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Related papers: A Numerical Model for Accretion in Intermediate Po…

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(Abridged) We report results of three dimensional MHD simulations of global accretion disks threaded with weak vertical magnetic fields. We perform the simulations in the spherical coordinates with different temperature profiles and…

Earth and Planetary Astrophysics · Physics 2015-06-17 Takeru K. Suzuki , Shu-ichiro Inutsuka

We consider the accretion process in a disk with magnetic fields that are dragged in from the interstellar medium by gravitational collapse. Two diffusive processes are at work in the system: (1) "viscous" torques exerted by turbulent and…

The observations and simulations have revealed that large-scale magnetic field and outflows can exist in the inner regions of an advection-dominated accretion disc where the resistive diffusion may also be important. In the present paper,…

High Energy Astrophysical Phenomena · Physics 2020-06-17 S. M. Ghoreyshi

Large scale magnetic field threading an accretion disk is a key ingredient in the jet formation model. The most attractive scenario for the origin of such a large scale field is the advection of the field by the gas in the accretion disk…

High Energy Astrophysical Phenomena · Physics 2015-06-12 Xinwu Cao , H. C. Spruit

We present our results of Monte-Carlo simulations of polarized Compton X-rays from magnetic cataclysmic variables, with realistic density, temperature and velocity structures in the accretion flow. Our study has shown that the X-ray linear…

High Energy Astrophysical Phenomena · Physics 2016-06-01 Kinwah Wu , Aimee McNamara , Zdenka Kuncic

We study mass ejection from accretion disks formed in the merger of a white dwarf with a neutron star or black hole. These disks are mostly radiatively-inefficient and support nuclear fusion reactions, with ensuing outflows and…

High Energy Astrophysical Phenomena · Physics 2019-07-10 Rodrigo Fernández , Ben Margalit , Brian D. Metzger

I review recent activity in the field of intermediate polars, concentrating on: the mode of accretion (disc-fed, disc-overflow or discless); accretion curtains (the transition region and the accretion footprint); X-ray pulse profiles…

Astrophysics · Physics 2007-05-23 Coel Hellier

Recent calculations of accretion-induced collapse of an oxygen-neon-magnesium white dwarf into a neutron star [Piro & Thompson 2014] allow for a potentially detectable transient electromagnetic signal. Motivated by these results, I present…

Solar and Stellar Astrophysics · Physics 2015-12-03 Damian Kwiatkowski

Around 10% of white dwarfs exhibit global magnetic structures with fields ranging from 1 kG to hundreds of MG. Recently, the first radiation magnetohydrodynamics simulations of the atmosphere of white dwarfs showed that convection should be…

Recent observations of a large number of DA and DB white dwarfs show evidence of debris disks, which are the remnants of old planetary systems. The infrared excess detected with \emph{Spitzer} and the lines of heavy elements observed in…

Solar and Stellar Astrophysics · Physics 2015-06-17 M. Deal , S. Deheuvels , G. Vauclair , S. Vauclair , F. C. Wachlin

RXTE observed 20 eclipse egresses of the intermediate polar XY Ari in order to study the size and structure of the X-ray emitting accretion regions. The spin-phase averaged egress lasts 26 s, implying a white dwarf radius of 4.3-7.0 10^8…

Astrophysics · Physics 2015-06-24 Coel Hellier

We present an analysis of mock X-ray spectra and light curves of magnetic cataclysmic variables using an upgraded version of the 3D CYCLOPS code. This 3D representation of the accretion flow allows us to properly model total and partial…

Recent numerical cosmological radiation-magnetohydrodynamic-thermochemical-star formation simulations have resolved the formation of quasar accretion disks with Eddington or super-Eddington accretion rates onto supermassive black holes…

The accretion-induced collapse (AIC) of a rotating white dwarf (WD) offers a potential site of millisecond pulsars/magnetars, gamma-ray bursts, and r-process nucleosynthesis. We present three-dimensional general-relativistic…

High Energy Astrophysical Phenomena · Physics 2025-09-25 Luciano Combi , Daniel M. Siegel , Brian D. Metzger

Context. White dwarfs (WDs) in cataclysmic variables (CVs) are important experimental laboratories where the electron degeneracy is taking place on a macroscopic scale. Magnetic CVs increase in number especially in the hard X-ray band (>10…

High Energy Astrophysical Phenomena · Physics 2015-05-19 Takayuki Yuasa , Kazuhiro Nakazawa , Kazuo Makishima , Kei Saitou , Manabu Ishida , Ken Ebisawa , Hideyuki Mori , Shin'ya Yamada

Rotating magnetized white dwarfs are studied within the framework of general relativity using Hartle's formalism. Matter inside magnetized white dwarfs is described by an equation of state of particles under the action of a constant…

High Energy Astrophysical Phenomena · Physics 2019-02-18 Diana Alvear Terrero , Daryel Manreza Paret , Aurora Perez Martinez

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 use three dimensional magnetohydrodynamic simulations to study the structure of the boundary layer between an accretion disc and a non-rotating, unmagnetized star. Under the assumption that cooling is efficient, we obtain a narrow but…

Astrophysics · Physics 2009-11-07 Philip J. Armitage

An accretion scenario in which the material captured by a black hole from its environment is assumed to be magnetized (\beta ~ 1) is discussed. We show that the accretion picture in this case is strongly affected by the magnetic field of…

High Energy Astrophysical Phenomena · Physics 2012-11-20 N. R. Ikhsanov , L. A. Pustil'nik , N. G. Beskrovnaya

Pulsation modes have recently been observed in a handful of white dwarf (WD) primaries of cataclysmic variables, allowing an interesting new probe into the structure of accreting WD's. We briefly discuss the seismology of these objects, how…

Astrophysics · Physics 2007-05-23 Phil Arras , Dean Townsley , Lars Bildsten