RAS_WEB (Page 4,538)

Accurate mass and radius determinations of a cool subdwarf in an eclipsing binary. (arXiv:1903.02897v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Rebassa_Mansergas_A/0/1/0/all/0/1">Alberto Rebassa-Mansergas</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Parsons_S/0/1/0/all/0/1">Steven G. Parsons</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dhillon_V/0/1/0/all/0/1">Vikram S. Dhillon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ren_J/0/1/0/all/0/1">Juanjuan Ren</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Littlefair_S/0/1/0/all/0/1">Stuart P. Littlefair</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Marsh_T/0/1/0/all/0/1">Thomas R. Marsh</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Torres_S/0/1/0/all/0/1">Santiago Torres</a> Cool subdwarfs are metal-poor low-mass stars that formed during the early stages of the evolution of our Galaxy. Because they are relatively rare in the vicinity of the Sun, we know of few cool subdwarfs in the solar neighbourhood, and none with both the mass and the radius accurately determined. This hampers our understanding of stars at the low-mass end of the main-sequence. Here weRead More →

A Search for Cosmic-ray Proton Anisotropy with the Fermi Large Area Telescope. (arXiv:1903.02905v1 [astro-ph.HE]) The <a href="http://arxiv.org/find/astro-ph/1/au:+Collaboration_Fermi_LAT/0/1/0/all/0/1">Fermi-LAT Collaboration</a> The Fermi Large Area Telescope (LAT) has amassed a large data set of primary cosmic-ray protons throughout its mission. The LAT’s wide field of view and full-sky survey capabilities make it an excellent instrument for studying cosmic-ray anisotropy. As a space-based survey instrument, the LAT is sensitive to anisotropy in both right ascension and declination, while ground-based observations only measure the anisotropy in right ascension. We present the results of the first ever proton anisotropy search using Fermi LAT. The data set uses eight years of dataRead More →

Exploring the role of X-ray reprocessing and irradiation in the anomalous bright optical outbursts of A0538-66. (arXiv:1903.02918v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Ducci_L/0/1/0/all/0/1">L. Ducci</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mereghetti_S/0/1/0/all/0/1">S. Mereghetti</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hryniewicz_K/0/1/0/all/0/1">K. Hryniewicz</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Santangelo_A/0/1/0/all/0/1">A. Santangelo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Romano_P/0/1/0/all/0/1">P. Romano</a> In 1981, the Be/X-ray binary (Be/XRB) A0538-66 showed outbursts characterized by high peak luminosities in the X-ray and optical bands. The optical outbursts were qualitatively explained as X-ray reprocessing in a gas cloud surrounding the binary system. Since then, further important information about A0538-66 have been obtained, and sophisticated photoionization codes have been developed to calculate the radiation emerging from a gas nebula illuminated by a central X-ray source. In the lightRead More →

High density of active galactic nuclei in the outskirts of distant galaxy clusters. (arXiv:1903.02919v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Koulouridis_E/0/1/0/all/0/1">E. Koulouridis</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bartalucci_I/0/1/0/all/0/1">I. Bartalucci</a> We present a study of the distribution of X-ray detected active galactic nuclei (AGN) in the five most massive, $M_{500}^{SZ}>10^{14} M_{odot}$ , and distant, z$sim$1, galaxy clusters in the textit{Planck} and South Pole Telescope (SPT)textit{} surveys. The spatial and thermodynamic individual properties of each cluster have been defined with unprecedented accuracy at this redshift using deep X-ray observations. This is an essential property of our sample in order to precisely determine the $R_{500}^{Y_{textrm x}}$ radius of the clusters. For our purposes, we computed theRead More →

Compact multi-fringe interferometry with sub-picometer precision. (arXiv:1903.02945v1 [astro-ph.IM]) <a href="http://arxiv.org/find/astro-ph/1/au:+Isleif_K/0/1/0/all/0/1">Katharina-Sophie Isleif</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Heinzel_G/0/1/0/all/0/1">Gerhard Heinzel</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mehmet_M/0/1/0/all/0/1">Moritz Mehmet</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gerberding_O/0/1/0/all/0/1">Oliver Gerberding</a> Deep frequency modulation interferometry combines optical minimalism with multi-fringe readout, precision however is key for applications such as optical gradiometers for satellite geodesy or as dimensional sensor for ground-based gravity experiments. We present a single-component interferometer smaller than a cubic inch. Two of these are compared to each other to demonstrate tilt and displacement measurements with a precision of less than $20,mathrm{nrad}/sqrt{mathrm{Hz}}$ and $1,mathrm{pm}/sqrt{mathrm{Hz}}$ at frequencies below $1,mathrm{Hz}$. Deep frequency modulation interferometry combines optical minimalism with multi-fringe readout, precision however is key for applications suchRead More →

Supermassive black holes and dark halo from the Bose-condensed dark matter. (arXiv:1903.02986v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Morikawa_M/0/1/0/all/0/1">M. Morikawa</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Takahashi_S/0/1/0/all/0/1">S. Takahashi</a> Most of the galaxies harbor supermassive Black Holes (SMBH) in their center. Some of them are observed in very high redshifts. We explore the possibility that SMBH form from the coherent waves of Bose-Einstein condensate (BEC) which are supposed to form the dark matter. We first study the isotropic and anisotropic collapses of BEC. We find the BEC wave can easily collapse to form SMBH but the realistic amount of angular momentum completely prevents the collapse. We further explore the Axion case with attractive interaction andRead More →

Effect of nonlinearity between density and curvature perturbations on the primordial black hole formation. (arXiv:1903.02994v1 [astro-ph.CO]) <a href="http://arxiv.org/find/astro-ph/1/au:+Kawasaki_M/0/1/0/all/0/1">Masahiro Kawasaki</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nakatsuka_H/0/1/0/all/0/1">Hiromasa Nakatsuka</a> We study the effect of the nonlinear relation between density and curvature perturbations on the formation of PBHs. By calculating the variance and skewness of the density perturbation we derive the non-Gaussian property. As a criterion for PBH formation, the compaction function is used and it is found that larger curvature perturbations are required due to the nonlinear effect. We estimate the PBH abundance based on the Press-Schechter formalism with non-Gaussian probability density function during Radiation dominated era. It is found that theRead More →

Direct Detection of WIMP Dark Matter: Concepts and Status. (arXiv:1903.03026v1 [astro-ph.CO]) <a href="http://arxiv.org/find/astro-ph/1/au:+Schumann_M/0/1/0/all/0/1">Marc Schumann</a> The existence of dark matter as evidenced by numerous indirect observations is one of the most important indications that there must be physics beyond the Standard Model of particle physics. This article reviews the concepts of direct detection of dark matter in the form of Weakly Interacting Massive Particles (WIMPs) in ultra-sensitive detectors located in underground laboratories, discusses the expected signatures, detector concepts, and how the stringent low-background requirements are achieved. Finally, it summarizes the current status of the field and provides an outlook on the years to come. The existenceRead More →

STROBE-X: X-ray Timing and Spectroscopy on Dynamical Timescales from Microseconds to Years. (arXiv:1903.03035v1 [astro-ph.IM]) <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:+Arzoumanian_Z/0/1/0/all/0/1">Zaven Arzoumanian</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ballantyne_D/0/1/0/all/0/1">David Ballantyne</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bozzo_E/0/1/0/all/0/1">Enrico Bozzo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Brandt_S/0/1/0/all/0/1">Soren Brandt</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Brenneman_L/0/1/0/all/0/1">Laura Brenneman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chakrabarty_D/0/1/0/all/0/1">Deepto Chakrabarty</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Christophersen_M/0/1/0/all/0/1">Marc Christophersen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+DeRosa_A/0/1/0/all/0/1">Alessandra DeRosa</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Feroci_M/0/1/0/all/0/1">Marco Feroci</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gendreau_K/0/1/0/all/0/1">Keith Gendreau</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Goldstein_A/0/1/0/all/0/1">Adam Goldstein</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hartmann_D/0/1/0/all/0/1">Dieter Hartmann</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hernanz_M/0/1/0/all/0/1">Margarita Hernanz</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jenke_P/0/1/0/all/0/1">Peter Jenke</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kara_E/0/1/0/all/0/1">Erin Kara</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Maccarone_T/0/1/0/all/0/1">Tom Maccarone</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+McDonald_M/0/1/0/all/0/1">Michael McDonald</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nowak_M/0/1/0/all/0/1">Michael Nowak</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Phlips_B/0/1/0/all/0/1">Bernard Phlips</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Remillard_R/0/1/0/all/0/1">Ron Remillard</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Stevens_A/0/1/0/all/0/1">Abigail Stevens</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tomsick_J/0/1/0/all/0/1">John Tomsick</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Watts_A/0/1/0/all/0/1">Anna Watts</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wilson_Hodge_C/0/1/0/all/0/1">Colleen Wilson-Hodge</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wood_K/0/1/0/all/0/1">Kent Wood</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zane_S/0/1/0/all/0/1">Silvia Zane</a> (STROBE-X Science Working Group) We present the Spectroscopic Time-ResolvingRead More →

Studying the Evolution of Warm Dust Encircling BD +20 307 Using SOFIA. (arXiv:1903.03041v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Thompson_M/0/1/0/all/0/1">Maggie A. Thompson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Weinberger_A/0/1/0/all/0/1">Alycia J. Weinberger</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Keller_L/0/1/0/all/0/1">Luke Keller</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Arnold_J/0/1/0/all/0/1">Jessica A. Arnold</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Stark_C/0/1/0/all/0/1">Christopher Stark</a> The small class of known stars with unusually warm, dusty debris disks is a key sample to probe in order to understand cascade models and extreme collisions that likely lead to the final configurations of planetary systems. Because of its extreme dustiness and small radius, the disk of BD +20 307 has a short predicted collision time and is therefore an interesting target in which to look for changes in dust quantity andRead More →

Discrete Cosmological Models in the Brans-Dicke Theory of Gravity. (arXiv:1903.03043v1 [gr-qc]) <a href="http://arxiv.org/find/gr-qc/1/au:+Durk_J/0/1/0/all/0/1">Jessie Durk</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Clifton_T/0/1/0/all/0/1">Timothy Clifton</a> We consider the problem of building inhomogeneous cosmological models in scalar-tensor theories of gravity. This starts by splitting the field equations of these theories into constraint and evolution equations, and then proceeds by identifying exact solutions to the constraints. We find exact, closed form expressions for geometries that correspond to the initial data for cosmological models containing regular arrays of point-like masses. These solutions extend similar methods that have recently been applied to Einstein’s equations, and provides sufficient initial conditions to perform numerical integration of the evolution equations.Read More →

Periodic Q-mode modulation in PSR J1825$-$0935 (PSR B1822$-$09). (arXiv:1903.01989v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Yan_W/0/1/0/all/0/1">W. M. Yan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Manchester_R/0/1/0/all/0/1">R. N. Manchester</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wang_N/0/1/0/all/0/1">N. Wang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yuan_J/0/1/0/all/0/1">J. P. Yuan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wen_Z/0/1/0/all/0/1">Z. G. Wen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lee_K/0/1/0/all/0/1">K. J. Lee</a> PSR J1825$-$0935 (PSR B1822$-$09) switches between radio-quiet (Q-mode) and radio-bright (B-mode) modes. The Q-mode is known to have a periodic fluctuation that modulates both the interpulse and the main pulse with the same period. Earlier investigators argued that the periodic Q-mode modulation is associated with drifting subpulses. We report on single-pulse observations of PSR J1825$-$0935 that were made using the Parkes 64-m radio telescope with a central frequency of 1369 MHz. TheRead More →

Modelling annual and orbital variations in the scintillation of the relativistic binary PSR J1141$-$6545. (arXiv:1903.01990v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Reardon_D/0/1/0/all/0/1">D. J. Reardon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Coles_W/0/1/0/all/0/1">W. A. Coles</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hobbs_G/0/1/0/all/0/1">G. Hobbs</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ord_S/0/1/0/all/0/1">S. Ord</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kerr_M/0/1/0/all/0/1">M. Kerr</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bailes_M/0/1/0/all/0/1">M. Bailes</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bhat_N/0/1/0/all/0/1">N. D. R. Bhat</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Krishnan_V/0/1/0/all/0/1">V. Venkatraman Krishnan</a> We have observed the relativistic binary pulsar PSR J1141$-$6545 over a period of $sim$6 years using the Parkes 64 m radio telescope, with a focus on modelling the diffractive intensity scintillations to improve the accuracy of the astrometric timing model. The long-term scintillation, which shows orbital and annual variations, allows us to measure parameters that are difficult to measure withRead More →

Is patchy reionization an obstacle in detecting the primordial gravitational wave signal?. (arXiv:1903.01994v1 [astro-ph.CO]) <a href="http://arxiv.org/find/astro-ph/1/au:+Mukherjee_S/0/1/0/all/0/1">Suvodip Mukherjee</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Paul_S/0/1/0/all/0/1">Sourabh Paul</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Choudhury_T/0/1/0/all/0/1">Tirthankar Roy Choudhury</a> The large-scale CMB B-mode polarization is the direct probe to the low frequency primordial gravitational wave signal. However, unambiguous measurement of this signal requires a precise understanding of the possible contamination. One such potential contamination arises from the patchiness in the spatial distribution of free electrons during the epoch of reionization. We estimate the B-mode power spectrum due to patchy reionization using a combination of emph{photon-conserving} semi-numerical simulation and analytical calculation, and compare its strength with the primordial B-mode signal. EvenRead More →

Enlarging habitable zones around binary stars in hostile environments. (arXiv:1903.01995v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Wootton_B/0/1/0/all/0/1">Bethany A. Wootton</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Parker_R/0/1/0/all/0/1">Richard J. Parker</a> (University of Sheffield, UK) Habitable zones are regions around stars where large bodies of liquid water can be sustained on a planet or satellite. As many stars form in binary systems with non-zero eccentricity, the habitable zones around the component stars of the binary can overlap and be enlarged when the two stars are at periastron (and less often when the stars are at apastron). We perform N-body simulations of the evolution of dense star-forming regions and show that binary systems where the component stars originallyRead More →

Black hole mass estimation for Active Galactic Nuclei from a new angle. (arXiv:1903.01996v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Baron_D/0/1/0/all/0/1">Dalya Baron</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Menard_B/0/1/0/all/0/1">Brice M&#xe9;nard</a> The scaling relations between supermassive black holes and their host galaxy properties are of fundamental importance in the context black hole-host galaxy co-evolution throughout cosmic time. In this work, we use a novel algorithm that identifies smooth trends in complex datasets and apply it to a sample of 2,000 type I active galactic nuclei (AGN) spectra. We detect a sequence in emission line shapes and strengths which reveals a correlation between the narrow L([OIII])/L(H$beta$) line ratio and the width of the broad H$alpha$. This scalingRead More →

Deep Learning at Scale for Gravitational Wave Parameter Estimation of Binary Black Hole Mergers. (arXiv:1903.01998v1 [gr-qc]) <a href="http://arxiv.org/find/gr-qc/1/au:+Shen_H/0/1/0/all/0/1">Hongyu Shen</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Huerta_E/0/1/0/all/0/1">E. A. Huerta</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Zhao_Z/0/1/0/all/0/1">Zhizhen Zhao</a> We present the first application of deep learning at scale to do gravitational wave parameter estimation of binary black hole mergers that describe a 4-D signal manifold, i.e., black holes whose spins are aligned or anti-aligned, and which evolve on quasi-circular orbits. We densely sample this 4-D signal manifold using over three hundred thousand simulated waveforms. In order to cover a broad range of astrophysically motivated scenarios, we synthetically enhance this waveform dataset to ensure that our deep learningRead More →

RELICS: Reionization Lensing Cluster Survey. (arXiv:1903.02002v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Coe_D/0/1/0/all/0/1">Dan Coe</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Salmon_B/0/1/0/all/0/1">Brett Salmon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bradac_M/0/1/0/all/0/1">Marusa Bradac</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bradley_L/0/1/0/all/0/1">Larry D. Bradley</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sharon_K/0/1/0/all/0/1">Keren Sharon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zitrin_A/0/1/0/all/0/1">Adi Zitrin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Acebron_A/0/1/0/all/0/1">Ana Acebron</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cerny_C/0/1/0/all/0/1">Catherine Cerny</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cibirka_N/0/1/0/all/0/1">Nathalia Cibirka</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Strait_V/0/1/0/all/0/1">Victoria Strait</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Paterno_Mahler_R/0/1/0/all/0/1">Rachel Paterno-Mahler</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mahler_G/0/1/0/all/0/1">Guillaume Mahler</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Avila_R/0/1/0/all/0/1">Roberto J. Avila</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ogaz_S/0/1/0/all/0/1">Sara Ogaz</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Huang_K/0/1/0/all/0/1">Kuang-Han Huang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pelliccia_D/0/1/0/all/0/1">Debora Pelliccia</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Stark_D/0/1/0/all/0/1">Daniel P. Stark</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mainali_R/0/1/0/all/0/1">Ramesh Mainali</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Oesch_P/0/1/0/all/0/1">Pascal A. Oesch</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Trenti_M/0/1/0/all/0/1">Michele Trenti</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Carrasco_D/0/1/0/all/0/1">Daniela Carrasco</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dawson_W/0/1/0/all/0/1">William A. Dawson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rodney_S/0/1/0/all/0/1">Steven A. Rodney</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Strolger_L/0/1/0/all/0/1">Louis-Gregory Strolger</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Riess_A/0/1/0/all/0/1">Adam G. Riess</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jones_C/0/1/0/all/0/1">Christine Jones</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Frye_B/0/1/0/all/0/1">Brenda L. Frye</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Czakon_N/0/1/0/all/0/1">Nicole G. Czakon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Umetsu_K/0/1/0/all/0/1">Keiichi Umetsu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vulcani_B/0/1/0/all/0/1">BenedettaRead More →

The Milky Way bar/bulge in proper motions: a 3D view from VIRAC & Gaia. (arXiv:1903.02003v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Clarke_J/0/1/0/all/0/1">Jonathan P. Clarke</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wegg_C/0/1/0/all/0/1">Christopher Wegg</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gerhard_O/0/1/0/all/0/1">Ortwin Gerhard</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Smith_L/0/1/0/all/0/1">Leigh C. Smith</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lucas_P/0/1/0/all/0/1">Phil W. Lucas</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wylie_S/0/1/0/all/0/1">Shola M. Wylie</a> We have derived absolute proper motions of the entire Galactic bulge region from VIRAC and Gaia. We present these as both integrated on-sky maps and, after isolating standard candle red clump (RC) stars, as a function of distance using RC magnitude as a proxy. These data provide a new global, 3-dimensional view of the Milky Way barred bulge kinematics. We find a gradient in the mean longitudinalRead More →

Formation of short-period planets by disk migration. (arXiv:1903.02004v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Carrera_D/0/1/0/all/0/1">Daniel Carrera</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ford_E/0/1/0/all/0/1">Eric B. Ford</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Izidoro_A/0/1/0/all/0/1">Andre Izidoro</a> Protoplanetary disks are thought to be truncated at orbital periods of around 10 days. Therefore, origin of rocky short period planets with $P < 10$ days is a puzzle. We propose that many of these planets may form through the Type-I migration of planets locked into a chain of mutual mean motion resonances. We ran N-body simulations of planetary embryos embedded in a protoplanetary disk. The embryos experienced gravitational scatterings, collisions, disk torques, and dampening of orbital eccentricity and inclination. We then modelled Kepler observations ofRead More →