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Related papers: The Patchy Accretion Disc in HT Cassiopeiae

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We present results of a study of the soft X-ray excess in the black hole candidate Cygnus X-1 made with the {\it Rosat PSPC}, using observations taken during persistent emission at orbital phases close to 0.5. The soft excess can be well…

Astrophysics · Physics 2007-05-23 M. Balucinska-Church , T. Belloni , M. J. Church , G. Hasinger

Accretion disks around supermassive black holes are widely believed to be the dominant source of the optical-ultraviolet continuum in many classes of active galactic nuclei (AGN). We study here the relationship between the continuum colors…

Astrophysics · Physics 2011-02-11 E. W. Bonning , L. Cheng , G. A. Shields , S. Salviander , K. Gebhardt

Many analyses have concluded that the accretion disc sizes measured from the microlensing variability of quasars are larger than the expectations from the standard thin disc theory by a factor of $\sim4$. We propose a simply model by…

High Energy Astrophysical Phenomena · Physics 2018-12-05 Ya-Ping Li , Feng Yuan , Xinyu Dai

Two independent investigations of the atmosphere of the hot Jupiter HAT-P-12b by two different groups resulted in discrepant solutions. Using broad-band photometry from the ground, one study found a flat and featureless transmission…

Earth and Planetary Astrophysics · Physics 2022-01-21 X. Alexoudi , M. Mallonn , C. von Essen , J. D. Turner , E. Keles , J. Southworth , L. Mancini , S. Ciceri , T. Granzer , C. Denker , E. Dineva , K. G. Strassmeier

We present a comprehensive analysis of the HL Tau dust disk by modeling its intensity profiles across six wavelengths (0.45 to 7.9 mm) with a resolution of 0.05 arcsec ($\sim7$ au). Using a Markov Chain Monte Carlo (MCMC) approach, we…

We present derived stellar and disc parameters for a sample of Taurus brown dwarfs both with and without evidence of an associated disc. These parameters have been derived using an online fitting tool (http://bd-server.astro.ex.ac.uk/),…

Solar and Stellar Astrophysics · Physics 2015-06-04 N. J. Mayne , Tim J. Harries , John Rowe , David M. Acreman

Elliptical accretion disk models for tidal disruption events (TDEs) have been recently proposed and independently developed by two groups. Although these two models are characterized by a similar geometry, their physical properties differ…

High Energy Astrophysical Phenomena · Physics 2021-03-03 Fukun Liu , Chunyang Cao , Marek A. Abramowicz , Maciek Wielgus , Rong Cao , Zhiqin Zhou

We present an analysis of Hubble Space Telescope (HST) and XMM-Newton data of the tidal disruption event (TDE) candidate and quasi-periodic eruption (QPE) source GSN 069. Using ultraviolet (UV) and optical images at HST resolution, we show…

High Energy Astrophysical Phenomena · Physics 2025-04-30 M. Guolo , A. Mummery , T. Wevers , M. Nicholl , S. Gezari , A. Ingram , D. R. Pasham

Using three-dimensional general relativistic radiation magnetohydrodynamics simulations of accretion flows around stellar mass black holes, we report that the relatively cold disk ($\gtrsim 10^{7}$K) is truncated near the black hole. Hot…

Astrophysics of Galaxies · Physics 2016-07-27 Hiroyuki R. Takahashi , Ken Ohsuga , Tomohisa Kawashima , Yuichiro Sekiguchi

The Cosmic Hot Interstellar Plasma Spectrometer (CHIPS) was designed to study diffuse emission from hot gas in the local interstellar cavity in the wavelength range 90 - 265 A. Between launch in January 2003 and early 2004, the instrument…

Astrophysics · Physics 2009-11-10 M. Hurwitz , T. P. Sasseen , M. M. Sirk

A new mechanism to form a magnetic pressure supported, high temperature corona above the photosphere of an accretion disk is explored using three dimensional radiation magneto-hydrodynamic (MHD) simulations. The thermal properties of the…

High Energy Astrophysical Phenomena · Physics 2015-06-18 Yan-Fei Jiang , James M. Stone , Shane W. Davis

We report on a new class of solutions of black hole accretion disks that we have found through three-dimensional, global, radiative magnetohydrodynamic simulations in general relativity. It combines features of the canonical thin, slim and…

Disc spectra from highly luminous black hole binaries are observed to be rather simple, despite theoretical predictions to the contrary. We collate the disc-dominated spectra from multiple observations of 10 separate sources, and show that…

Astrophysics · Physics 2009-11-10 Marek Gierlinski , Chris Done

Based on optical and infrared survey data spanning $\approx 20$ years of observations, the long-term variability of the polar V379 Vir with a brown dwarf secondary has been studied. By modeling the spectral energy distribution, we constrain…

Solar and Stellar Astrophysics · Physics 2025-06-24 M. V. Suslikov , A. I. Kolbin , N. V. Borisov

We present a detailed analysis for a subset of the high resolution (~35 mas, or 5 au) ALMA observations from the Disk Substructures at High Angular Resolution Project (DSHARP) to search for faint 1.3 mm continuum emission associated with…

We continue our study of the spectral energy distributions (SEDs) of 11 AGN at 1.5 < z < 2.2, with optical-NIR spectra, X-ray data and mid-IR photometry. In a previous paper we presented the observations and models; in this paper we explore…

High Energy Astrophysical Phenomena · Physics 2016-12-14 James S. Collinson , Martin J. Ward , Hermine Landt , Chris Done , Martin Elvis , Jonathan C. McDowell

We report the electronic structure of CuTe with a high charge density wave (CDW) transition temperature Tc = 335 K by angle-resolved photoemission spectroscopy (ARPES). An anisotropic charge density wave gap with a maximum value of 190 meV…

We present Herschel Space Observatory PACS spectra of T Tauri stars, in which we detect amorphous and crystalline water ice features. Using irradiated accretion disk models, we determine the disk structure and ice abundance in each of the…

Earth and Planetary Astrophysics · Physics 2015-06-23 M. K. McClure , C. Espaillat , N. Calvet , E. Bergin , P. D'Alessio , D. M. Watson , P. Manoj , B. Sargent , L. I. Cleeves

Our previous theoretical study of the impact of an accreting envelope on the thermal state of an underlying white dwarf (WD) has yielded equilibrium core temperatures, classical nova ignition masses and thermal luminosities for WDs…

Astrophysics · Physics 2009-11-10 Dean M. Townsley , Lars Bildsten