aagi101.pdf (415.57 kB)

# Discovery of a bright X-ray transient in the Galactic Center with XMM-Newton

journal contribution
posted on 24.10.2012, 09:16 by D. Porquet, V. Burwitz, B. Aschenbach, P. Predehl, N. Grosso, I. L. Andronov, R. S. Warwick
We report the discovery of a bright X-ray transient object, XMMU J174554.4-285456 , observed in outburst with XMM-Newton on October 3, 2002, and located at 6.3 $^{\prime}$ from Sgr A* , the supermassive black hole at the Galactic center. This object exhibits a very large X-ray luminosity variability of a factor of about 1300 between two X-ray observations separated by four months. The X-ray spectrum is best fitted by a power-law with a photon index of $1.6\pm0.2$ and absorption column density of $14.1^{+1.6}_{-1.4}\times10^{22}$ cm -2. This large absorption suggests this source is located at the distance of the Galactic center, i.e., 8 kpc. The 2-10 keV luminosity is about $1.0 \times 10^{35}\,(d/{\rm 8\,kpc})^{2}$ erg s -1. A pulsation period of about 172 s is hinted by the timing analysis. The X-ray properties strongly suggest a binary system with either a black hole or a neutron star for the compact object.

## Citation

Astronomy & Astrophysics, 2005, 430 (1)

## Version

VoR (Version of Record)

## Published in

Astronomy & Astrophysics

## Publisher

EDP Sciences for European Southern Observatory (ESO)

0004-6361

2005

24/10/2012

## Publisher version

http://www.aanda.org/articles/aa/abs/2005/04/aagi101/aagi101.html

en