A burst from the direction of UZ Fornacis with XMM-Newton

Abstract

The XMM-Newton pointing towards the magnetic cataclysmic variable UZ For finds the source to be a factor > 10^3 fainter than previous EXOSAT and ROSAT observations. The source was not detected for the majority of a 22 ksec exposure with the EPIC cameras, suggesting that the accretion rate either decreased, or stopped altogether. However a 1.1 ksec burst was detected from UZ For during the observation. Spectral fits favour optically thin, kT = 4.4 keV thermal emission. Detection of the burst by the on-board Optical Monitor indicates that this was most probably an accretion event. The 0.1-10 keV luminosity of 2.1 x 10^30 erg/s is typical for accretion shock emission from high state polars and would result from the potential energy release of ~ 10^16 g of gas. There is no significant soft excess due to reprocessing in the white dwarf atmosphere.

arXiv comment7 pages, 2 postscript figures, ApJL, in press

References in corpus (4)

• Complex Absorption and Reflection of a Multi-temperature Cyclotron-Bremsstrahlung X-ray Cooling Shock in BY Cam
• High-Speed Energy-Resolved STJ Photometry of the Eclipsing Binary UZ For
• First XMM-Newton observations of strongly magnetic cataclysmic variables I: spectral studies of DP Leo and WW Hor
• ROSAT Observations of the Flare Star CC Eri

Cited by in corpus (10)

• The Spectra and Variability of X-ray Sources in a Deep Chandra Observation of the Galactic Center
• The intriguing nature of the high energy gamma ray source XSSJ12270-4859
• XMM-Newton observations of polars in low accretion states
• The NuSTAR Hard X-ray Survey of the Norma Arm Region
• XMM-Newton observes flaring in the polar UZ For during a low state
• The fight for accretion: discovery of intermittent mass transfer in BB Doradus in the low state
• Radio detections of two unusual cataclysmic variables in the VLA Sky Survey
• High-speed photometry of the eclipsing polar UZ Fornacis
• Rapid variability of accretion in AM Herculis
• Detection of an energetic flare from the M5V secondary star in the Polar MQ Dra