Monitoring of X-Ray Sources in the Optical Spectral Region

We review current results and perspectives of the photometric monitoring of the optical counterparts of X-ray sources of various kinds (binary X-ray sources (cataclysmic variables and low-mass X-ray binaries, supersoft X-ray sources, microquasars), gamma-ray bursts). We discuss the problems of the monitoring of the individual kinds of objects in the optical and X-ray passbands. We show the importance of multifilter monitoring to obtain a deeper understanding of the physical processes and to resolve between the individual emission mechanisms. We also show that there are brief, unique, and little understood phenomena which are very promising targets for the optical monitoring, for example, flares in intermediate polars.

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Multiwavelength Modeling the SED of Strongly Interacting Binaries

Proceedings of the International Astronomical Union ◽

10.1017/s1743921311026913 ◽

2011 ◽

Vol 7 (S282) ◽

pp. 65-66

Author(s):

Augustin Skopal

Keyword(s):

Physical Parameters ◽

X Rays ◽

Physical Processes ◽

Short Contribution ◽

Composite Spectrum ◽

X Ray ◽

Strongly Interacting ◽

Low Mass ◽

X Ray Binaries

AbstractThe spectrum of strongly interacting binaries, as for example, high and low mass X-ray binaries, symbiotic (X-ray) binaries and/or classical and recurrent novae, consists of more components of radiation contributing from hard X-rays to radio wavelengths. To understand the basic physical processes responsible for the observed spectrum we have to disentangle the composite spectrum into its individual components, i.e. to determine their physical parameters. In this short contribution I demonstrate the method of modeling the multiwavelength SED on the example of the extragalactic super-soft X-ray source RX J0059.1-7505 (LIN 358).

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X-ray sources in Galactic globular clusters and old open clusters

Proceedings of the International Astronomical Union ◽

10.1017/s1743921319007981 ◽

2019 ◽

Vol 14 (S351) ◽

pp. 367-376

Author(s):

Maureen van den Berg

Keyword(s):

Globular Clusters ◽

Cataclysmic Variables ◽

Star Clusters ◽

Open Clusters ◽

Encounter Rate ◽

X Ray ◽

Low Mass ◽

New Perspective ◽

X Ray Binaries ◽

Cluster Age

AbstractThe features and make up of the population of X-ray sources in Galactic star clusters reflect the properties of the underlying stellar environment. Cluster age, mass, stellar encounter rate, binary frequency, metallicity, and maybe other properties as well, determine to what extent we can expect a contribution to the cluster X-ray emission from low-mass X-ray binaries, millisecond pulsars, cataclysmic variables, and magnetically active binaries. Sensitive X-ray observations withXMM-Newton and certainlyChandra have yielded new insights into the nature of individual sources and the effects of dynamical encounters. They have also provided a new perspective on the collective X-ray properties of clusters, in which the X-ray emissivities of globular clusters and old open clusters can be compared to each other and to those of other environments. I will review our current understanding of cluster X-ray sources, focusing on star clusters older than about 1 Gyr, illustrated with recent results.

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Common Envelope Evolution and Formation of Cataclysmic Variables and Low-Mass X-ray Binaries

X-Ray Binaries and Recycled Pulsars ◽

10.1007/978-94-011-2704-2_26 ◽

1992 ◽

pp. 269-280 ◽

Cited By ~ 26

Author(s):

R. F. Webbink

Keyword(s):

Cataclysmic Variables ◽

X Ray ◽

Common Envelope ◽

Low Mass ◽

X Ray Binaries

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The Intermediate Polars

International Astronomical Union Colloquium ◽

10.1017/s0252921100090291 ◽

1983 ◽

Vol 72 ◽

pp. 155-172

Author(s):

Brian Warner

Keyword(s):

Magnetic Fields ◽

White Dwarf ◽

Variable Star ◽

Theoretical Models ◽

Cataclysmic Variable ◽

General Role ◽

X Ray ◽

Low Mass ◽

Intermediate Polars ◽

X Ray Binaries

Until 1976, cataclysmic variable star research proceeded with few requirements for the inclusion of magnetic fields in theoretical models. Although models for low-mass X-ray binaries stressed the importance of magnetic fields (Lamb et at. 1973) and there was an increasing number of known magnetic single white dwarfs (Angel 1977), and a magnetised white dwarf had been one of the models proposed to explain the rapid oscillations in DQ Her (Herbst et al. 1974, Katz 1975), there was no anticipation of the more general role that magnetic fields now seem destined to play. The two major reviews of the time (Robinson 1976, Warner 1976) scarcely considered the presence of magnetic fields.

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A Fuse Survey of Disk-Accreting Cataclysmic Variables

International Astronomical Union Colloquium ◽

10.1017/s0252921100152960 ◽

2004 ◽

Vol 194 ◽

pp. 251-251

Author(s):

C. S. Froning ◽

K. S. Long ◽

P. Szkody ◽

B. T. Gänsicke

Keyword(s):

Cataclysmic Variables ◽

Dwarf Novae ◽

X Ray ◽

Intermediate Polars ◽

Far Ultraviolet ◽

X Ray Binaries ◽

Initial Results

We present initial results of a survey of the FUV spectra of disk-accreting cataclysmic variables obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE).FUSE covers the 905 - 1188 Å range at spectral resolutions ≃0.1 Å. To date, FUSE has observed more than 65 cataclysmic variables (CVs). Publicly-available data include observations of 11 dwarf novae (DN), 15 non-magnetic novalikes (NLs), 7 intermediate polars and DQ Her stars, at least 15 polars, and 4 super-soft X-ray binaries.

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Theory of Accretion Disk Coronae

International Astronomical Union Colloquium ◽

10.1017/s025292110001232x ◽

1990 ◽

Vol 115 ◽

pp. 187-196

Author(s):

T. R. Kallman

Keyword(s):

Active Galactic Nuclei ◽

Accretion Disk ◽

Cataclysmic Variables ◽

Galactic Nuclei ◽

X Ray ◽

Spectral Signatures ◽

Low Mass ◽

X Ray Absorption ◽

X Ray Binaries ◽

Theoretical Issues

AbstractAccretion disk coronae are likely to be the dominant site for X-ray absorption and reprocessed emission in low mass X-ray binaries, and may be present in other classes of compact X-ray sources such as active galactic nuclei and cataclysmic variables. In spite of this fact, and in spite of the observational evidence for their existence, there remain many uncertainties about the structure of accretion disk coronae. This paper will discuss the coronal structure and dynamics, their X-ray spectral signatures including coupling to the variability behavior of compact X-ray sources, and the major unsolved theoretical issues surrounding them.

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Observational Evidence for the Origin of X-ray Sources in Globular Clusters

Proceedings of the International Astronomical Union ◽

10.1017/s1743921308015822 ◽

2007 ◽

Vol 3 (S246) ◽

pp. 301-310 ◽

Cited By ~ 7

Author(s):

Frank Verbunt ◽

Dave Pooley ◽

Cees Bassa

Keyword(s):

Statistical Method ◽

Globular Clusters ◽

Cataclysmic Variables ◽

Observational Evidence ◽

X Ray ◽

Cluster Mass ◽

Low Mass ◽

Optical Identifications ◽

X Ray Binaries

AbstractLow-mass X-ray binaries, recycled pulsars, cataclysmic variables and magnetically active binaries are observed as X-ray sources in globular clusters. We discuss the classification of these systems, and find that some presumed active binaries are brighter than expected. We discuss a new statistical method to determine from observations how the formation of X-ray sources depends on the number of stellar encounters and/or on the cluster mass. We show that cluster mass is not a proxy for the encounter number, and that optical identifications are essential in proving the presence of primordial binaries among the low-luminosity X-ray sources.

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Modeling He-Rich Disks in AM CVn Binaries

International Astronomical Union Colloquium ◽

10.1017/s025292110015273x ◽

2004 ◽

Vol 194 ◽

pp. 228-228

Author(s):

T. Nagel ◽

S. Dreizler ◽

T. Rauch ◽

K. Werner

Keyword(s):

Accretion Disk ◽

Time Scales ◽

Accretion Disks ◽

White Dwarf ◽

Cataclysmic Variables ◽

X Ray ◽

Synthetic Spectra ◽

Pure Helium ◽

Low Mass ◽

X Ray Binaries

We have developed a new code for the calculation of synthetic spectra and vertical structures of accretion disks in cataclysmic variables and compact X-ray binaries. Here we present results for the CV system AM CVn.AM CVn stars are a special type of cataclysmic variables, also called helium cataclysmics. They are systems of interacting binary white dwarfs, consisting of a degenerate C-O white dwarf primary and a low mass semi-degenerate secondary. The secondary loses mass, almost, pure helium, to the primary, forming an accretion disk. They have all in common a helium-rich composition, analoguous to the hydrogen-rich cataclysmic variables. They show photometric variabilities on time scales of ~ 1000s, the prototype of the class, AM CVn, e.g. exhibits a variability of ~ 18 min (Nelemans et al. 2001).

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