RAS_WEB (Page 4,429)

A Fundamental Plane for Gamma-Ray Pulsars. (arXiv:1904.01765v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Kalapotharakos_C/0/1/0/all/0/1">Constantinos Kalapotharakos</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Harding_A/0/1/0/all/0/1">Alice K. Harding</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kazanas_D/0/1/0/all/0/1">Demosthenes Kazanas</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wadiasingh_Z/0/1/0/all/0/1">Zorawar Wadiasingh</a> We show that the $gamma$-ray pulsar observables, i.e., their total $gamma$-ray luminosity, $L_{gamma}$, spectrum cut-off energy, $epsilon_{rm cut}$, stellar surface magnetic field, $B_{star}$, and spin-down power $dot{mathcal{E}}$, obey a relation of the form $L_{gamma}=f(epsilon_{rm cut},B_{star},dot{mathcal{E}})$, which represents a 3D plane in their 4D log-space. Fitting the data of the 88 pulsars of the second Fermi pulsar catalog, we show this relation to be $L_{gamma}propto epsilon_{rm cut}^{1.18pm 0.24}B_{star}^{0.17pm 0.05}dot{mathcal{E}}^{0.41pm 0.08}$, a pulsar fundamental plane (FP). We show that the observed FP is remarkably close toRead More →

Primordial Black Hole Microlensing: The Einstein Crossing Time Distribution. (arXiv:1904.01771v1 [astro-ph.CO]) <a href="http://arxiv.org/find/astro-ph/1/au:+Lu_J/0/1/0/all/0/1">Jessica R. Lu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lam_C/0/1/0/all/0/1">Casey Y. Lam</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Medford_M/0/1/0/all/0/1">Michael Medford</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dawson_W/0/1/0/all/0/1">William Dawson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Golovich_N/0/1/0/all/0/1">Nathan Golovich</a> Gravitational microlensing is one of the few means of finding primordial black holes (PBHs), if they exist. Recent LIGO detections of 30 Msun black holes have re-invigorated the search for PBHs in the 10-100 Msun mass regime. Unfortunately, individual PBH microlensing events cannot easily be distinguished from stellar lensing events from photometry alone. However, the distribution of microlensing timescales (tE, the Einstein radius crossing time) can be analyzed in a statistical sense using models of the MilkyRead More →

Astro2020: From Stars to Compact Objects: The Initial-Final Mass Relation. (arXiv:1904.01773v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Lu_J/0/1/0/all/0/1">Jessica R. Lu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lam_C/0/1/0/all/0/1">Casey Lam</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dawson_W/0/1/0/all/0/1">Will Dawson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gaudi_B/0/1/0/all/0/1">B. Scott Gaudi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Golovich_N/0/1/0/all/0/1">Nathan Golovich</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Medford_M/0/1/0/all/0/1">Michael Medford</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Abdurrahman_F/0/1/0/all/0/1">Fatima Abdurrahman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Beaton_R/0/1/0/all/0/1">Rachael L. Beaton</a> One of the key phases of stellar evolution that remains poorly understood is stellar death. We lack a predictive model for how a star of a given mass explodes and what kind of remnant it leaves behind (i.e. the initial-final mass relation, IFMR). Progress has been limited due to the difficulty in finding and weighing black holes and neutron stars in large numbers. Technological advances thatRead More →

Magnetic field vector ambiguity resolution in a quiescent prominence observed on two following days. (arXiv:1904.01816v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Kalewicz_T/0/1/0/all/0/1">T. Kalewicz</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bommier_V/0/1/0/all/0/1">V. Bommier</a> % context {Magnetic field vector measurements are always ambiguous, i.e., two or more field vectors are solutions of the observed polarisation.} % aims {The aim of the present paper is to solve the ambiguity by comparing the ambiguous field vectors obtained in the same prominence observed on two following days. The effect of the solar rotation is to modify the scattering angle of the prominence radiation, which modifies the symmetry of the ambiguous solutions. This method, which is a kind of tomography, wasRead More →

Phantom singularities and their quantum fate: general relativity and beyond. (arXiv:1904.01836v1 [gr-qc]) <a href="http://arxiv.org/find/gr-qc/1/au:+Bouhmadi_Lopez_M/0/1/0/all/0/1">Mariam Bouhmadi-L&#xf3;pez</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Kiefer_C/0/1/0/all/0/1">Claus Kiefer</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Martin_Moruno_P/0/1/0/all/0/1">Prado Mart&#xed;n-Moruno</a> Cosmological observations allow the possibility that dark energy is caused by phantom fields. These fields typically lead to the occurrence of singularities in the late Universe. We review here the status of phantom singularities and their possible avoidance in a quantum theory of gravity. We first introduce phantom energy and discuss its behavior in cosmology. We then list the various types of singularities that can occur from its presence. We also discuss the possibility that phantom behavior is mimicked by an alternative theory ofRead More →

SN 2016B a.k.a ASASSN-16ab: a transitional type II supernova. (arXiv:1904.01844v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Dastidar_R/0/1/0/all/0/1">Raya Dastidar</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Misra_K/0/1/0/all/0/1">Kuntal Misra</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Singh_M/0/1/0/all/0/1">Mridweeka Singh</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sahu_D/0/1/0/all/0/1">D. K. Sahu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pastorello_A/0/1/0/all/0/1">A. Pastorello</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gangopadhyay_A/0/1/0/all/0/1">Anjasha Gangopadhyay</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tomasella_L/0/1/0/all/0/1">L. Tomasella</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Benetti_S/0/1/0/all/0/1">S. Benetti</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Terreran_G/0/1/0/all/0/1">G. Terreran</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sanwal_P/0/1/0/all/0/1">Pankaj Sanwal</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kumar_B/0/1/0/all/0/1">Brijesh Kumar</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Singh_A/0/1/0/all/0/1">Avinash Singh</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kumar_B/0/1/0/all/0/1">Brajesh Kumar</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Anupama_G/0/1/0/all/0/1">G. C. Anupama</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pandey_S/0/1/0/all/0/1">S. B. Pandey</a> We present photometry, polarimetry and spectroscopy of the Type II supernova ASASSN-16ab/SN 2016B in PGC 037392. The photometric and spectroscopic follow-up commenced about two weeks after shock breakout and continued until nearly six months. The light curve of SN 2016B exhibits intermediate properties between those ofRead More →

The evolutionary status of Cataclysmic Variables: Eclipse modelling of 15 systems. (arXiv:1904.01888v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+McAllister_M/0/1/0/all/0/1">M. McAllister</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Littlefair_S/0/1/0/all/0/1">S. P. Littlefair</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Parsons_S/0/1/0/all/0/1">S. G. Parsons</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dhillon_V/0/1/0/all/0/1">V. S. Dhillon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Marsh_T/0/1/0/all/0/1">T. R. Marsh</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gaensicke_B/0/1/0/all/0/1">B. T. Gaensicke</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Breedt_E/0/1/0/all/0/1">E. Breedt</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Copperwheat_C/0/1/0/all/0/1">C. Copperwheat</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Green_M/0/1/0/all/0/1">M. J. Green</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Knigge_C/0/1/0/all/0/1">C. Knigge</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sahman_D/0/1/0/all/0/1">D. I. Sahman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dyer_M/0/1/0/all/0/1">M. J. Dyer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kerry_P/0/1/0/all/0/1">P. Kerry</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ashley_R/0/1/0/all/0/1">R. P. Ashley</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Irawati_P/0/1/0/all/0/1">P. Irawati</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rattanasoon_S/0/1/0/all/0/1">S. Rattanasoon</a> We present measurements of the component masses in 15 Cataclysmic Variables (CVs) – 6 new estimates and 9 improved estimates. We provide new calibrations of the relationship between superhump period excess and mass ratio, andRead More →

Kinetic Inductance Detectors and readout electronics for the OLIMPO experiment. (arXiv:1904.01890v1 [astro-ph.IM]) <a href="http://arxiv.org/find/astro-ph/1/au:+Paiella_A/0/1/0/all/0/1">A. Paiella</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Battistelli_E/0/1/0/all/0/1">E. S. Battistelli</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Castellano_M/0/1/0/all/0/1">M. G. Castellano</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Colantoni_I/0/1/0/all/0/1">I. Colantoni</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Columbro_F/0/1/0/all/0/1">F. Columbro</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Coppolecchia_A/0/1/0/all/0/1">A. Coppolecchia</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+DAlessandro_G/0/1/0/all/0/1">G. D&#x27;Alessandro</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bernardis_P/0/1/0/all/0/1">P. de Bernardis</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gordon_S/0/1/0/all/0/1">S. Gordon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lamagna_L/0/1/0/all/0/1">L. Lamagna</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mani_H/0/1/0/all/0/1">H. Mani</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Masi_S/0/1/0/all/0/1">S. Masi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mauskopf_P/0/1/0/all/0/1">P. Mauskopf</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pettinari_G/0/1/0/all/0/1">G. Pettinari</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Piacentini_F/0/1/0/all/0/1">F. Piacentini</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Presta_G/0/1/0/all/0/1">G. Presta</a> Kinetic Inductance Detectors (KIDs) are superconductive low$-$temperature detectors useful for astrophysics and particle physics. We have developed arrays of lumped elements KIDs (LEKIDs) sensitive to microwave photons, optimized for the four horn-coupled focal planes of the OLIMPO balloon-borne telescope, working in theRead More →

The short wavelength instrument for the polarization explorer balloon-borne experiment: Polarization modulation issues. (arXiv:1904.01891v1 [astro-ph.IM]) <a href="http://arxiv.org/find/astro-ph/1/au:+Columbro_F/0/1/0/all/0/1">F. Columbro</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Battistelli_E/0/1/0/all/0/1">E. S. Battistelli</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Coppolecchia_A/0/1/0/all/0/1">A. Coppolecchia</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+DAlessandro_G/0/1/0/all/0/1">G. D&#x27;Alessandro</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bernardis_P/0/1/0/all/0/1">P. de Bernardis</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lamagna_L/0/1/0/all/0/1">L. Lamagna</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Masi_S/0/1/0/all/0/1">S. Masi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pagano_L/0/1/0/all/0/1">L. Pagano</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Paiella_A/0/1/0/all/0/1">A. Paiella</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Piacentini_F/0/1/0/all/0/1">F. Piacentini</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Presta_G/0/1/0/all/0/1">G. Presta</a> In this paper we investigate the impact of using a polarization modulator in the Short Wavelenght Instrument for the Polarization Explorer (SWIPE) of the Large Scale Polarization Explorer (LSPE). The experiment is optimized to measure the linear polarization of the Cosmic Microwave Background at large angular scales during a circumpolar long-duration stratospheric balloon mission, andRead More →

Validation of the neutron monitor yield function using data from AMS-02 experiment, 2011–2017. (arXiv:1904.01929v1 [physics.space-ph]) <a href="http://arxiv.org/find/physics/1/au:+Koldobskiy_S/0/1/0/all/0/1">Sergey A. Koldobskiy</a>, <a href="http://arxiv.org/find/physics/1/au:+Bindi_V/0/1/0/all/0/1">Veronica Bindi</a>, <a href="http://arxiv.org/find/physics/1/au:+Corti_C/0/1/0/all/0/1">Claudio Corti</a>, <a href="http://arxiv.org/find/physics/1/au:+Kovaltsov_G/0/1/0/all/0/1">Gennady A. Kovaltsov</a>, <a href="http://arxiv.org/find/physics/1/au:+Usoskin_I/0/1/0/all/0/1">Ilya G. Usoskin</a> The newly published spectra of protons and helium over time directly measured in space by the AMS-02 experiment for the period 2011–2017 provide a unique opportunity to calibrate ground-based neutron monitors (NMs). Here, calibration of several stable sealevel NMs (Inuvik, Apatity, Oulu, Newark, Moscow, Hermanus, Athens) was performed using these spectra. Four modern NM yield functions were verified: Mi13 (Mishev et al., 2013), Ma16 (Mangeard et al., 2016), CM12 (Caballero-Lopez & Moraal,Read More →

Development of Spherical Proportional Counter for light WIMP search within NEWS-G collaboration. (arXiv:1904.01944v1 [physics.ins-det]) <a href="http://arxiv.org/find/physics/1/au:+Dastgheibi_Fard_A/0/1/0/all/0/1">Ali Dastgheibi-Fard</a>, <a href="http://arxiv.org/find/physics/1/au:+Geribier_G/0/1/0/all/0/1">Gilles Geribier</a> (on behalf of the NEWS-G Collaboration) The Spherical gaseous detector (or Spherical Proportional Counter, SPC) has a broad range of applications. In this work, we will focus on the light WIMP Dark Matter particle search, that is, below a few GeV. The NEWS-G collaboration operates a 60 cm diameter detector at Modane underground laboratory (LSM). Running the detector at 3 b of Neon gas, some competitive limits have been set down to 0.5 GeV WIMP mass thanks to an energy threshold of around 100 eV.Read More →

High-precision analysis of binary stars with planets. I. Searching for condensation temperature trends in the HD 106515 system. (arXiv:1904.01955v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Saffe_C/0/1/0/all/0/1">C. Saffe</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jofre_E/0/1/0/all/0/1">E. Jofre</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Miquelarena_P/0/1/0/all/0/1">P. Miquelarena</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Arancibia_M/0/1/0/all/0/1">M. Jaque Arancibia</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Flores_M/0/1/0/all/0/1">M. Flores</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lopez_F/0/1/0/all/0/1">F. M. Lopez</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Collado_A/0/1/0/all/0/1">A. Collado</a> We explore the probable chemical signature of planet formation in the remarkable binary system HD 106515. The A star hosts a massive long-period planet with 9 MJup detected by radial velocity. We also refine stellar and planetary parameters by using non-solar-scaled opacities when modeling the stars. Methods. We carried out a simultaneous determination of stellar parameters and abundances, by applying for theRead More →

Storms or Systematics? The changing secondary eclipse depth of WASP-12b. (arXiv:1904.01973v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Hooton_M/0/1/0/all/0/1">Matthew J. Hooton</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mooij_E/0/1/0/all/0/1">Ernst J. W. de Mooij</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Watson_C/0/1/0/all/0/1">Christopher A. Watson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gibson_N/0/1/0/all/0/1">Neale P. Gibson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Galindo_Guil_F/0/1/0/all/0/1">Francisco J. Galindo-Guil</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Clavero_R/0/1/0/all/0/1">Rosa Clavero</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Merritt_S/0/1/0/all/0/1">Stephanie R. Merritt</a> WASP-12b is one of the most well-studied transiting exoplanets, as its highly-inflated radius and its 1.1 day orbit around a G0-type star make it an excellent target for atmospheric categorisation through observation during its secondary eclipse. We present two new secondary eclipse observations of WASP-12b, acquired a year apart with the Wide Field Camera on the Isaac Newton Telescope (INT) and the IO:O instrumentRead More →

HST resolves stars in a tiny body falling on the dwarf galaxy DDO 68. (arXiv:1904.01986v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Annibali_F/0/1/0/all/0/1">F. Annibali</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Bellazzini_M/0/1/0/all/0/1">M. Bellazzini</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Correnti_M/0/1/0/all/0/1">M. Correnti</a> (2), <a href="http://arxiv.org/find/astro-ph/1/au:+Sacchi_E/0/1/0/all/0/1">E. Sacchi</a> (2), <a href="http://arxiv.org/find/astro-ph/1/au:+Tosi_M/0/1/0/all/0/1">M. Tosi</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Cignoni_M/0/1/0/all/0/1">M. Cignoni</a> (3), <a href="http://arxiv.org/find/astro-ph/1/au:+Aloisi_A/0/1/0/all/0/1">A. Aloisi</a> (2), <a href="http://arxiv.org/find/astro-ph/1/au:+Calzetti_D/0/1/0/all/0/1">D. Calzetti</a> (4), <a href="http://arxiv.org/find/astro-ph/1/au:+Ciotti_L/0/1/0/all/0/1">L. Ciotti</a> (5), <a href="http://arxiv.org/find/astro-ph/1/au:+Cusano_F/0/1/0/all/0/1">F. Cusano</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Lee_J/0/1/0/all/0/1">J. Lee</a> (6), <a href="http://arxiv.org/find/astro-ph/1/au:+Nipoti_C/0/1/0/all/0/1">C. Nipoti</a> (5) ((1) INAF-Astrophysics and Space Science Observatory, Bologna, Italy (2) Space Telescope Science Institute, Baltimore, USA (3) Dipartimento di Fisica, Universita&#x27; di Pisa, Italy (4) Department of Astronomy, University of Massachusetts-Amherst, USA (5) Dipartimento di Fisica e Astronomia, Universita&#x27; di Bologna, ItalyRead More →

On the origin of 7Be isotopic records in a Calcium, Aluminium, -rich inclusion. (arXiv:1904.01992v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Mishra_R/0/1/0/all/0/1">Ritesh Kumar Mishra</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Marhas_K/0/1/0/all/0/1">Kuljeet Kaur Marhas</a> A prime question in the formation and early evolution of the Solar system studies is to discern the source(s) of short-lived now extinct nuclides and to determine the ab-initio isotopic composition of our Solar System (ref. 1). The proposed genesis of a short-lived now extinct radionuclide,10Be, by spallation reactions of carbon and oxygen led to the hypothesis of enhanced irradiation in the early Solar system (ref. 2-8). An alternative scenario of production of 10Be (t1/2 =1.386 +- 0.016 million years (ref.9)) byRead More →

Energetic Particles in Halos of Star Forming Galaxies. (arXiv:1904.01997v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Rephaeli_Y/0/1/0/all/0/1">Yoel Rephaeli</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sadeh_S/0/1/0/all/0/1">Sharon Sadeh</a> Quantitative modeling of the spectro-spatial distributions of energetic electrons and protons in galactic halos is needed in order to determine their interactions with the local plasma and radiation fields, and also to estimate their residual spectral densities in intracluster and intergalactic environments. We develop a semi-analytic approach for calculating the particle distributions in the halo based on a detailed diffusion model for particle propagation from acceleration sites and interactions in the galactic disk. Important overall normalization of our models is based on results from detailed modeling in the GalacticRead More →

Extended main-sequence turnoffs in the double cluster $h$ and $chi$ Persei: The complex role of stellar rotation. (arXiv:1904.02005v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Li_C/0/1/0/all/0/1">Chengyuan Li</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sun_W/0/1/0/all/0/1">Weijia Sun</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Grijs_R/0/1/0/all/0/1">Richard de Grijs</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Deng_L/0/1/0/all/0/1">Licai Deng</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wang_K/0/1/0/all/0/1">Kun Wang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cordoni_G/0/1/0/all/0/1">Giacomo Cordoni</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Milone_A/0/1/0/all/0/1">Antonino P. Milone</a> Using {sl Gaia} Data Release 2 photometry, we report the detection of extended main-sequence turnoff (eMSTO) regions in the color–magnitude diagrams (CMDs) of the $sim 14$ Myr-old double clusters $h$ and $chi$ Persei (NGC 869 and NGC 884). We find that stars with masses below $sim$1.3 $M_{odot}$ in both $h$ and $chi$ Persei populate narrow main sequences (MSs), while more massive stars defineRead More →

Astro2020 Science White Paper: A New Era for X-ray Lensing Studies of Quasars and Galaxies. (arXiv:1904.02018v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Chartas_G/0/1/0/all/0/1">George Chartas</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Krawczynski_H/0/1/0/all/0/1">Henric Krawczynski</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pooley_D/0/1/0/all/0/1">David Pooley</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mushotzky_R/0/1/0/all/0/1">Richard F. Mushotzky</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ptak_A/0/1/0/all/0/1">Andrew J. Ptak</a> Current X-ray observations and simulations show that gravitational lensing can be used to infer the structure near the event horizons of black holes, constrain the dynamics and evolution of black-hole accretion and outflows, test general relativity in the strong-gravity regime and place constraints on the evolution of dark matter in the lensing galaxies. These science goals currently cannot be achieved in a statistically large sample of z = 0.5 – 5Read More →