RAS_WEB (Page 4,571)

Tidal disruptions of rotating stars by a supermassive black hole. (arXiv:1901.05644v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Kagaya_K/0/1/0/all/0/1">Kazuki Kagaya</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yoshida_S/0/1/0/all/0/1">Shin&#x27;ichirou Yoshida</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tanikawa_A/0/1/0/all/0/1">Ataru Tanikawa</a> We compare mass infall rates of tidal-disruption debris of a non-rotating and of a rotating star when they come close to a supermassive black hole at the center of a galaxy. Remarkably the mass distribution of debris bound to the black hole as a function of specific energy shows clear difference between rotating and non-rotating stars, even if the stellar rotation is far from the break-up limit. The debris of a star whose initial spin is parallel to the orbital angular momentum has aRead More →

Active Optics in Astonomy – Modeling of freeform deformable substrates – FIREBall and MESSIER. (arXiv:1901.05650v1 [astro-ph.IM]) <a href="http://arxiv.org/find/astro-ph/1/au:+Lemaitre_G/0/1/0/all/0/1">Gerard R. Lemaitre</a> (LAM) Active optics techniques on large telescopes and astronomical instrumentations provide high imaging quality. For ground-based astronomy, the co-addition of adaptive optics again increases angular resolution up to provide diffraction-limited imaging at least in the infrared. Active and adaptive optics marked milestone progress in the detection of exoplanets, super-massive black holes, and large scale structure of galaxies. This paper is dedicated to highly deformable active optics that can generate non-axisymmetric aspheric surfaces-or freeform surfaces-by use of a minimum number of actuators: a single uniform loadRead More →

Dark Matter Self Interactions and its Impact on Large Scale Structures. (arXiv:1901.05658v1 [astro-ph.CO]) <a href="http://arxiv.org/find/astro-ph/1/au:+Chatterjee_C/0/1/0/all/0/1">Chayan Chatterjee</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Majumdar_D/0/1/0/all/0/1">Debasish Majumdar</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chatterjee_S/0/1/0/all/0/1">Suchetana Chatterjee</a> The LambdaCDM model of cosmology, though very successful at large scales, has some discrepancy with observations at the galactic and sub-galactic scales. These include the core-cusp problem, missing satellites problem etc. Spergel and Steingardt (2000) proposed that if dark matter undergoes feeble self interactions with each other, then such problems can be averted. In this thesis, a two-component dark matter model involving two singlet scalar fields capable of self-interactions has been proposed and its impact on large scale structure formation has been studiedRead More →

New models of Jupiter in the context of Juno and Galileo. (arXiv:1901.05697v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Debras_F/0/1/0/all/0/1">Florian Debras</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chabrier_G/0/1/0/all/0/1">Gilles Chabrier</a> Observations of Jupiter’s gravity field by Juno have revealed surprisingly small values for the high order gravitational moments, considering the abundances of heavy elements measured by Galileo 20 years ago. The derivation of recent equations of state for hydrogen and helium, much denser in the Mbar region, worsen the conflict between these two observations. In order to circumvent this puzzle, current Jupiter model studies either ignore the constraint from Galileo or invoke an ad hoc modification of the equations of state. In this paper, we deriveRead More →

A Model-Independent Measurement of the Spatial Curvature using Cosmic Chronometers and the HII Hubble Diagram. (arXiv:1901.05705v1 [astro-ph.CO]) <a href="http://arxiv.org/find/astro-ph/1/au:+Zheng_J/0/1/0/all/0/1">Jing Zheng</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Melia_F/0/1/0/all/0/1">Fulvio Melia</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zhang_T/0/1/0/all/0/1">Tong-Jie Zhang</a> We propose a model-independent way to determine the cosmic curvature using the Hubble parameter $H(z)$ measured with cosmic chronometers and the comoving distance $D(z)$ inferred from HII galaxies. We employ Gaussian processes to smooth the measure of distance and match it to $30$ values of $H(z)$. The curvature parameter $Omega_k$ may be obtained individually for each such pair. The weighted average for the complete sample is $Omega_k=-0.0013pm0.0004$, suggesting a bias towards negative values. The accuracy of the curvature measurementRead More →

The Light-Trap: A novel concept for a large SiPM-based pixel for Very High Energy gamma-ray astronomy and beyond. (arXiv:1901.05736v1 [astro-ph.IM]) <a href="http://arxiv.org/find/astro-ph/1/au:+Guberman_D/0/1/0/all/0/1">D. Guberman</a> (1,4), <a href="http://arxiv.org/find/astro-ph/1/au:+Cortina_J/0/1/0/all/0/1">J. Cortina</a> (1,5), <a href="http://arxiv.org/find/astro-ph/1/au:+Ward_J/0/1/0/all/0/1">J. E. Ward</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Espinera_E/0/1/0/all/0/1">E. Do Souto Espi&#xf1;era</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Hahn_A/0/1/0/all/0/1">A. Hahn</a> (2), <a href="http://arxiv.org/find/astro-ph/1/au:+Mazin_D/0/1/0/all/0/1">D. Mazin</a> (2,3), ((1) Institut de F&#xed;sica d&#x27;Altes Energies (IFAE), The Barcelona Institute of Science and Technology (BIST), Bellaterra (Barcelona), Spain, (2) Max-Planck-Institut f&#xfc;r Physik, M&#xfc;nchen, Germany, (3) also at ICRR, The University of Tokyo, Chiba, Japan, (4) Now at Universita di Pisa, and INFN Pisa, Pisa, Italy, (5) Now at Centro de Investigaciones Energ&#xe9;ticas, Medioambientales y Tecnol&#xf3;gicas (CIEMAT), Madrid, Spain)Read More →

The solar chromosphere at millimetre and ultraviolet wavelengths. I. Radiation temperatures and a detailed comparison. (arXiv:1901.05763v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Jafarzadeh_S/0/1/0/all/0/1">Shahin Jafarzadeh</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wedemeyer_S/0/1/0/all/0/1">Sven Wedemeyer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Szydlarski_M/0/1/0/all/0/1">Mikolaj Szydlarski</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pontieu_B/0/1/0/all/0/1">Bart De Pontieu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rezaei_R/0/1/0/all/0/1">Reza Rezaei</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Carlsson_M/0/1/0/all/0/1">Mats Carlsson</a> Solar observations with the Atacama Large Millimeter/submillimeter Array (ALMA) provide us with direct measurements of the brightness temperature in the solar chromosphere. We study the temperature distributions obtained with ALMA Band 6 (in four sub-bands at 1.21, 1.22, 1.29, and 1.3 mm) for various areas at, and in the vicinity of, a sunspot, comprising quasi-quiet and active regions with different amounts of underlying magnetic fields. We compare these temperaturesRead More →

High velocity string of knots in the outburst of the Planetary Nebula Hb4. (arXiv:1901.05767v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Derlopa_S/0/1/0/all/0/1">Sophia Derlopa</a> (1,2), <a href="http://arxiv.org/find/astro-ph/1/au:+Akras_S/0/1/0/all/0/1">Stavros Akras</a> (3), <a href="http://arxiv.org/find/astro-ph/1/au:+Boumis_P/0/1/0/all/0/1">Panos Boumis</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Steffen_W/0/1/0/all/0/1">Wolfgang Steffen</a> (4), ((1) Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, National Observatory of Athens, Greece, (2) Department of Physics, University of Athens, Greece, (3) Observatorio Nacional/MCTIC, Rio de Janeiro, Brazil, (4) Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, Ensenada, Mexico) The bipolar collimated outflows of the Hb4 Planetary Nebula (PN) exhibit an evident decrease in their expansion velocity with respect to the distance from the central star. So far, similar velocity law hasRead More →

Strong lensing reveals jets in a sub-microJy radio quiet quasar. (arXiv:1901.05791v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Hartley_P/0/1/0/all/0/1">P. Hartley</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jackson_N/0/1/0/all/0/1">N. Jackson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sluse_D/0/1/0/all/0/1">D. Sluse</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Stacey_H/0/1/0/all/0/1">H. R. Stacey</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Arias_H/0/1/0/all/0/1">H. Vives Arias</a> We present e-MERLIN and EVN observations which reveal unambiguous jet activity within radio quiet quasar HS~0810+2554. With an intrinsic flux density of 880~nJy, this is the faintest radio source ever imaged. The findings present new evidence against the idea that radio loud and radio quiet quasars are powered by different underlying radio emission mechanisms, showing instead that the same AGN mechanism can operate as the dominant source of radio emission even in the very lowest radioRead More →

A comparison between short GRB afterglows and KN170817: shedding light on kilonovae properties. (arXiv:1901.05792v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Rossi_A/0/1/0/all/0/1">A. Rossi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Stratta_G/0/1/0/all/0/1">G. Stratta</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Maiorano_E/0/1/0/all/0/1">E. Maiorano</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Spighi_D/0/1/0/all/0/1">D. Spighi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Masetti_N/0/1/0/all/0/1">N. Masetti</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Palazzi_E/0/1/0/all/0/1">E. Palazzi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gardini_A/0/1/0/all/0/1">A. Gardini</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Melandri_A/0/1/0/all/0/1">A. Melandri</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nicastro_L/0/1/0/all/0/1">L. Nicastro</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pian_E/0/1/0/all/0/1">E. Pian</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Branchesi_M/0/1/0/all/0/1">M. Branchesi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dadina_M/0/1/0/all/0/1">M. Dadina</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Testa_V/0/1/0/all/0/1">V. Testa</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Brocato_S/0/1/0/all/0/1">S. Brocato</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:+Ciolfi_R/0/1/0/all/0/1">R. Ciolfi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Covino_S/0/1/0/all/0/1">S. Covino</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+DElia_V/0/1/0/all/0/1">V. D&#x27;Elia</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Grado_A/0/1/0/all/0/1">A. Grado</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Izzo_L/0/1/0/all/0/1">L. Izzo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Perego_A/0/1/0/all/0/1">A. Perego</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Piranomonte_S/0/1/0/all/0/1">S. Piranomonte</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Salvaterra_R/0/1/0/all/0/1">R. Salvaterra</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Selsing_J/0/1/0/all/0/1">J. Selsing</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:+Yang_S/0/1/0/all/0/1">S. Yang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vergani_D/0/1/0/all/0/1">D. Vergani</a> Multi-messenger astronomy started with the discovery of kilonova AT2017gfo,Read More →

Rise and fall of molecular clouds across the M33 disk. (arXiv:1901.05804v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Corbelli_E/0/1/0/all/0/1">Edvige Corbelli</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Braine_J/0/1/0/all/0/1">Jonathan Braine</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Giovanardi_C/0/1/0/all/0/1">Carlo Giovanardi</a> We carried out deep searches for CO line emission in the outer disk of M33, at R>7 kpc, and examined the dynamical conditions that can explain variations in the mass distribution of the molecular cloud throughout the disk of M33. We used the IRAM-30~m telescope to search for CO lines in the outer disk toward 12 faint mid-infrared (MIR) selected sources and in an area of the southern outer disk hosting MA1, a bright HII region. We detect narrow CO lines at the locationRead More →

Dark Matter phenomenology : from simplified WIMP models to refined alternative solutions. (arXiv:1901.05822v1 [hep-ph]) <a href="http://arxiv.org/find/hep-ph/1/au:+Pierre_M/0/1/0/all/0/1">Mathias Pierre</a> One of the most puzzling problems of modern physics is the identification of the nature a non-relativistic matter component present in the universe, contributing to more than 25$%$ of the total energy budget, known as Dark Matter. Weakly Interacting Massive Particles (WIMPs) are among the best motivated dark matter candidates. However, in light of non conclusive detection signals and strong constraints from collider, direct and indirect detection experiments, this thesis presents constraints on several realizations of the WIMP paradigm in the context of simplified dark matter models. MoreRead More →

Concerning pressure and entropy of shock-accelerated heliosheath electrons. (arXiv:1901.05848v1 [physics.space-ph]) <a href="http://arxiv.org/find/physics/1/au:+Fahr_H/0/1/0/all/0/1">Hans J. Fahr</a>, <a href="http://arxiv.org/find/physics/1/au:+Dutta_Roy_R/0/1/0/all/0/1">Robindro Dutta-Roy</a> We study the behaviour of shocked wind-electrons leaving wind-driving stars after undergoing the outer wind termination shock. As an example, we describe the evolution of the keV-energetic electron distribution function downstream of the heliospheric termination shock. We start from a kinetic transport equation in the bulk frame of the heliosheath plasma flow taking into account shock-induced electron injection, convective changes, cooling processes, and whistler wave-induced energy diffusion. From this equation we proceed to an associated pressure moment of the electron distribution function arriving at a corresponding pressure transportRead More →

Spitzer transit follow-up of planet candidates from the K2 mission. (arXiv:1901.05855v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Livingston_J/0/1/0/all/0/1">John H. Livingston</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Crossfield_I/0/1/0/all/0/1">Ian J. M. Crossfield</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Werner_M/0/1/0/all/0/1">Michael W. Werner</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gorjian_V/0/1/0/all/0/1">Varoujan Gorjian</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Petigura_E/0/1/0/all/0/1">Erik A. Petigura</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ciardi_D/0/1/0/all/0/1">David R. Ciardi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dressing_C/0/1/0/all/0/1">Courtney D. Dressing</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fulton_B/0/1/0/all/0/1">Benjamin J. Fulton</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hirano_T/0/1/0/all/0/1">Teruyuki Hirano</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Schlieder_J/0/1/0/all/0/1">Joshua E. Schlieder</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sinukoff_E/0/1/0/all/0/1">Evan Sinukoff</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kosiarek_M/0/1/0/all/0/1">Molly Kosiarek</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Akeson_R/0/1/0/all/0/1">Rachel Akeson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Beichman_C/0/1/0/all/0/1">Charles A. Beichman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Benneke_B/0/1/0/all/0/1">Bj&#xf6;rn Benneke</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Christiansen_J/0/1/0/all/0/1">Jessie L. Christiansen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hansen_B/0/1/0/all/0/1">Bradley M. S. Hansen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Howard_A/0/1/0/all/0/1">Andrew W. Howard</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Isaacson_H/0/1/0/all/0/1">Howard Isaacson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Knutson_H/0/1/0/all/0/1">Heather A. Knutson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Krick_J/0/1/0/all/0/1">Jessica Krick</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Martinez_A/0/1/0/all/0/1">Arturo O. Martinez</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sato_B/0/1/0/all/0/1">Bun&#x27;ei Sato</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tamura_M/0/1/0/all/0/1">Motohide Tamura</a> We present precision 4.5 $mu$mRead More →

Optimizing the accuracy and efficiency of optical turbulence profiling using adaptive optics telemetry for extremely large telescopes. (arXiv:1901.05860v1 [astro-ph.IM]) <a href="http://arxiv.org/find/astro-ph/1/au:+Laidlaw_D/0/1/0/all/0/1">Douglas J Laidlaw</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Osborn_J/0/1/0/all/0/1">James Osborn</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Morris_T/0/1/0/all/0/1">Timothy J Morris</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Basden_A/0/1/0/all/0/1">Alastair G Basden</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Beltramo_Martin_O/0/1/0/all/0/1">Olivier Beltramo-Martin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Butterley_T/0/1/0/all/0/1">Timothy Butterley</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gendron_E/0/1/0/all/0/1">Eric Gendron</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Reeves_A/0/1/0/all/0/1">Andrew P Reeves</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rousset_G/0/1/0/all/0/1">G&#xe9;rard Rousset</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Townson_M/0/1/0/all/0/1">Matthew J Townson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wilson_R/0/1/0/all/0/1">Richard W Wilson</a> Advanced adaptive optics (AO) instruments on ground-based telescopes require accurate knowledge of the atmospheric turbulence strength as a function of altitude. This information assists point spread function reconstruction, AO temporal control techniques and is required by wide-field AO systems to optimize the reconstruction of an observed wavefront.Read More →

Chemical composition of post-AGB star candidates. (arXiv:1901.05866v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Molina_R/0/1/0/all/0/1">R. E. Molina</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pereira_C/0/1/0/all/0/1">C. B. Pereira</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ferro_A/0/1/0/all/0/1">A. Arellano Ferro</a> We present a high resolution detailed abundance analysis for a sample of six post-AGB candidate stars, five of them had not been studied spectroscopically in the optical region. All the analyzed objects are IRAS sources identified as possible post-AGB on the two-colours IRAS diagram. We find three objects with clear signs of evolved stars; IRAS 05338-3051 shows abundances similar to the RV Tauri V453 Oph; the lower-luminosity stars IRAS 18025 – 3906 is O-rich without s-process enrichment and IRAS 18386 – 1253 shows a moderateRead More →

Observations of solar small-scale magnetic flux-sheet emergence. (arXiv:1901.05870v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Fischer_C/0/1/0/all/0/1">C.E. Fischer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Borrero_J/0/1/0/all/0/1">J.M. Borrero</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gonzalez_N/0/1/0/all/0/1">N. Bello Gonz&#xe1;lez</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kaithakkal_A/0/1/0/all/0/1">A.J. Kaithakkal</a> Aims. Moreno-Insertis et al. (2018) recently discovered two types of flux emergence in their numerical simulations: magnetic loops and magnetic sheet emergence. Whereas magnetic loop emergence has been documented well in the last years, by utilising high-resolution full Stokes data from ground-based telescopes as well as satellites, magnetic sheet emergence is still an understudied process. We report here on the first clear observational evidence of a magnetic sheet emergence and characterise its development. Methods. Full Stokes spectra from the Hinode spectropolarimeter were invertedRead More →

Cross-helically forced and decaying hydromagnetic turbulence. (arXiv:1901.05875v1 [physics.flu-dyn]) <a href="http://arxiv.org/find/physics/1/au:+Brandenburg_A/0/1/0/all/0/1">Axel Brandenburg</a> (Nordita), <a href="http://arxiv.org/find/physics/1/au:+Oughton_S/0/1/0/all/0/1">Sean Oughton</a> (University of Waikato) We study the evolution of kinetic and magnetic energy spectra in magnetohydrodynamic flows in the presence of strong cross helicity. For forced turbulence, we find weak inverse transfer of kinetic energy toward the smallest wavenumber. This is plausibly explained by the finiteness of scale separation between the injection wavenumber and the smallest wavenumber of the domain, which here is a factor of 15. In the decaying case, there is a slight increase at the smallest wavenumber, which is probably explained by the dominance of kinetic energy overRead More →

On the Ubiquity and Stellar Luminosity Dependence of Exocometary CO Gas: Detection around M Dwarf TWA 7. (arXiv:1901.05004v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Matra_L/0/1/0/all/0/1">Luca Matr&#xe0;</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Oberg_K/0/1/0/all/0/1">Karin I. &#xd6;berg</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wilner_D/0/1/0/all/0/1">David J. Wilner</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Olofsson_J/0/1/0/all/0/1">Johan Olofsson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bayo_A/0/1/0/all/0/1">Amelia Bayo</a> Millimeter observations of CO gas in planetesimal belts show a high detection rate around A stars, but few detections for later type stars. We present the first CO detection in a planetesimal belt around an M star, TWA 7. The optically thin CO (J=3-2) emission is co-located with previously identified dust emission from the belt, and the emission velocity structure is consistent with Keplerian rotation around the central star.Read More →

Phenotypic redshifts with self-organizing maps: A novel method to characterize redshift distributions of source galaxies for weak lensing. (arXiv:1901.05005v1 [astro-ph.CO]) <a href="http://arxiv.org/find/astro-ph/1/au:+Buchs_R/0/1/0/all/0/1">R. Buchs</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Davis_C/0/1/0/all/0/1">C. Davis</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gruen_D/0/1/0/all/0/1">D. Gruen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+DeRose_J/0/1/0/all/0/1">J. DeRose</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Alarcon_A/0/1/0/all/0/1">A. Alarcon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bernstein_G/0/1/0/all/0/1">G. M. Bernstein</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sanchez_C/0/1/0/all/0/1">C. S&#xe1;nchez</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Myles_J/0/1/0/all/0/1">J. Myles</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Roodman_A/0/1/0/all/0/1">A. Roodman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Allen_S/0/1/0/all/0/1">S. Allen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Amon_A/0/1/0/all/0/1">A. Amon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Choi_A/0/1/0/all/0/1">A. Choi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Masters_D/0/1/0/all/0/1">D. C. Masters</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Miquel_R/0/1/0/all/0/1">R. Miquel</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Troxel_M/0/1/0/all/0/1">M. A. Troxel</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wechsler_R/0/1/0/all/0/1">R. H. Wechsler</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Abbott_T/0/1/0/all/0/1">T. M. C. Abbott</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Annis_J/0/1/0/all/0/1">J. Annis</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Avila_S/0/1/0/all/0/1">S. Avila</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bechtol_K/0/1/0/all/0/1">K. Bechtol</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bridle_S/0/1/0/all/0/1">S. L. Bridle</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Brooks_D/0/1/0/all/0/1">D. Brooks</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Buckley_Geer_E/0/1/0/all/0/1">E. Buckley-Geer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Burke_D/0/1/0/all/0/1">D. L. Burke</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rosell_A/0/1/0/all/0/1">A. Carnero Rosell</a>, <aRead More →