RAS_WEB (Page 4,068)

A dust and gas cavity in the disc around CQ Tau revealed by ALMA. (arXiv:1905.00909v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Gabellini_M/0/1/0/all/0/1">M. Giulia Ubeira Gabellini</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Miotello_A/0/1/0/all/0/1">Anna Miotello</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Facchini_S/0/1/0/all/0/1">Stefano Facchini</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ragusa_E/0/1/0/all/0/1">Enrico Ragusa</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lodato_G/0/1/0/all/0/1">Giuseppe Lodato</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Testi_L/0/1/0/all/0/1">Leonardo Testi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Benisty_M/0/1/0/all/0/1">Myriam Benisty</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bruderer_S/0/1/0/all/0/1">Simon Bruderer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kurtovic_N/0/1/0/all/0/1">Nicol&#xe0;s T. Kurtovic</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Andrews_S/0/1/0/all/0/1">Sean Andrews</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Carpenter_J/0/1/0/all/0/1">John Carpenter</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Corder_S/0/1/0/all/0/1">Stuartt A. Corder</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dipierro_G/0/1/0/all/0/1">Giovanni Dipierro</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ercolano_B/0/1/0/all/0/1">Barbara Ercolano</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fedele_D/0/1/0/all/0/1">Davide Fedele</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Guidi_G/0/1/0/all/0/1">Greta Guidi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Henning_T/0/1/0/all/0/1">Thomas Henning</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Isella_A/0/1/0/all/0/1">Andrea Isella</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kwon_W/0/1/0/all/0/1">Woojin Kwon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Linz_H/0/1/0/all/0/1">Hendrik Linz</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+McClure_M/0/1/0/all/0/1">Melissa McClure</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Perez_L/0/1/0/all/0/1">Laura Perez</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ricci_L/0/1/0/all/0/1">Luca Ricci</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rosotti_G/0/1/0/all/0/1">Giovanni Rosotti</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tazzari_M/0/1/0/all/0/1">Marco Tazzari</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wilner_D/0/1/0/all/0/1">David Wilner</a> The combination of high resolution and sensitivityRead More →

STROOPWAFEL: Simulating rare outcomes from astrophysical populations, with application to gravitational-wave sources. (arXiv:1905.00910v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Broekgaarden_F/0/1/0/all/0/1">Floor S. Broekgaarden</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Justham_S/0/1/0/all/0/1">Stephen Justham</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mink_S/0/1/0/all/0/1">Selma E. de Mink</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gair_J/0/1/0/all/0/1">Jonathan Gair</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mandel_I/0/1/0/all/0/1">Ilya Mandel</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Stevenson_S/0/1/0/all/0/1">Simon Stevenson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Barrett_J/0/1/0/all/0/1">Jim W. Barrett</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vigna_Gomez_A/0/1/0/all/0/1">Alejandro Vigna-G&#xf3;mez</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Neijssel_C/0/1/0/all/0/1">Coenraad J. Neijssel</a> Gravitational-wave observations of double compact object (DCO) mergers are providing new insights into the physics of massive stars and the evolution of binary systems. Making the most of expected near-future observations for understanding stellar physics will rely on comparisons with binary population synthesis models. However, the vast majority of simulated binaries never produce DCOs, which makes calculating such populationsRead More →

Photometric redshift galaxies as tracers of the filamentary network. (arXiv:1905.00912v1 [astro-ph.CO]) <a href="http://arxiv.org/find/astro-ph/1/au:+Kruuse_M/0/1/0/all/0/1">Maarja Kruuse</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tempel_E/0/1/0/all/0/1">Elmo Tempel</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kipper_R/0/1/0/all/0/1">Rain Kipper</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Stoica_R/0/1/0/all/0/1">Radu S. Stoica</a> Galaxy filaments are the dominant feature in the overall structure of the cosmic web. The study of the filamentary web is an important aspect in understanding galaxy evolution and the evolution of matter in the Universe. A map of the filamentary structure is an adequate probe of the web. We propose that photometric redshift galaxies are significantly positively associated with the filamentary structure detected from the spatial distribution of spectroscopic redshift galaxies. The catalogues of spectroscopic and photometric galaxies are seenRead More →

Assembling a RELIC at Redshift 1: Spectroscopic Observations of Galaxies in the RELICS Cluster SPT-CLJ0615-5746. (arXiv:1905.00914v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Connor_T/0/1/0/all/0/1">Thomas Connor</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kelson_D/0/1/0/all/0/1">Daniel D. Kelson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Blanc_G/0/1/0/all/0/1">Guillermo A. Blanc</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Boutsia_K/0/1/0/all/0/1">Konstantina Boutsia</a> We present a catalog of spectroscopic redshifts for SPT-CLJ0615$-$5746, the most distant cluster in the Reionization Lensing Cluster Survey (RELICS). Using Nod & Shuffle multi-slit observations with LDSS-3 on Magellan, we identify ${sim}50$ cluster members and derive a cluster redshift of $z_c = 0.972$, with a velocity dispersion of $sigma = 1235 pm 170 textrm{km} textrm{s}^{-1}$. We calculate a cluster mass using a $sigma_{200}-M_{200}$ scaling relation of $M_{200} = (9.4 pm 3.6) times 10^{14}Read More →

7.1 keV sterile neutrino dark matter constraints from a deep Chandra X-ray observation of the Galactic bulge Limiting Window. (arXiv:1905.00916v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Hofmann_F/0/1/0/all/0/1">F. Hofmann</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wegg_C/0/1/0/all/0/1">C. Wegg</a> Recently an unidentified emission line at 3.55 keV has been detected in X-ray spectra of clusters of galaxies. The line has been discussed as a possible decay signature of 7.1 keV sterile neutrinos, which have been proposed as a dark matter (DM) candidate. We aim to further constrain the line strength and its implied mixing angle under the assumption that all DM is made of sterile neutrinos. The X-ray observations of the Limiting Window (LW) towards the GalacticRead More →

Do Androids Dream of Magnetic Fields? Using Neural Networks to Interpret the Turbulent Interstellar Medium. (arXiv:1905.00918v1 [astro-ph.IM]) <a href="http://arxiv.org/find/astro-ph/1/au:+Peek_J/0/1/0/all/0/1">J. E. G. Peek</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Burkhart_B/0/1/0/all/0/1">Blakesley Burkhart</a> The interstellar medium (ISM) of galaxies is composed of a turbulent magnetized plasma. In order to quantitatively measure relevant turbulent parameters of the ISM, a wide variety of statistical techniques and metrics have been developed that are often tested using numerical simulations and analytic formalism. These metrics are typically based on the Fourier power spectrum, which does not capture the Fourier phase information that carries the morphological characteristics of images. In this work we use density slices of magnetohydrodyanmic turbulenceRead More →

The Probability Distribution of Density Fluctuations in Supersonic Turbulence. (arXiv:1905.00923v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Pan_L/0/1/0/all/0/1">Liubin Pan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Padoan_P/0/1/0/all/0/1">Paolo Padoan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nordlund_%7B/0/1/0/all/0/1">&#xc5;ke Nordlund</a> We study density fluctuations in supersonic turbulence using both theoretical methods and numerical simulations. A theoretical formulation is developed for the probability distribution function (PDF) of the density at steady state, connecting it to the conditional statistics of the velocity divergence. Two sets of numerical simulations are carried out, using either a Riemann solver to evolve the Euler equations or a finite-difference method to evolve the Navier-Stokes (N-S) equations. After confirming the validity of our theoretical formulation with the N-S simulations, we examine the effectsRead More →

Outgassing As Trigger of 1I/`Oumuamua’s Nongravitational Acceleration: Could This Hypothesis Work at All?. (arXiv:1905.00935v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Sekanina_Z/0/1/0/all/0/1">Zdenek Sekanina</a> The question of what triggered the nongravitational acceleration of 1I/`Oumuamua continues to attract researchers’ attention. The absence of any signs of activity notwithstanding, the prevailing notion is that the acceleration of the stellar, cigar-like object was prompted by outgassing. However, the Spitzer Space Telescope’s failure to detect `Oumuamua not only ruled out the CO_2 and/or CO driven activity (Trilling et al. 2018), but made the cigar shape incompatible with the optical observations. Choice of water ice as the source of outgassing is shown to be flawed asRead More →

Optical and X-ray Correlations During the 2015 Outburst of the Black Hole V404 Cyg. (arXiv:1905.00949v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Hynes_R/0/1/0/all/0/1">R. I. Hynes</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Robinson_E/0/1/0/all/0/1">E. L. Robinson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Terndrup_D/0/1/0/all/0/1">D. M. Terndrup</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gandhi_P/0/1/0/all/0/1">P. Gandhi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Froning_C/0/1/0/all/0/1">C. S. Froning</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Starrfield_R/0/1/0/all/0/1">R. M. Wagner S. Starrfield</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> We present a serendipitous multiwavelength campaign of optical photometry simultaneous with Integral X-ray monitoring of the 2015 outburst of the black hole V404 Cyg. Large amplitude optical variability is generally correlated with X-rays, with lags of order a minute or less compatible with binary light travel timescales or jet ejections. Rapid optical flaring on time-scales ofRead More →

The Effective Surface Area of Amorphous Solid Water Measured by the Infrared Absorption of Carbon Monoxide. (arXiv:1905.00969v1 [astro-ph.IM]) <a href="http://arxiv.org/find/astro-ph/1/au:+He_J/0/1/0/all/0/1">Jiao He</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Clements_A/0/1/0/all/0/1">Aspen R. Clements</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Emtiaz_S/0/1/0/all/0/1">SM Emtiaz</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Toriello_F/0/1/0/all/0/1">Francis Toriello</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Garrod_R/0/1/0/all/0/1">Robin T. Garrod</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vidali_G/0/1/0/all/0/1">Gianfranco Vidali</a> The need to characterize ices coating dust grains in dense interstellar clouds arises from the importance of ice morphology in facilitating the diffusion and storage of radicals and reaction products in ices, a well-known place for the formation of complex molecules. Yet, there is considerable uncertainty about the structure of ISM ices, their ability to store volatiles and under what conditions. We measured the infrared absorption spectraRead More →

Precise Measures of Orbital Period, Before and After Nova Eruption for QZ Aurigae. (arXiv:1905.00974v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Schaefer_B/0/1/0/all/0/1">Bradley E. Schaefer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Boyd_D/0/1/0/all/0/1">David Boyd</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Clayton_G/0/1/0/all/0/1">Geoffrey C. Clayton</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Frank_J/0/1/0/all/0/1">Juhan Frank</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Johnson_C/0/1/0/all/0/1">Christopher Johnson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kemp_J/0/1/0/all/0/1">Jonathan Kemp</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pagnotta_A/0/1/0/all/0/1">Ashley Pagnotta</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Patterson_J/0/1/0/all/0/1">Joseph O. Patterson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Marco_M/0/1/0/all/0/1">Miguel Rodriguez Marco</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Xiao_L/0/1/0/all/0/1">Limin Xiao</a> For the ordinary classical nova QZ Aurigae (which erupted in 1964), we report 1317 magnitudes from 1912–2016, including four eclipses detected on archival photographic plates from long before the eruption. We have accurate and robust measures of the orbital period both pre-eruption and post-eruption, and we find that the orbital period decreased, with a fractional changeRead More →

GBTrans: A commensal search for radio pulses with theGreen Bank twenty metre telescope. (arXiv:1905.00980v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Golpayegani_G/0/1/0/all/0/1">Golnoosh Golpayegani</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lorimer_D/0/1/0/all/0/1">Duncan R. Lorimer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ellingson_S/0/1/0/all/0/1">Steven W. Ellingson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Agarwal_D/0/1/0/all/0/1">Devansh Agarwal</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Young_O/0/1/0/all/0/1">Olivia Young</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ghigo_F/0/1/0/all/0/1">Frank Ghigo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Prestage_R/0/1/0/all/0/1">Richard Prestage</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rajwade_K/0/1/0/all/0/1">Kaustubh Rajwade</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+McLaughlin_M/0/1/0/all/0/1">Maura A. McLaughlin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mingyar_M/0/1/0/all/0/1">Michael Mingyar</a> We describe GBTrans, a real-time search system designed to find fast radio bursts (FRBs) using the 20-m radio telescope at the Green Bank Observatory. The telescope has been part of the Skynet educational program since 2015. We give details of the observing system and report on the non-detection of FRBs from a total observing time of 503Read More →

A Global View of QCD Axion Stars. (arXiv:1905.00981v1 [hep-ph]) <a href="http://arxiv.org/find/hep-ph/1/au:+Eby_J/0/1/0/all/0/1">Joshua Eby</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Leembruggen_M/0/1/0/all/0/1">Madelyn Leembruggen</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Street_L/0/1/0/all/0/1">Lauren Street</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Suranyi_P/0/1/0/all/0/1">Peter Suranyi</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Wijewardhana_L/0/1/0/all/0/1">L.C.R. Wijewardhana</a> Taking a comprehensive view, including a full range of boundary conditions, we reexamine QCD axion star solutions based on the relativistic Klein-Gordon equation (using the Ruffini-Bonazzola approach) and its non-relativistic limit, the Gross-Pit”aevskii equation. A single free parameter, conveniently chosen as the central value of the wave function with range $0 < Z(0)< infty$, or alternatively the chemical potential with range $-mRead More →

Analysis of Small-scale Magnetic Flux Ropes Covering the Whole Ulysses Mission. (arXiv:1905.00986v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Chen_Y/0/1/0/all/0/1">Yu Chen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hu_Q/0/1/0/all/0/1">Qiang Hu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Roux_J/0/1/0/all/0/1">Jakobus le Roux</a> Small-scale magnetic flux ropes, in the solar wind, have been studied for decades via the approach of both simulation and observation. Statistical analysis utilizing various in-situ spacecraft measurements is the main observational approach. In this study, we extend the automated detection of small-scale flux ropes based on the Grad-Shafranov reconstruction to the complete dataset of emph{Ulysses} spacecraft in-situ measurements. We first discuss the temporal variation of the bulk properties of 22,719 flux ropes found through our approach, namely, the average magnetic fieldRead More →

Nuclear kinematics in nearby AGN. I. An ALMA perspective on the Morphology and Kinematics of the molecular CO(2-1) emission. (arXiv:1905.00994v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Ramakrishnan_V/0/1/0/all/0/1">V. Ramakrishnan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nagar_N/0/1/0/all/0/1">N. M. Nagar</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Finlez_C/0/1/0/all/0/1">C. Finlez</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Storchi_Bergmann_T/0/1/0/all/0/1">T. Storchi-Bergmann</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Slater_R/0/1/0/all/0/1">R. Slater</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Schnorr_Muller_A/0/1/0/all/0/1">A. Schnorr-M&#xfc;ller</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Riffel_R/0/1/0/all/0/1">R. A. Riffel</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mundell_C/0/1/0/all/0/1">C. G. Mundell</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Robinson_A/0/1/0/all/0/1">A. Robinson</a> We present the molecular gas morphology and kinematics of seven nearby Seyfert galaxies obtained from our 230~GHz ALMA observations. The CO J=2-1 kinematics within the inner $sim30$” ($lesssim9$~kpc) reveals rotation patterns that have been explored using the Bertola rotation model and a modified version of the Kinemetry package. The latter algorithm reveals various deviationsRead More →

Effective repulsion in dense quark matter from non-perturbative gluon exchange. (arXiv:1905.01005v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Song_Y/0/1/0/all/0/1">Yifan Song</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Baym_G/0/1/0/all/0/1">Gordon Baym</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hatsuda_T/0/1/0/all/0/1">Tetsuo Hatsuda</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kojo_T/0/1/0/all/0/1">Toru Kojo</a> A moderately strong vector repulsion between quarks in dense quark matter is needed to explain how a quark core can support neutron stars heavier than two solar masses. We study this repulsion, parametrized by a four-fermion interaction with coupling g_V, in terms of non-perturbative gluon exchange in QCD in the Landau gauge. Matching the energy of quark matter, g_V n_q^2 (where n_q is the number density of quarks) with the quark exchange energy calculated in QCD with a gluon propagator parametrizedRead More →

Accounting for Multiplicity in Calculating Eta Earth. (arXiv:1905.01032v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Zink_J/0/1/0/all/0/1">Jon K. Zink</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hansen_B/0/1/0/all/0/1">Bradley M. S. Hansen</a> Using the updated exoplanet population parameters of our previous study, which includes the planetary radius updates from Gaia DR2 and an inferred multiplicity distribution, we provide a revised $eta_{oplus}$ calculation. This is achieved by sampling planets from our derived population model and determining which planets meet our criterion for habitability. To ensure robust results, we provide probabilities calculated over a range of upper radius limits. Our most optimistic criterion for habitability provides an $eta_{oplus}$ value of $0.34pm 0.02 frac{rm planets}{rm star}$. We also consider the effects ofRead More →

Time dependent spectral modeling of Markarian 421 during a violent outburst in 2010. (arXiv:1905.01043v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Banerjee_B/0/1/0/all/0/1">B. Banerjee</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Joshi_M/0/1/0/all/0/1">M. Joshi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Majumdar_P/0/1/0/all/0/1">P. Majumdar</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Williamson_K/0/1/0/all/0/1">K. E. Williamson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jorstad_S/0/1/0/all/0/1">S. G. Jorstad</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Marscher_A/0/1/0/all/0/1">A. P. Marscher</a> We present the results of extensive modeling of the spectral energy distributions (SEDs) of the closest blazar (z=0.031) Markarian 421 (Mrk 421) during a giant outburst in February 2010. The source underwent rapid flux variations in both X-rays and very high energy (VHE) gamma-rays as it evolved from a low-flux state on 2010 February 13-15 to a high-flux state on 2010 February 17. During this period, the source exhibitedRead More →

Dust particle size and optical depth on Mars retrieved by the MSL Navigation Cameras. (arXiv:1905.01073v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Chen_Chen_H/0/1/0/all/0/1">H. Chen-Chen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Perez_Hoyos_S/0/1/0/all/0/1">S. Perez-Hoyos</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sanchez_Lavega_A/0/1/0/all/0/1">A. Sanchez-Lavega</a> In this paper we show that Sun-viewing images obtained by the Mars Science Laboratory (MSL) Navigation Cameras (Navcam) can be used for retrieving the dust optical depth and constrain the aerosol physical properties at Gale Crater by evaluating the sky brightness as a function of the scattering angle. We have used 65 Sun-pointing images covering a period of almost three Martian years, from MSL mission sol 21 to sol 1646 (MY 31 to 33). Radiometric calibration and geometric reduction wereRead More →

Characterisation of Martian dust aerosol phase function from sky radiance measurements by MSL engineering cameras. (arXiv:1905.01074v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Chen_Chen_H/0/1/0/all/0/1">H. Chen-Chen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Perez_Hoyos_S/0/1/0/all/0/1">S. Perez-Hoyos</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sanchez_Lavega_A/0/1/0/all/0/1">A. Sanchez-Lavega</a> Dust is the main driver of Mars’ atmospheric variability. The determination of Martian dust aerosol properties is of high relevance for radiative modelling and calculating its weather forcing. In particular, the light scattering behaviour at intermediate and large scattering angles can provide valuable information regarding the airborne dust particle shape. The angular distribution of sky brightness observed by the Mars Science Laboratory engineering cameras (Navcam and Hazcam) is used here to characterise the atmospheric dust single scattering phase functionRead More →