The XMM-Newton/Chandra monitoring campaign on the Galactic center region
R. Wijnands(1), J.J.M. in 't Zand(2), M. Rupen(3, 4), T. Maccarone(5), J. Homan(6), R. Cornelisse(5), R. Fender(5, 1), J. Grindlay(7), M. van der Klis(1), E. Kuulkers(8), C.B. Markwardt(4, 9), J.C.A. Miller-Jones(1), Q.D. Wang(10)
(1) Astronomical Institute ``Anton Pannekoek'', University of Amsterdam, Kruislaan 403, 1098 SJ, The Netherlands
(2) SRON National Institute for Space Research, Sorbonnelaan 2, 3584 CA, Utrecht, The Netherlands
(3) National Radio Astronomy Observatory, 1003 Lopezville Road, Socorro, NM 87801, USA
(4) NASA, Goddard Space Flight Center, Greenbelt, MD 20711, USA
(5) School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ, UK
(6) Center for Space Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
(7) Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
(8) ISOC, ESA/ESAC, Urb. Villafranca del Castillo, P.O. Box 50727, 28080 Madrid, Spain
(9) Department of Astronomy, University of Maryland, College Park, MD 20742, USA (10) Astronomy Department, University of Massachusetts, Amherst, MA 01003, USA
Paper: A&A, submitted
Abstract:
We present the first results of our X-ray monitoring
campaign on a 1.7 square degree region centered on Sgr A* using the
X-ray satellites XMM-Newton and Chandra. The purpose of
this campaign is to monitor the X-ray behavior (below 10 keV) of X-ray
sources (both persistent and transient) which are too faint to be
detected by monitoring instruments aboard satellites currently in
orbit (e.g., Rossi X-ray Timing Explorer; INTEGRAL). Our
first monitoring observations (using the HRC-I aboard Chandra)
were obtained on June 5, 2005. Most of the sources detected could be
identified with foreground sources, such as X-ray active stars. In
addition we detected two persistent X-ray binaries (1E 1743.1-2843;
1A 1742-294), two faint X-ray transients (GRS 1741.9-2843; XMM
J174457-2850.3), as well as a possible new transient source at a
luminosity of a few times 1034 erg s-1. We report on the
X-ray results on these systems and on the non detection of the
transients in follow-up radio data using the Very Large Array. We
discuss how our monitoring campaign can help to improve our
understanding of the different types of X-ray transients (i.e., the
very faint ones).
Preprints available from the authors at rudy@science.uva.nl
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or the raw TeX (no figures) if you click here.
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