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Related papers: Magnetic CVs in Globular Clusters

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We analyze a ~70 ksec Chandra ACIS-I exposure of the globular cluster Omega Centauri (NGC 5139). The ~17 amin x 17 amin field of view fully encompasses three core radii and almost twice the half-mass radius. We detect 180 sources to a…

High Energy Astrophysical Phenomena · Physics 2011-02-11 Daryl Haggard , Adrienne M. Cool , Melvyn B. Davies

Context. The origin, evolution, and ultimate fate of magnetic cataclysmic variables are poorly understood. It is largely the nature of the magnetic fields in these systems that leads to this poor understanding. Fundamental properties, such…

Astrophysics of Galaxies · Physics 2009-11-13 O. W. Butters , S. Katajainen , A. J. Norton , H. J. Lehto , V. Piirola

Five fields located close to the center of the globular cluster NGC 104=47 Tuc were surveyed in a search for variable stars. We present V-band light curves for 42 variables. This sample includes 13 RR Lyr stars -- 12 of them belong to the…

Astrophysics · Physics 2016-08-30 J. Kaluzny , M. Kubiak , M. Szymanski , A. Udalski , W. Krzeminski , M. Mateo , K. Stanek

We present volume-limited samples of cataclysmic variables (CVs) and AM CVn binaries jointly selected from SRG/eROSITA eRASS1 and \textit{Gaia} DR3 using an X-ray + optical color-color diagram (the ``X-ray Main Sequence"). This tool…

Cataclysmic Variables (CVs) are a distinct class of X-ray binaries transferring mass from a donor star to a compact star accretor, a white dwarf. They constitute a laboratory for accretion physics, mechanisms and disk theory together with…

High Energy Astrophysical Phenomena · Physics 2011-12-19 S. Balman

We present a sample of cataclysmic variables (CVs) identified among the X-ray sources from the 400 square degree X-ray survey based on ROSAT pointing data (400d). The procedure of the CV selection among the X-ray sources using additional…

We present VI-band photometry for stars in the metal-rich globular cluster NGC 6496. Our time-series data were cadenced to search for long period variables (LPVs) over a span of nearly two years, and our variability search yielded the…

Observations with BeppoSAX, RXTE and Chandra suggest that many of the bright X-ray sources in globular clusters have ultrashort binary periods. This is remarkable as such systems are not easily formed. With accurate optical astrometry of…

Astrophysics · Physics 2009-11-10 Frank Verbunt

We have obtained deep far- (FUV) and near-ultraviolet (NUV) images of the inner region of the dense globular cluster M15 with the Advanced Camera for Surveys on board the Hubble Space Telescope. The FUV-NUV colour-magnitude diagram shows a…

Astrophysics · Physics 2010-01-28 A. Dieball , C. Knigge , D. R. Zurek , M. M. Shara , K. S. Long , P. A. Charles , D. Hannikainen

We report twelve variables not previously detected in the globular cluster M5 (NGC 5904); one SX Phe and eleven semi-regular variables (SR). Their identifications, equatorial coordinates, ephemerides, and light curves are given.…

Solar and Stellar Astrophysics · Physics 2015-04-16 A. Arellano Ferro , D. M. Bramich , S. Giridhar , A. Luna , S. Muneer

The magnetic cataclysmic variables (MCVs) present a wealth of observational diagnostics for studying accretion flows interacting with a magnetosphere. Spin-period pulsations from the rotation of the white dwarf are seen in optical light, in…

Solar and Stellar Astrophysics · Physics 2015-06-18 Coel Hellier

We report the results of a deep search for faint Chandra X-ray sources, radio sources, and optical counterparts in the nearby, core-collapsed globular cluster, NGC 6752. We combined new and archival Chandra imaging to detect 51 X-ray…

Magnetic cataclysmic variables (CVs) contain a white dwarf with magnetic field strong enough to control the accretion flow from a late type secondary. In this paper, we discover a magnetic CV (CXOGSG J215544.4+380116) from the $Chandra$…

Solar and Stellar Astrophysics · Physics 2017-02-01 Song Wang , Yu Bai , Chuan-peng Zhang , Ji-feng Liu

Magnetic CVs are luminous Galactic X-ray sources but have been difficult to find in purely optical surveys due to their lack of outburst behavior. The eROSITA telescope aboard the Spektr-RG (SRG) mission is conducting an all-sky X-ray…

An overview is given of the properties of the various kinds of quasi-periodic luminosity modulations observed in cataclysmic variables (CVs). The two principal types, known in the CV literature as dwarf nova oscillations and quasi-periodic…

Astrophysics · Physics 2010-12-13 Brian Warner , Patrick A. Woudt

We present a new time-series VI CCD photometry of the globular cluster NGC 6397, from which we obtained and analysed the light curves of 35 variables carefully identified in the cluster field. We assessed the membership of the variables…

Solar and Stellar Astrophysics · Physics 2021-06-02 J. A. Ahumada , A. Arellano Ferro , I. Bustos Fierro , C. Lázaro , M. A. Yepez , K. P. Schroeder , J. Calderón

We report on the results of a long time photometric monitoring of the two metal poor Galactic globular clusters M22 and IC4499 searching for long period variables (LPVs) on the upper giant branch. We detected 22 new LPVs in the field of M22…

Solar and Stellar Astrophysics · Physics 2015-06-18 Anand Sahay , Thomas Lebzelter , Peter Wood

Cataclysmic variables (CVs) are the most numerous population among the Galactic objects emitting in hard X-rays. Most probably, they are responsible for the extended hard X-ray emission of the Galactic ridge and the central Galactic…

High Energy Astrophysical Phenomena · Physics 2022-02-23 Valery F. Suleimanov , Victor Doroshenko , Klaus Werner

We present a reanalysis of far-ultraviolet (FUV) observations of the globular cluster NGC 2808 obtained with the Hubble Space Telescope. These data were first analyzed by Brown and coworkers, with an emphasis on the bright, blue horizontal…

Astrophysics · Physics 2009-11-10 A. Dieball , C. Knigge , D. R. Zurek , M. M. Shara , K. S. Long

A deep (R ~ 19.5) photographic Halpha Survey of the southern Galactic Plane was recently completed using the UK Schmidt Telescope at the AAO. In addition, we have recently started a similar, CCD-based survey of the northern Galactic Plane…

Astrophysics · Physics 2011-03-10 Andrew Witham , Christian Knigge , Janet Drew , Paul Groot , Robert Greimel , Quentin Parker
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