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Related papers: The Patchy Accretion Disc in HT Cassiopeiae

200 papers

We report the discovery of a subtle infrared excess associated with the young white dwarf EC\,05365--4749 at 3.35 and 4.6\,$\mu$m. Follow-up spectroscopic observations are consistent with a hydrogen atmosphere white dwarf of effective…

Solar and Stellar Astrophysics · Physics 2016-11-08 E. Dennihy , John H. Debes , B. H. Dunlap , P. Dufour , Johanna K. Teske , J. C. Clemens

The disk atmosphere is one of the fundamental elements of theoretical models of a protoplanetary disk. However, the direct observation of the warm gas (>> 100 K) at large radius of a disk (>> 10 AU) is challenging, because the line emission…

Astrophysics of Galaxies · Physics 2015-06-03 M. Goto , G. van der Plas , M. van den Ancker , C. P. Dullemond , A. Carmona , Th. Henning , G. Meeus , H. Linz , B. Stecklum

Gaseous and dust debris disks around white dwarfs (WDs) are formed from tidally disrupted planetary bodies. This offers an opportunity to determine the composition of exoplanetary material by measuring element abundances in the accreting…

Solar and Stellar Astrophysics · Physics 2016-09-21 S. Hartmann , T. Nagel , T. Rauch , K. Werner

Recent radiation-thermochemical-magnetohydrodynamic simulations resolved formation of quasar accretion disks from cosmological scales down to ~300 gravitational radii $R_{g}$, arguing they were 'hyper-magnetized' (plasma $\beta\ll1$…

To address the discrepancy where disk sizes exceed those predicted by standard models, we explore two extensions to disk size estimates within the UV/optical wavelength range: disk winds and color correction. We provide detailed,…

Astrophysics of Galaxies · Physics 2024-11-15 James Hung-Hsu Chan , Joshua Fagin , Henry Best , Matthew J. O'Dowd

We present theoretical continuum emission spectra (SED's), isophotal maps and line profiles for several models of photoevaporating disks at different orientations with respect to the observer. The hydrodynamic evolution of these models has…

Astrophysics · Physics 2007-05-23 Olaf Kessel , Harold W. Yorke , Sabine Richling

We present three-dimensional Smoothed Particle Hydrodynamics (SPH) simulations investigating the dependence of the accretion rate on the disc thickness around an equal-mass, circular black hole binary system. We find that for thick/hot…

High Energy Astrophysical Phenomena · Physics 2016-05-25 Enrico Ragusa , Giuseppe Lodato , Daniel J. Price

We present the results of reflection calculations that treat the relevant physics with a minimum of assumptions. The temperature and ionization structure of the top five Thomson depths of an illuminated disc are calculated while also…

Astrophysics · Physics 2009-09-17 D. R. Ballantyne , R. R. Ross , A. C. Fabian

Continuum observations at 350um are presented of seven nearby elliptical galaxies, for which CO-gas disks have recently been resolved with interferometry mapping. These SHARCII mapping results provide the first clearly resolved…

The recent ALMA observations of the disc surrounding HL Tau reveal a very complex dust spatial distribution. We present a radiative transfer model accounting for the observed gaps and bright rings as well as radial changes of the emissivity…

We present a thermal emission spectrum of the bloated hot Jupiter HAT-P-32Ab from a single eclipse observation made in spatial scan mode with the Wide Field Camera 3 (WFC3) aboard the Hubble Space Telescope (HST). The spectrum covers the…

We present spectroscopic observations of the quiescent black hole binary A0620-00 with the the 6.5-m Magellan Clay telescope at Las Campanas Observatory. We measure absorption-line radial velocities of the secondary and make the most…

Astrophysics · Physics 2009-11-13 J. Neilsen , D. Steeghs , S. D. Vrtilek

High--resolution 2D--MHD numerical simulations have been carried out to investigate the effects of continuing infall of clumpy gas in extended HI galactic disks. Given a certain accretion rate, the response of the disk depends on its…

Astrophysics · Physics 2009-11-13 A. Santillan , F. J. Sanchez-Salcedo , J. Franco

We investigate the structure of accretion disks around massive protostar applying steady state models of thin disks. The thin disk equations are solved with proper opacities for dust and gas taking into account the huge temperature…

Solar and Stellar Astrophysics · Physics 2009-08-17 B. Vaidya , C. Fendt , H. Beuther

We report the analysis of time-series of infrared $JHK_s$ photometry of the dwarf nova V2051 Oph in quiescence with eclipse mapping techniques to investigate structures and the spectrum of its accretion disc. The light curves after removal…

Solar and Stellar Astrophysics · Physics 2020-01-08 Raymundo Baptista , Eduardo Wojcikiewicz

We study the spectral properties of a very general class of accretion disks which can be decomposed into three distinct components apart from a shock at $r=r_s$: (1) An optically thick Keplerian disk on the equatorial plane ($r>r_s$), (2) A…

Astrophysics · Physics 2009-10-28 Sandip K. Chakrabarti , Lev G. Titarchuk

Geometrically thick disks may form after tidal disruption events, and rapid accretion may lead to short flares followed by long-term, lower-level emission. Using a novel accretion disk code which relies primarily on global conservation laws…

Astrophysics · Physics 2007-05-23 Andrew Ulmer

Ground-based high-resolution spectra provide a powerful tool for characterising exoplanet atmospheres. However, they are greatly hampered by the dominating telluric and stellar lines, which need to be removed prior to any analysis. Such…

Earth and Planetary Astrophysics · Physics 2024-08-27 Doriann Blain , Alejandro Sánchez-López , Paul Mollière

To better understand the physical properties of accretion disks in high-mass star formation, we present a study of a 12 high-mass accretion disk candidates observed at high spatial resolution with the Australia Telescope Compact Array…

Solar and Stellar Astrophysics · Physics 2014-11-20 H. Beuther , A. J. Walsh , S. N. Longmore

We obtained Herschel PACS and SPIRE images of the thermal emission of the debris disk around the A5V star {\beta} Pic. The disk is well resolved in the PACS filters at 70, 100, and 160 {\mu}m. The surface brightness profiles between 70 and…