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Related papers: Locating the flickering source in polars

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We present an analysis of 30 archival ASCA and RXTE X-ray observations of 16 intermediate polars to investigate the nature of their orbital modulation. We show that X-ray orbital modulation is widespread amongst these systems, but not…

Astrophysics · Physics 2009-11-10 T. L. Parker , A. J. Norton , K. Mukai

We review our understanding of the prototype ``Propeller'' system AE Aqr and we examine its flaring behaviour in detail. The flares are thought to arise from collisions between high density regions in the material expelled from the system…

Astrophysics · Physics 2007-05-23 K. J. Pearson , Keith Horne , Warren Skidmore

Symbiotic binaries exhibit a wide range of photometric variability spanning different timescales attributed to orbital motion, intrinsic variability of individual components, or the interaction between the two stars. In the range from…

Solar and Stellar Astrophysics · Physics 2023-12-27 J. Merc , P. G. Beck , S. Mathur , R. A. García

Accretion disks around compact objects are expected to enter an unstable phase at high luminosity. One instability may occur when the radiation pressure generated by accretion modifies the disk viscosity, resulting in the cyclic depletion…

We discuss the constraints that recent observations place on circular polarization in AGN. In many sources the circular polarization is variable on short timescales, indicating that it originates in compact regions of the sources. The best…

Astrophysics · Physics 2007-05-23 J. -P. Macquart

An initially retrograde accretion flow is transformed into a prograde configuration before plunging into the black hole, as a result of the frame-dragging effect induced by the black hole's rotation. The polarized image of a black hole…

General Relativity and Quantum Cosmology · Physics 2025-08-22 Xinyu Wang , Songbai Chen , Minyong Guo , Bin Chen

The new generations of multiwavelength radioheliographs with high spatial resolution will employ microwave imaging spectropolarimetry to recover flare topology and plasma parameters in the flare sources and along the wave propagation paths.…

Solar and Stellar Astrophysics · Physics 2017-09-27 A. Altyntsev , N. Meshalkina , I. Myshyakov , V. Pal`shin , G. Fleishman

Polar-ring galaxies are systems with two nearly orthogonal rotational axes, and are therefore clearly the result of galaxy-galaxy interactions. The host galaxies of polar rings are typically gas-poor early-type systems. The rings…

Astrophysics · Physics 2007-05-23 Paul B. Eskridge , Richard W. Pogge

We analyze spectroscopic and photometric observations of the eclipsing polar BS Tri. The polar's light curve shape variations can be interpreted by changing contributions of the accretion stream to the integral radiation of the system.…

High Energy Astrophysical Phenomena · Physics 2022-12-26 A. I. Kolbin , N. V. Borisov , N. A. Serebriakova , V. V. Shimansky , N. A. Katysheva , M. M. Gabdeev , S. Yu. Shugarov

We report on our survey for rapid (time scale of minutes) photometric variability in symbiotic binaries. These binaries are becoming an increasingly important place to study accretion onto white dwarfs since they are candidate Type Ia…

Astrophysics · Physics 2009-11-06 J. L. Sokoloski , Lars Bildsten , Wynn C. G. Ho

We demonstrate that generically an accretion disk around a compact object could have a new type of instability in that the accretion flow need not be symmetric with respect to the equatorial plane even when matter is supplied symmetrically…

Astrophysics · Physics 2015-06-24 D. Molteni , K. Acharya , Oleg Kuznetsov , D. Bisikalo , Sandip K. Chakrabarti

Polar magnetism is present when ions occupy sites that are not centres of inversion symmetry. Fortunately, such magnetization contributes to neutron scattering that is the bedrock of magnetic structure determinations. Experiments in which…

Strongly Correlated Electrons · Physics 2022-08-31 S. W. Lovesey

We study 12 Seyfert 1 galaxies with a high level of optical polarization. Optical light emerging from the innermost regions is predominantly scattered in a polar region above the central engine directly in our line of sight. These sources…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-27 Tobias Beuchert , Jörn Wilms , Matthias Kadler , Anna Lia Longinotti , Matteo Guainazzi , Giovanni Miniutti , Ignacio de la Calle

We present an extension of the King et al. (2004) model for the flickering of black hole accretion discs by taking proper account for the thermal properties of the disc. First we develop a one-dimensional, vertically averaged, one-zone…

Astrophysics · Physics 2008-11-26 M. Mayer , J. E. Pringle

White dwarfs that have accreted rocky planetary bodies provide unique insights regarding the bulk composition of exoplanetary material. The analysis presented here uses observed white dwarf atmospheric abundances to constrain both where in…

Earth and Planetary Astrophysics · Physics 2018-08-06 John H. D. Harrison , Amy Bonsor , Nikku Madhusudhan

The degree of linear polarization has recently been found to show wide random variations over the solar disk. These variations are presumably at least partly due to fluctuations in the flux density of turbulent photospheric magnetic fields…

Astrophysics · Physics 2007-05-23 K. Petrovay

A growing number of debris discs have been detected around metal-polluted white dwarfs. They are thought to be originated from tidally disrupted exoplanetary bodies and responsible for metal accretion onto host WDs. To explain (1) the…

Earth and Planetary Astrophysics · Physics 2022-12-14 Ayaka Okuya , Shigeru Ida , Ryuki Hyodo , Satoshi Okuzumi

Accretion onto black holes often proceeds via an accretion disc or a temporary disc-like pattern. Variability features, observed in the light curves of such objects, and theoretical models of accretion flows suggest that accretion discs are…

High Energy Astrophysical Phenomena · Physics 2016-06-01 V. Karas

Cataclysmic Variables (CVs) are close binary systems where mass is transferred from a red dwarf star to a white dwarf star via an accretion disk. The flickering is observed as stochastic variations in the emitted radiation both in the…

Astrophysics · Physics 2009-11-11 Fabiola Mariana A. Ribeiro , Marcos P. Diaz

Spiral galaxies comprise three major structural components; thin discs, thick discs, and central bulges. Relative dominance of these components is known to correlate with the total mass of the galaxy, and produces a remarkable morphological…

Astrophysics of Galaxies · Physics 2019-05-23 Masafumi Noguchi