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Related papers: Observing the Accretion Stream in Polars

200 papers

Wide-field time-domain photometric sky surveys are now finding hundreds of eclipsing white dwarf plus M dwarf binaries, a population encompassing a wealth of information and potential insight into white dwarf and close binary astrophysics.…

Spherical and axisymmetric accretion onto black holes is discussed. Physical processes in various families of solutions are explained and their characteristics are summarized. Recently discovered solutions of axisymmetric flow provide us…

Astrophysics · Physics 2009-10-31 Myeong-Gu Park , Jeremiah P. Ostriker

We run three-dimensional numerical simulations for the accretion flow around the white dwarf (WD) in the progenitor system of Tycho's supernova (SN). The mass of the WD, mass of the companion star, and the orbital period are set to be…

Solar and Stellar Astrophysics · Physics 2020-12-09 Li Xue , Cheng-Liang Jiao , Yuan Li

We calculated diffusion timescales for Ca, Mg, Fe in hydrogen atmosphere white dwarfs with temperatures between 5000 and 25000 K. With these timescales we determined accretion rates for a sample of 38 DAZ white dwarfs from the recent…

Astrophysics · Physics 2009-11-11 D. Koester , D. Wilken

This paper reports the ULTRACAM discovery of dipolar surface spots in two cool magnetic white dwarfs with Balmer emission lines, while a third system exhibits a single spot, similar to the prototype GD 356. The light curves are modeled with…

Solar and Stellar Astrophysics · Physics 2023-07-26 J. Farihi , J. J. Hermes , S. P. Littlefair , I. D. Howarth , N. Walters , S. G. Parsons

Polars and low-accretion rate polars (LARPs) are strongly magnetic cataclysmic variables. Mediated by the magnetic field of the white dwarf, their spin and binary orbit are (mostly) synchronized. They play an important role in our…

Solar and Stellar Astrophysics · Physics 2025-05-16 Axel D. Schwope

White dwarfs that have accreted planetary bodies are a powerful probe of the bulk composition of exoplanetary material. In this paper, we present a Bayesian model to explain the abundances observed in the atmospheres of 202 DZ white dwarfs…

Earth and Planetary Astrophysics · Physics 2021-03-31 John H. D. Harrison , Amy Bonsor , Mihkel Kama , Andrew M. Buchan , Simon Blouin , Detlev Koester

The polarimetry of the light scattered by planetary surfaces is a powerful tool to provide constraints on their microstructure. To improve the interpretation of polarimetric data from icy surfaces, we have developed the POLarimeter for ICE…

Earth and Planetary Astrophysics · Physics 2018-09-25 Olivier Poch , Romain Cerubini , Antoine Pommerol , Bernhard Jost , Nicolas Thomas

We study the power spectra of the variability of seven intermediate polars containing magnetized asynchronous accreting white dwarfs, XSS J00564+4548,IGR J00234+6141, DO Dra, V1223 Sgr, IGR J15094-6649, IGR J16500-3307 and IGR J17195-4100,…

We present a long-term optical and X-ray photometric study of AN UMa, one of the prototypical polar-type cataclysmic variables, tracing more than 34 years of its accretion history. Observations from both ground-based and space-based…

Solar and Stellar Astrophysics · Physics 2025-07-16 S. Ok , M. Yardimci , B. Kalomeni , A. Schwope

We present an analysis of high-dispersion and high signal-to-noise ratio spectra of the DAZ white dwarf GALEX J1931+0117. The spectra obtained with the VLT-Kueyen/UV-Visual Echelle Spectrograph show several well-resolved Si II spectral…

Solar and Stellar Astrophysics · Physics 2015-05-20 Stephane Vennes , Adela Kawka , Peter Nemeth

We present analytical and numerical solutions which describe a hot, viscous, two-temperature accretion flow onto a neutron star or any other compact star with a surface. We assume Coulomb coupling between the protons and electrons, and…

Astrophysics · Physics 2009-11-06 Mikhail V. Medvedev

Several evolutionary sequences with low--mass secondaries ($M_d $=1.25, 1.5 and 1.7$ M_\odot $) and black hole accretors ($M_{bh} $=5 and 10$ M_\odot$) are calculated. The angular momentum losses due to magnetic braking and gravitational…

Astrophysics · Physics 2009-11-06 Ene Ergma , Marek J. Sarna

We present results of a semi-analytic model (SAM) that includes cold accretion and a porosity-based prescription for star formation. We can recover the puzzling observational results of low $V/\sigma$ seen in various massive disk or…

Astrophysics · Physics 2015-05-13 S. Khochfar , J. Silk

I collect emission line profiles for seven intermediate polars, phase-resolved over the spin cycles. I then present the first systematic application of Doppler tomography to the spin cycles, with the aim of investigating whether spin-cycle…

Astrophysics · Physics 2009-10-31 Coel Hellier

We present new calculations of the attenuation of stellar light from spiral galaxies using geometries for stars and dust which can reproduce the entire spectral energy distribution from the UV to the FIR/submm and can also account for the…

Using Chandra HETG data we present light curves for individual spectral lines of Mg XI and Mg XII for EX Hydrae, an intermediate-polar type cataclysmic variable. The Mg XI light curve, folded on the white dwarf spin period, shows two spikes…

Astrophysics · Physics 2009-11-11 R. Hoogerwerf , N. S. Brickhouse , C. W. Mauche

In order to confirm the anisotropic effect of resonance photons in hot accretion columns on white dwarfs in magnetic cataclysmic variables, proposed by Terada etal (2001), systematic studies with ASCA of 7 polars and 12 intermediate polars…

Astrophysics · Physics 2015-06-24 Yukikatsu Terada , Manabu Ishida , Kazuo Makishima

The availability of a robust and efficient routine for calculating light curves of a finite source magnified due to bending its light by the gravitational field of an intervening binary lens is essential for determining the characteristics…

Astrophysics · Physics 2008-11-26 M. Dominik

Dust in the diffuse interstellar medium remains incompletely understood with regard to the structure, composition, size distribution, and alignment properties of the grains. Joint observations of reddening, starlight polarisation spectra,…

Astrophysics of Galaxies · Physics 2026-05-27 Ralf Siebenmorgen , Stefano Bagnulo , Lapo Fanciullo , Thomas Vannieuwenhuyse , Vincent Guillet