pages, 15 figures, accepted for publication in A&A

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)

[101]  arXiv:1912.13400 (replaced) [pdf, ps, other]

Title: Binary stars: a cheat sheet

Authors: John Southworth

Comments: 6 pages, 1 figure. Invited contribution to the conference "Stars and their variability observed from space - Celebrating the 5th anniversary of BRITE-Constellation", Vienna, Austria, 19-23 August 2019, eds C. Neiner, W. Weiss, D. Baade, E. Griffin, C. Lovekin and A. Moffat

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP)

[102]  arXiv:2001.00595 (replaced) [pdf, other]

Title: Modeling the uncertainties of solar-system ephemerides for robust gravitational-wave searches with pulsar timing arrays

Authors: M. Vallisneri, S. R. Taylor, J. Simon, W. M. Folkner, R. S. Park, C. Cutler, J. A. Ellis, T. J. W. Lazio, S. J. Vigeland, K. Aggarwal, Z. Arzoumanian, P. T. Baker, A. Brazier, P. R. Brook, S. Burke-Spolaor, S. Chatterjee, J. M. Cordes, N. J. Cornish, F. Crawford, H. T. Cromartie, K. Crowter, M. DeCesar, P. B. Demorest, T. Dolch, R. D. Ferdman, E. C. Ferrara, E. Fonseca, N. Garver-Daniels, P. Gentile, D. Good, J. S. Hazboun, A. M. Holgado, E. A. Huerta, K. Islo, R. Jennings, G. Jones, M. L. Jones, D. L. Kaplan, L. Z. Kelley, J. S. Key, M. T. Lam, L. Levin, D. R. Lorimer, J. Luo, R. S. Lynch, D. R. Madison, M. A. McLaughlin, S. T. McWilliams, C. M. F. Mingarelli, C. Ng, D. J. Nice, T. T. Pennucci, N. S. Pol, S. M. Ransom, P. S. Ray, X. Siemens, R. Spiewak, I. H. Stairs, D. R. Stinebring, K. Stovall, et al. (4 additional authors not shown)

Comments: Fixed typo in author list. Code that supports all calculations and figures is available at github.com/nanograv/11yr_stochastic_analysis/tree/master/bayesephem

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Instrumentation and Methods for Astrophysics (astro-ph.IM); General Relativity and Quantum Cosmology (gr-qc)

[103]  arXiv:2001.00598 (replaced) [pdf, other]

Title: ZTF Early Observations of Type Ia Supernovae II: First Light, the Initial Rise, and Time to Reach Maximum Brightness

Authors: A. A. Miller, Y. Yao, M. Bulla, C. Pankow, E. C. Bellm, S. B. Cenko, R. Dekany, C. Fremling, M. J. Graham, T. Kupfer, R. R. Laher, A. A. Mahabal, F. J. Masci, P. E. Nugent, R. Riddle, B. Rusholme, R. M. Smith, D. L. Shupe, J. van Roestel, S. R. Kulkarni

Comments: 29 pages, 16 figures; submitted to ApJ; v2 - minor typos corrected

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

[104]  arXiv:2001.01209 (replaced) [pdf, other]

Title: Dark Matter in CCDs at Modane (DAMIC-M) : A silicon detector apparatus searching for low-energy physics processes

Authors: Steven Juhyung Lee, Ben Kilminster, Anna Macchiolo

Comments: Proceedings to be submitted to JINST for IPRD19 conference

Subjects: Instrumentation and Detectors (physics.ins-det); Instrumentation and Methods for Astrophysics (astro-ph.IM); High Energy Physics - Experiment (hep-ex)

[105]  arXiv:2001.01484 (replaced) [pdf, other]

Title: $^{14}$N/$^{15}$N isotopic ratio in CH$_3$CN of Titan's atmosphere measured with ALMA

Authors: Takahiro Iino, Hideo Sagawa, Takashi Tsukagoshi

Comments: To be published in ApJ

Subjects: Earth and Planetary Astrophysics (astro-ph.EP)

[106]  arXiv:2001.01563 (replaced) [pdf, other]

Title: Understanding galaxy formation and evolution through an all-sky submillimetre spectroscopic survey

Authors: Mattia Negrello, Matteo Bonato, Zhen-Yi Cai, Helmut Dannerbauer, Gianfranco De Zotti, Jacques Delabrouille, Douglas Scott

Comments: 17 pages, 7 figures, submitted to PASA

Subjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)

[107]  arXiv:2001.01670 (replaced) [pdf, other]

Title: The Strikingly Metal-Rich Halo of the Sombrero Galaxy

Authors: Roger E. Cohen (1), Paul Goudfrooij (1), Matteo Correnti (1), Oleg Y. Gnedin (2), William E. Harris (3), Rupali Chandar (4), Thomas H. Puzia (5), Ruben Sanchez-Janssen (6) ((1) STScI, (2) U. Michigan, (3) McMaster University, (4) U. Toledo, (5) PUC, (6) STFC UK Astronomy Tech. Centre, Royal Observatory, Edinburgh)

Comments: ApJ accepted

Subjects: Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)

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