RAS_WEB (Page 4,539)

Sub-second variability in black-hole X-ray binary jets. (arXiv:1903.02005v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Vincentelli_F/0/1/0/all/0/1">Federico M. Vincentelli</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Casella_P/0/1/0/all/0/1">Piergiorgio Casella</a> In the last 10 years multi-wavelength fast variability studies of low mass X-ray binaries have shown a dramatic development. A key discovery was the detection of O-IR sub-second fluctuations in two black-hole transients, lagging the X-rays by $approx$0.1 s. This demonstrated how the fluctuations observed in the inflow could be transferred to the jet, allowing therefore also to study in a completely new way the physical processes which take place at the base of the jet. In this paper we review the latest developments of the study of jetsRead More →

High-Energy Neutrinos from Blazar Flares and Implications of TXS 0506+056. (arXiv:1903.02006v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Oikonomou_F/0/1/0/all/0/1">Foteini Oikonomou</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Murase_K/0/1/0/all/0/1">Kohta Murase</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Petropoulou_M/0/1/0/all/0/1">Maria Petropoulou</a> Motivated by the observation of a $>290$ TeV muon neutrino by IceCube, coincident with a $sim$6 month-long $gamma$-ray flare of the blazar TXS 0506+056, and an archival search which revealed $13 pm 5$ further, lower-energy neutrinos in the direction of the source in 2014-2015, we discuss the likely contribution of blazars to the diffuse high-energy neutrino intensity, the implications for neutrino emission from TXS 0506+056 based on multi-wavelength observations of the source, and a multi-zone model that allows for sufficient neutrino emission so asRead More →

Cosmic web anisotropy is the primary indicator of halo assembly bias. (arXiv:1903.02007v1 [astro-ph.CO]) <a href="http://arxiv.org/find/astro-ph/1/au:+Ramakrishnan_S/0/1/0/all/0/1">Sujatha Ramakrishnan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Paranjape_A/0/1/0/all/0/1">Aseem Paranjape</a> (IUCAA), <a href="http://arxiv.org/find/astro-ph/1/au:+Hahn_O/0/1/0/all/0/1">Oliver Hahn</a> (OCA), <a href="http://arxiv.org/find/astro-ph/1/au:+Sheth_R/0/1/0/all/0/1">Ravi K. Sheth</a> (UPenn/ICTP) The internal properties of dark matter haloes correlate with the large-scale halo clustering strength at fixed halo mass $-$ an effect known as assembly bias $-$ and are also strongly affected by the local, non-linear cosmic web. Characterising a halo’s local web environment by its tidal anisotropy $alpha$ at scales $sim4$ x the halo radius, we demonstrate that these multi-scale correlations represent two distinct statistical links: one between the internal property and $alpha$, and the otherRead More →

Transverse kinematics of the Galactic bar-bulge from VVV and Gaia. (arXiv:1903.02008v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Sanders_J/0/1/0/all/0/1">Jason L. Sanders</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Smith_L/0/1/0/all/0/1">Leigh Smith</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Evans_N/0/1/0/all/0/1">N. Wyn Evans</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lucas_P/0/1/0/all/0/1">Philip Lucas</a> We analyse the kinematics of the Galactic bar-bulge using proper motions from the ESO public survey Vista Variables in the Via Lactea (VVV) and the second Gaia data release. Gaia has provided some of the first absolute proper motions within the bulge and the near-infrared VVV multi-epoch catalogue complements Gaia in highly-extincted low-latitude regions. We discuss the relative-to-absolute calibration of the VVV proper motions using Gaia. Along lines of sight spanning $-10Read More →

The pattern speed of the Milky Way bar from transverse velocities. (arXiv:1903.02009v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Sanders_J/0/1/0/all/0/1">Jason L. Sanders</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Smith_L/0/1/0/all/0/1">Leigh Smith</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Evans_N/0/1/0/all/0/1">N. Wyn Evans</a> We use the continuity equation to derive a method for measuring the pattern speed of the Milky Way’s bar from proper motion data. The method has minimal assumptions but requires complete coverage of the non-axisymmetric component in two of the three Galactic coordinates. We apply our method to the proper motion data from a combination of Gaia DR2 and VISTA Variables in the Via Lactea (VVV) to measure the pattern speed of the bar as $Omega_mathrm{p}=(41pm 3),mathrm{km,s^{-1},kpc^{-1}}$. This puts the corotationRead More →

No Run Gravity. (arXiv:1903.02010v1 [astro-ph.CO]) <a href="http://arxiv.org/find/astro-ph/1/au:+Linder_E/0/1/0/all/0/1">Eric V. Linder</a> Considering the dark energy/gravity landscape if next generation surveys of galaxies, cosmic microwave background radiation, and gravitational waves do not find clear modification of gravity, we develop No Run Gravity as a counterexample to the conclusion that this would imply general relativity with an expansion history described by an equation of state $w(z)$. No Run Gravity is a cubic Horndeski theory with a constant Planck mass, no gravitational slip, and no modification of gravitational waves, but a rich phenomenology beyond $w(z)$. We calculate the evolution of gravitational strength, sound speed, and cosmic growth within the theoryRead More →

A code for robust astrometric solution of astronomical images. (arXiv:1903.02015v1 [astro-ph.IM]) <a href="http://arxiv.org/find/astro-ph/1/au:+Ofek_E/0/1/0/all/0/1">Eran O. Ofek</a> I present a software tool for solving the astrometry of astronomical images. The code puts emphasis on robustness against failures for correctly matching the sources in the image to a reference catalog, and on the stability of the solutions over the field of view (e.g., using orthogonal polynomials for the fitted transformation). The code was tested on over 50,000 images from various sources, including the Palomar Transient Factory (PTF) and the Zwicky Transient Facility (ZTF). The tested images equally represent low and high Galactic latitude fields and exhibit failure/bad-solution rateRead More →

A six year image-subtraction light curve of SN 2010jl. (arXiv:1903.02016v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Ofek_E/0/1/0/all/0/1">E. O. Ofek</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zackay_B/0/1/0/all/0/1">B. Zackay</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gal_Yam_A/0/1/0/all/0/1">A. Gal-Yam</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sollerman_J/0/1/0/all/0/1">J. Sollerman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fransson_C/0/1/0/all/0/1">C. Fransson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fremling_C/0/1/0/all/0/1">C. Fremling</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kulkarni_S/0/1/0/all/0/1">S. R. Kulkarni</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nugent_P/0/1/0/all/0/1">P. E. Nugent</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yaron_O/0/1/0/all/0/1">O. Yaron</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kasliwal_M/0/1/0/all/0/1">M. M. Kasliwal</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Masci_F/0/1/0/all/0/1">F. Masci</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Laher_R/0/1/0/all/0/1">R. Laher</a> SN2010jl was a luminous Type IIn supernova (SN), detected in radio, optical, X-ray and hard X-rays. Here we report on its six year R- and g-band light curves obtained using the Palomar Transient Factory. The light curve was generated using a pipeline based on the proper image subtraction method and we discuss the algorithmRead More →

Axion Dark Matter Search with Interferometric Gravitational Wave Detectors. (arXiv:1903.02017v1 [hep-ph]) <a href="http://arxiv.org/find/hep-ph/1/au:+Nagano_K/0/1/0/all/0/1">Koji Nagano</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Fujita_T/0/1/0/all/0/1">Tomohiro Fujita</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Michimura_Y/0/1/0/all/0/1">Yuta Michimura</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Obata_I/0/1/0/all/0/1">Ippei Obata</a> Axion dark matter differentiates the phase velocities of the circular-polarized photons. In this Letter, a scheme to measure the phase difference by using a linear optical cavity is proposed. If the scheme is applied to the Fabry-P’erot arm of Advanced LIGO-like (Cosmic-Explorer-like) gravitational wave detector, the potential sensitivity to the axion-photon coupling constant, $g_{text{a}gamma}$, reaches $g_{text{a}gamma} simeq 8times10^{-13}$ GeV$^{-1}, (4 times 10^{-14}$ GeV$^{-1})$ at the axion mass $m simeq 3times 10^{-13}$ eV ($2times10^{-15}$ eV) and remains at around this sensitivity for 3Read More →

HI galaxies with little star formation: an abundance of LIERs. (arXiv:1903.02024v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Parkash_V/0/1/0/all/0/1">Vaishali Parkash</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Brown_M/0/1/0/all/0/1">Michael J.I. Brown</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jarrett_T/0/1/0/all/0/1">T. H. Jarrett</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fraser_McKelvie_A/0/1/0/all/0/1">Amelia Fraser-McKelvie</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cluver_M/0/1/0/all/0/1">M.E. Cluver</a> We present a sample of 91 HI galaxies with little or no star formation and discuss the analysis of the integral field unit (IFU) spectra of 28 of these galaxies. We identified HI galaxies from the HI Parkes All-Sky Survey Catalog (HICAT) with Wide-field Infrared Survey Explorer (WISE) colours consistent with low specific star formation (< 10$^{-10.4}$ yr$^{-1}$), and obtained optical IFU spectra with the Wide-Field Spectrograph (WiFeS). Visual inspection of the PanSTARRS, Dark Energy Survey,Read More →

Linear bias forecasts for emission line cosmological surveys. (arXiv:1903.02030v1 [astro-ph.CO]) <a href="http://arxiv.org/find/astro-ph/1/au:+Merson_A/0/1/0/all/0/1">Alexander Merson</a> (JPL/IPAC), <a href="http://arxiv.org/find/astro-ph/1/au:+Smith_A/0/1/0/all/0/1">Alex Smith</a> (IRFU, CEA), <a href="http://arxiv.org/find/astro-ph/1/au:+Benson_A/0/1/0/all/0/1">Andrew Benson</a> (Carnegie), <a href="http://arxiv.org/find/astro-ph/1/au:+Wang_Y/0/1/0/all/0/1">Yun Wang</a> (IPAC), <a href="http://arxiv.org/find/astro-ph/1/au:+Baugh_C/0/1/0/all/0/1">Carlton Baugh</a> (ICC) We forecast the linear bias for H${rm alpha}$-emitting galaxies at high redshift. To simulate a Euclid-like and a WFIRST-like survey we place galaxies into a large-volume dark matter halo lightcone by sampling a library of luminosity-dependent halo occupation distributions, which is constructed using a physically motivated galaxy formation model. We calibrate the dust attenuation in the lightcones such that they are able to reproduce the H${rm alpha}$ luminosity function or the H${rm alpha}$ cumulativeRead More →

Inflation meets neutrinos. (arXiv:1903.02036v1 [astro-ph.CO]) <a href="http://arxiv.org/find/astro-ph/1/au:+Barenboim_G/0/1/0/all/0/1">Gabriela Barenboim</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Denton_P/0/1/0/all/0/1">Peter B. Denton</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Oldengott_I/0/1/0/all/0/1">Isabel M. Oldengott</a> Constraints on inflationary models typically assume only the standard models of cosmology and particle physics. By extending the neutrino sector to include a new interaction with a light scalar mediator ($m_{phi}sim$MeV), it is possible to relax these constraints, in particular via opening up regions of the parameter space of the spectral index $n_s$. These new interactions can be probed at IceCube via interactions of astrophysical neutrinos with the Cosmic Neutrino Background for nearly all of the relevant parameter space. Constraints on inflationary models typically assume only the standard modelsRead More →

Classification of shift-symmetric Horndeski theories and hairy black holes. (arXiv:1903.02055v1 [gr-qc]) <a href="http://arxiv.org/find/gr-qc/1/au:+Saravani_M/0/1/0/all/0/1">Mehdi Saravani</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Sotiriou_T/0/1/0/all/0/1">Thomas P. Sotiriou</a> No-hair theorems for scalar-tensor theories imply that the trivial scalar field configuration is the unique configuration around stationary black hole spacetimes. The most basic assumption in these theorems is that a constant scalar configuration is actually admissible. In this paper, we classify shift-symmetric Horndeski theories according to whether or not they admit the trivial scalar configuration as a solution and under which conditions. Local Lorentz symmetry and the presence of a linear coupling between the scalar field and Gauss-Bonnet invariant plays feature prominently in this classification. WeRead More →

Complex Rotational Modulation of Rapidly Rotating M-Stars Observed with TESS. (arXiv:1903.02061v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Zhan_Z/0/1/0/all/0/1">Z. Zhan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gunther_M/0/1/0/all/0/1">M. N. G&#xfc;nther</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rappaport_S/0/1/0/all/0/1">S. Rappaport</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Olah_K/0/1/0/all/0/1">K. Ol&#xe1;h</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mann_A/0/1/0/all/0/1">A. Mann</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Levine_A/0/1/0/all/0/1">A. M. Levine</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Winn_J/0/1/0/all/0/1">J. Winn</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dai_F/0/1/0/all/0/1">F. Dai</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zhou_G/0/1/0/all/0/1">G. Zhou</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Huang_C/0/1/0/all/0/1">Chelsea X. Huang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bouma_L/0/1/0/all/0/1">L.G. Bouma</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ireland_M/0/1/0/all/0/1">M.J. Ireland</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ricker_G/0/1/0/all/0/1">G. Ricker</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vanderspek_R/0/1/0/all/0/1">R. Vanderspek</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Latham_D/0/1/0/all/0/1">D. Latham</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Seager_S/0/1/0/all/0/1">S. Seager</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jenkins_J/0/1/0/all/0/1">J. Jenkins</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Caldwell_D/0/1/0/all/0/1">D. A. Caldwell</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Doty_J/0/1/0/all/0/1">J. Doty</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Essack_Z/0/1/0/all/0/1">Z. Essack</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Furesz_G/0/1/0/all/0/1">G. Furesz</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Leidos_M/0/1/0/all/0/1">M. E. R. Leidos</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rowden_P/0/1/0/all/0/1">P. Rowden</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Smith_J/0/1/0/all/0/1">J. C. Smith</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Stassun_K/0/1/0/all/0/1">K. G. Stassun</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vezie_M/0/1/0/all/0/1">M. Vezie</a> We have searched for short periodicities inRead More →

The semicentennial binary system PSR J2032+4127 at periastron: X-ray photometry, optical spectroscopy and SPH modelling. (arXiv:1903.02084v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Coe_M/0/1/0/all/0/1">M. J. Coe</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Okazaki_A/0/1/0/all/0/1">A.T. Okazaki</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Steele_I/0/1/0/all/0/1">I.A. Steele</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ng_C/0/1/0/all/0/1">C.-Y. Ng</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ho_W/0/1/0/all/0/1">Wynn C.G. Ho</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lyne_A/0/1/0/all/0/1">A. G. Lyne</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Stappers_B/0/1/0/all/0/1">B. Stappers</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Johnson_T/0/1/0/all/0/1">T.J. Johnson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ray_P/0/1/0/all/0/1">Paul S. Ray</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kerr_M/0/1/0/all/0/1">M. Kerr</a> X-ray photometry and optical spectra are presented covering the periastron passage of the highly-eccentric, ~50 year binary system PSR J2032+4127 in November 2017. This system consists of a 143 ms pulsar in orbit around a massive OB star, MT 91-213. The data show dramatic changes during the encounter as the pulsar wind collided withRead More →

Neutrino self-interaction and MSW effects on the supernova neutrino-process. (arXiv:1903.02086v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Ko_H/0/1/0/all/0/1">Heamin Ko</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cheoun_M/0/1/0/all/0/1">Myung-Ki Cheoun</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ha_E/0/1/0/all/0/1">Eunja Ha</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kusakabe_M/0/1/0/all/0/1">Motohiko Kusakabe</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hayakawa_T/0/1/0/all/0/1">Takehito Hayakawa</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sasaki_H/0/1/0/all/0/1">Hirokazu Sasaki</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kajino_T/0/1/0/all/0/1">Toshitaka Kajino</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hashimoto_M/0/1/0/all/0/1">Masa-aki Hashimoto</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ono_M/0/1/0/all/0/1">Masaomi Ono</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Usang_M/0/1/0/all/0/1">Mark D. Usang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chiba_S/0/1/0/all/0/1">Satoshi Chiba</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nakamura_K/0/1/0/all/0/1">Ko Nakamura</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tolstov_A/0/1/0/all/0/1">Alexey Tolstov</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nomoto_K/0/1/0/all/0/1">Ken&#x27;ichi Nomoto</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kawano_T/0/1/0/all/0/1">Toshihiko Kawano</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mathews_G/0/1/0/all/0/1">Grant J. Mathews</a> We investigate nuclear abundances produced from the neutrino ($nu$)-process in supernova explosions. For the first time, we have calculated the flux propagation including both its modification by $nu$ self-interaction ($nu$-SI) near the $nu$-sphere and the Mikheyev-Smirnov-Wolfenstein (MSW) effect in the outer O-Ne-Mg layer. TheRead More →

Probing pulsar scattering between 120 and 280 MHz with the MWA. (arXiv:1903.02087v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Kirsten_F/0/1/0/all/0/1">F. Kirsten</a> (Chalmers University), <a href="http://arxiv.org/find/astro-ph/1/au:+Bhat_N/0/1/0/all/0/1">N. D. R. Bhat</a> (ICRAR Curtin), <a href="http://arxiv.org/find/astro-ph/1/au:+Meyers_B/0/1/0/all/0/1">B. W. Meyers</a> (ICRAR Curtin), <a href="http://arxiv.org/find/astro-ph/1/au:+Macquart_J/0/1/0/all/0/1">J.-P. Macquart</a> (ICRAR Curtin), <a href="http://arxiv.org/find/astro-ph/1/au:+Tremblay_S/0/1/0/all/0/1">S. E. Tremblay</a> (ICRAR Curtin), <a href="http://arxiv.org/find/astro-ph/1/au:+Ord_S/0/1/0/all/0/1">S. M. Ord</a> (CSIRO) The high sensitivity and wide frequency coverage of the Murchison Widefield Array allow for the measurement of the spectral scaling of the pulsar scattering timescale, $alpha$, from a single observation. Here we present three case studies targeted at bright, strongly scattered pulsars J0534+2200 (the Crab pulsar), J0835-4510 (the Vela pulsar) and J0742-2822. We measure the scattering spectral indicesRead More →

The CH4 cycles on Pluto over seasonal and astronomical timescales. (arXiv:1903.02096v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Bertrand_T/0/1/0/all/0/1">T. Bertrand</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Forget_F/0/1/0/all/0/1">F. Forget</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Umurhan_O/0/1/0/all/0/1">O.M. Umurhan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Moore_J/0/1/0/all/0/1">J.M. Moore</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Young_L/0/1/0/all/0/1">L.A. Young</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Protopapa_S/0/1/0/all/0/1">S. Protopapa</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Grundy_W/0/1/0/all/0/1">W.M. Grundy</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Schmitt_B/0/1/0/all/0/1">B. Schmitt</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dhingra_R/0/1/0/all/0/1">R.D. Dhingra</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Binzel_R/0/1/0/all/0/1">R.P. Binzel</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Earle_A/0/1/0/all/0/1">A.M. Earle</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cruikshank_D/0/1/0/all/0/1">D.P. Cruikshank</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Stern_S/0/1/0/all/0/1">S.A. Stern</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Weaver_H/0/1/0/all/0/1">H.A. Weaver</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ennico_K/0/1/0/all/0/1">K. Ennico</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Olkin_C/0/1/0/all/0/1">C.B. Olkin</a> New Horizons observations suggest that CH4 on Pluto has a complex history, involving reservoirs of different composition, thickness and stability controlled by volatile processes occurring on different timescales. In order to interpret these observations, we use a Pluto volatile transport model able to simulate theRead More →

Two-dimensional non-LTE ion{O}{I} 777,nm line formation in radiation hydrodynamics simulations of Cepheid atmospheres. (arXiv:1903.02109v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Vasilyev_V/0/1/0/all/0/1">V. Vasilyev</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Amarsi_A/0/1/0/all/0/1">A. M. Amarsi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ludwig_H/0/1/0/all/0/1">H.-G. Ludwig</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lemasle_B/0/1/0/all/0/1">B. Lemasle</a> Oxygen abundance measurements are important for understanding stellar structure and evolution. Measured in Cepheids, they further provide clues on the metallicity gradient and chemo-dynamical evolution in the Galaxy. However, most of the abundance analyses of Cepheids to date have been based on one-dimensional (1D) hydrostatic model atmospheres. Here, we test the validity of this approach for the key oxygen abundance diagnostic, the ion{O}{I} $777,mathrm{nm}$~triplet lines. We carry out 2D non-LTE radiative transfer clculations across two different 2DRead More →

Efficient self-resonance instability from axions. (arXiv:1903.02119v1 [astro-ph.CO]) <a href="http://arxiv.org/find/astro-ph/1/au:+Fukunaga_H/0/1/0/all/0/1">Hayato Fukunaga</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kitajima_N/0/1/0/all/0/1">Naoya Kitajima</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Urakawa_Y/0/1/0/all/0/1">Yuko Urakawa</a> It was recently shown that a coherent oscillation of an axion can cause an efficient parametric resonance, leading to a prominent emission of the gravitational waves (GWs). In this paper, conducting the Floquet analysis, we investigate the parametric resonance instability, which potentially triggers the emission of the GWs from axions. Such a resonance instability takes place, when the time evolution of the background field significantly deviates from the harmonic oscillation. Therefore, the resonance instability cannot be described by the Mathieu equation, whose stability/instability chart is well known. In thisRead More →