RAS_WEB (Page 4,114)

2D chemical evolution model: the impact of galactic disc asymmetries on azimuthal chemical abundance variations. (arXiv:1811.11196v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Spitoni_E/0/1/0/all/0/1">E. Spitoni</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cescutti_G/0/1/0/all/0/1">G. Cescutti</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Minchev_I/0/1/0/all/0/1">I. Minchev</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Matteucci_F/0/1/0/all/0/1">F. Matteucci</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Aguirre_V/0/1/0/all/0/1">V. Silva Aguirre</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Martig_M/0/1/0/all/0/1">M. Martig</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bono_G/0/1/0/all/0/1">G. Bono</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chiappini_C/0/1/0/all/0/1">C. Chiappini</a> Galactic disc chemical evolution models generally ignore azimuthal surface density variation that can introduce chemical abundance azimuthal gradients. Recent observations, however, have revealed chemical abundance changes with azimuth in the gas and stellar components of both the Milky Way and external galaxies.To quantify the effects of spiral arm density fluctuations on the azimuthal variations of the oxygen and iron abundances in disc galaxies.Read More →

The challenge of detecting intracluster filaments with Faraday Rotation. (arXiv:1811.11198v1 [astro-ph.CO]) <a href="http://arxiv.org/find/astro-ph/1/au:+Locatelli_N/0/1/0/all/0/1">Nicola Locatelli</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vazza_F/0/1/0/all/0/1">Franco Vazza</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dominguez_Fernandez_P/0/1/0/all/0/1">Paola Dom&#xed;nguez-Fern&#xe1;ndez</a> The detection of filaments in the cosmic web will be crucial to distinguish between the possible magnetogenesis scenarios and future large polarization surveys will be able to shed light on their magnetization level. In this work, we use numerical simulations of galaxy clusters to investigate their possible detection. We compute the Faraday Rotation signal in intracluster filaments and compare it to its surrounding environment. We find that the expected big improvement in sensitivity with the SKA-MID will in principle allow the detection of a largeRead More →

Seeing Higher-Dimensional Grand Unification In Primordial Non-Gaussianities. (arXiv:1811.11200v1 [hep-ph]) <a href="http://arxiv.org/find/hep-ph/1/au:+Kumar_S/0/1/0/all/0/1">Soubhik Kumar</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Sundrum_R/0/1/0/all/0/1">Raman Sundrum</a> The observed low-energy values of the SU(3)x SU(2)x U(1) gauge couplings, extrapolated via the minimal Standard Model Renormalization Group evolution, hint at the exciting possibility of a Grand Unified Theory (GUT) at M_U sim 10^14 GeV — a scale, however, too high to probe directly via collider searches. Fortunately, since the Hubble scale H can be as high as 5 x 10^13 GeV sim M_U during the inflationary era, such GUT scale states can be cosmologically produced at that time and leave direct on-shell signatures such as their masses andRead More →

Planck’s dusty GEMS. VI. Multi-J CO excitation and interstellar medium conditions in dusty starburst galaxies at z=2-4. (arXiv:1811.11215v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Canameras_R/0/1/0/all/0/1">R. Canameras</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yang_C/0/1/0/all/0/1">C. Yang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nesvadba_N/0/1/0/all/0/1">N. P. H. Nesvadba</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Beelen_A/0/1/0/all/0/1">A. Beelen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kneissl_R/0/1/0/all/0/1">R. Kneissl</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Koenig_S/0/1/0/all/0/1">S. Koenig</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Floch_E/0/1/0/all/0/1">E. Le Floc&#x27;h</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Limousin_M/0/1/0/all/0/1">M. Limousin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Malhotra_S/0/1/0/all/0/1">S. Malhotra</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Omont_A/0/1/0/all/0/1">A. Omont</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Scott_D/0/1/0/all/0/1">D. Scott</a> We present an extensive CO emission-line survey of the Planck’s dusty GEMS, a small set of 11 strongly lensed dusty star-forming galaxies at z = 2-4 discovered with Planck and Herschel satellites, using EMIR on the IRAM 30-m telescope. We detected a total of 45 CO rotational lines from Jup=3Read More →

Ultra-high energy cosmic rays from supermassive black holes: particle flux on the Earth and extragalactic diffuse emission. (arXiv:1811.11216v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Uryson_A/0/1/0/all/0/1">A. Uryson</a> Cosmic rays accelerated to ultra-high energies (E>4×10^19 eV) in electric fields in accretion discs around supermassive black holes are discussed. Particle injection spectra are assumed to be harder than those formed in acceleration on shock fronts. It turned out that cosmic rays with injection spectra supposed contribute a little in the particle flux detected with ground-based arrays. But in the extragalactic space particle generate a noticeable flux of the diffuse gamma-ray emission compared with the data obtained with the Fermi LAT instrument (onboardRead More →

174P/Echeclus and its Blue Coma Observed Post-Outburst. (arXiv:1811.11220v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Seccull_T/0/1/0/all/0/1">Tom Seccull</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fraser_W/0/1/0/all/0/1">Wesley C. Fraser</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Puzia_T/0/1/0/all/0/1">Thomas H. Puzia</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fitzsimmons_A/0/1/0/all/0/1">Alan Fitzsimmons</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cupani_G/0/1/0/all/0/1">Guido Cupani</a> It has been suggested that centaurs may lose their red surfaces and become bluer due to the onset of cometary activity, but the way in which cometary outbursts affect the surface composition and albedo of active centaurs is poorly understood. We obtained consistent visual-NIR reflectance spectra of the sporadically active centaur 174P/Echeclus during a period of inactivity in 2014 and six weeks after its outburst in 2016 to see if activity had observably changed the surface properties of theRead More →

A search for radius inflation among active M-dwarfs in Praesepe. (arXiv:1811.11232v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Jackson_R/0/1/0/all/0/1">R.J. Jackson</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Jeffries_R/0/1/0/all/0/1">R.D. Jeffries</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Deliyannis_C/0/1/0/all/0/1">Constantine P. Deliyannis</a> (2), <a href="http://arxiv.org/find/astro-ph/1/au:+Sun_Q/0/1/0/all/0/1">Qinghui Sun</a> (2), <a href="http://arxiv.org/find/astro-ph/1/au:+Douglas_S/0/1/0/all/0/1">Stephanie T. Douglas</a> (3) ((1) Astrophysics Group, Keele University, (2) Department of Astronomy, Indiana University, (3) Harvard-Smithsonian Center for Astrophysics) Rotation periods from Kepler K2 are combined with projected rotation velocities from the WIYN 3.5-m telescope, to determine projected radii for fast-rotating, low-mass ($0.15 leq M/M_{odot} leq 0.6$) members of the Praesepe cluster. A maximum likelihood analysis that accounts for observational uncertainties, binarity and censored data, yields marginal evidence for radius inflation — the averageRead More →

Results of a search for sub-GeV dark matter using 2013 LUX data. (arXiv:1811.11241v1 [astro-ph.CO]) <a href="http://arxiv.org/find/astro-ph/1/au:+Akerib_D/0/1/0/all/0/1">D.S. Akerib</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Alsum_S/0/1/0/all/0/1">S. Alsum</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Araujo_H/0/1/0/all/0/1">H.M. Ara&#xfa;jo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bai_X/0/1/0/all/0/1">X. Bai</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Balajthy_J/0/1/0/all/0/1">J. Balajthy</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Beltrame_P/0/1/0/all/0/1">P. Beltrame</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bernard_E/0/1/0/all/0/1">E.P. Bernard</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bernstein_A/0/1/0/all/0/1">A. Bernstein</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Biesiadzinski_T/0/1/0/all/0/1">T.P. Biesiadzinski</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Boulton_E/0/1/0/all/0/1">E.M. Boulton</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Boxer_B/0/1/0/all/0/1">B. Boxer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bras_P/0/1/0/all/0/1">P. Br&#xe1;s</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Burdin_S/0/1/0/all/0/1">S. Burdin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Byram_D/0/1/0/all/0/1">D. Byram</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Carmona_Benitez_M/0/1/0/all/0/1">M.C. Carmona-Benitez</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chan_C/0/1/0/all/0/1">C. Chan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cutter_J/0/1/0/all/0/1">J.E. Cutter</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Davison_T/0/1/0/all/0/1">T.J.R. Davison</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Druszkiewicz_E/0/1/0/all/0/1">E. Druszkiewicz</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fallon_S/0/1/0/all/0/1">S.R. Fallon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fan_A/0/1/0/all/0/1">A. Fan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fiorucci_S/0/1/0/all/0/1">S. Fiorucci</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gaitskell_R/0/1/0/all/0/1">R.J. Gaitskell</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Genovesi_J/0/1/0/all/0/1">J. Genovesi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ghag_C/0/1/0/all/0/1">C. Ghag</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gilchriese_M/0/1/0/all/0/1">M.G.D. Gilchriese</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gwilliam_C/0/1/0/all/0/1">C. Gwilliam</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hall_C/0/1/0/all/0/1">C.R. Hall</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Haselschwardt_S/0/1/0/all/0/1">S.J. Haselschwardt</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hertel_S/0/1/0/all/0/1">S.A. Hertel</a>, <aRead More →

Simultaneous analysis of SDSS spectra and GALEX photometry with STARLIGHT: Method and early results. (arXiv:1811.11255v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Werle_A/0/1/0/all/0/1">Ariel Werle</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fernandes_R/0/1/0/all/0/1">Roberto Cid Fernandes</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Asari_N/0/1/0/all/0/1">Natalia Vale Asari</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bruzual_G/0/1/0/all/0/1">Gustavo Bruzual</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Charlot_S/0/1/0/all/0/1">St&#xe9;phane Charlot</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Delgado_R/0/1/0/all/0/1">Rosa Gonzalez Delgado</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Herpich_F/0/1/0/all/0/1">Fabio Herpich</a> We combine data from the Sloan Digital Sky Survey and the Galaxy Evolution Explorer to simultaneously analyze optical spectra and ultraviolet photometry of 231643 galaxies with the STARLIGHT spectral synthesis code using state-of-the-art stellar population models. We present a new method to estimate GALEX photometry in the SDSS spectroscopic aperture, which proves quite reliable if applied to large samples. In agreement with previous experiments withRead More →

Multi-frequency variability study of Ton 599 during high activity of 2017. (arXiv:1811.11256v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Prince_R/0/1/0/all/0/1">Raj Prince</a> In this work, I have presented a multi-frequency variability and correlation study of the blazar Ton 599, which was observed first time in flaring state at the end of 2017. Data from textit{Fermi}-LAT, Swift-XRT/UVOT, Steward Observatory, and OVRO (15 GHz) is used, and it is found that the source is more variable in $gamma$-ray and optical/UV than X-ray and radio. Large variations in the degree of polarization (DoP) and position angle (PA) is noticed during the flaring period. Maximum flux during $gamma$-ray flare is found to be 12.63$times$10$^{-7}$ atRead More →

Compaction and Melt Transport in Ammonia-Rich Ice Shells: Implications for the Evolution of Triton. (arXiv:1811.11257v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Hammond_N/0/1/0/all/0/1">Noah P. Hammond</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Parmentier_M/0/1/0/all/0/1">Marc Parmentier</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Barr_A/0/1/0/all/0/1">Amy C. Barr</a> Ammonia, if present in the ice shells of icy satellites, could lower the temperature for the onset of melting to 176 K and create a large temperature range where partial melt is thermally stable. The evolution of regions of ammonia-rich partial melt could strongly influence the geological and thermal evolution of icy bodies. For melt to be extracted from partially molten regions, the surrounding solid matrix must deform and compact. Whether ammonia-rich melts sink to the subsurface oceanRead More →

Radio Forensics Could Unmask Nearby Off-axis Gamma-ray Bursts. (arXiv:1811.11260v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Bartos_I/0/1/0/all/0/1">Imre Bartos</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lee_K/0/1/0/all/0/1">Kyung-hwan Lee</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Corsi_A/0/1/0/all/0/1">Alessandra Corsi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Marka_Z/0/1/0/all/0/1">Zsuzsa Marka</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Marka_S/0/1/0/all/0/1">Szabolcs Marka</a> The multi-messenger observation of gamma-ray burst (GRB),170817A from the nearby binary neutron-star merger GW170817 demonstrated that low-energy $gamma$-ray emission can be observed at relatively large angles from GRB jet axes. If such structured emission is typical, then the currently known sample of short GRBs with no distance measurements may contain multiple nearby off-axis events whose delayed afterglows could have gone undetected. These nearby neutron star mergers may produce telltale radio flares peaking years after the prompt GRB emission that couldRead More →

ALMA, ATCA, and Spitzer Observations of the Luminous Extragalactic Supernova SN 1978K. (arXiv:1811.11267v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Smith_I/0/1/0/all/0/1">I. A. Smith</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ryder_S/0/1/0/all/0/1">S. D. Ryder</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kotak_R/0/1/0/all/0/1">R. Kotak</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kool_E/0/1/0/all/0/1">E. C. Kool</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Randall_S/0/1/0/all/0/1">S. K. Randall</a> Only three extragalactic supernovae have been detected at late times at millimeter wavelengths: SN 1987A, SN 1978K, and SN 1996cr. SN 1978K is a remarkably luminous Type IIn supernova that remains bright at all wavelengths 40 years after its explosion. Here we present Atacama Large Millimeter/submillimeter Array (ALMA) observations taken in 2016 using Bands 3, 4, 6, and 7 that show a steepening in the spectrum. An absorbed single power law modelRead More →

SOFIA – HIRMES: Looking forward to the HIgh-Resolution Mid-infrarEd Spectrometer. (arXiv:1811.11313v1 [astro-ph.IM]) <a href="http://arxiv.org/find/astro-ph/1/au:+Richards_S/0/1/0/all/0/1">Samuel N. Richards</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Moseley_S/0/1/0/all/0/1">Samuel H. Moseley</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Stacey_G/0/1/0/all/0/1">Gordon Stacey</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Greenhouse_M/0/1/0/all/0/1">Matthew Greenhouse</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kutyrev_A/0/1/0/all/0/1">Alexander Kutyrev</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Arendt_R/0/1/0/all/0/1">Richard Arendt</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Atanasoff_H/0/1/0/all/0/1">Hristo Atanasoff</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Banks_S/0/1/0/all/0/1">Stuart Banks</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Brekosky_R/0/1/0/all/0/1">Regis P. Brekosky</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Brown_A/0/1/0/all/0/1">Ari-David Brown</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bulcha_B/0/1/0/all/0/1">Berhanu Bulcha</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cazeau_T/0/1/0/all/0/1">Tony Cazeau</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Choi_M/0/1/0/all/0/1">Michael Choi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Colazo_F/0/1/0/all/0/1">Felipe Colazo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Engler_C/0/1/0/all/0/1">Chuck Engler</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hadjimichael_T/0/1/0/all/0/1">Theodore Hadjimichael</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hays_Wehle_J/0/1/0/all/0/1">James Hays-Wehle</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Henderson_C/0/1/0/all/0/1">Chuck Henderson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hsieh_W/0/1/0/all/0/1">Wen-Ting Hsieh</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Huang_J/0/1/0/all/0/1">Jeffrey Huang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jenstrom_I/0/1/0/all/0/1">Iver Jenstrom</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kellogg_J/0/1/0/all/0/1">Jim Kellogg</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kimball_M/0/1/0/all/0/1">Mark Kimball</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kovacs_A/0/1/0/all/0/1">Attila Kovacs</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Leiter_S/0/1/0/all/0/1">Steve Leiter</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Maher_S/0/1/0/all/0/1">Steve Maher</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+McMurray_R/0/1/0/all/0/1">Robert McMurray</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Melnick_G/0/1/0/all/0/1">Gary J. Melnick</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mentzell_E/0/1/0/all/0/1">Eric Mentzell</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mikula_V/0/1/0/all/0/1">VilemRead More →

Subdwarf B stars as possible surviving companions in Type Ia supernova remnants. (arXiv:1811.11351v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Meng_X/0/1/0/all/0/1">Xiangcun Meng</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Li_J/0/1/0/all/0/1">Jiao Li</a> Although type Ia supernovae (SNe Ia) are so important in many astrophysical fields, a debate on their progenitor model is still endless. Searching the surviving companion in a supernova remnant (SNR) may distinguish different progenitor models, since a companion still exists in the remnant for the single-degenerate (SD) model, but does not for the double degenerate (DD) model. However, some recent surveys do not discover the surviving companions in the remnant of SN 1006 and Kepler’s supernova, which seems to disfavor the SD model. SuchRead More →