RXTE monitoring of GRS1758-258

Presenter: Maria Obst

GRS 1758-258 is the least well studied of the three persistent black hole X-ray binaries in our Galaxy. It is also one of only two known black hole candidates, including all black hole transients, which shows a decrease of its 3-10keV flux when entering the thermally dominated soft state, rather than an increase. We present the spectral evolution of GRS 1758-258 from RXTE-PCA observations spanning a time of about 10 years from 1997 to 2007. The results of this analysis are compared to that of the INTEGRAL monitoring of the source. We will also compare the long term behaviour of the source to that of the bright persistent black hole X-ray binary Cygnus X-1 and discuss the observed state transitions in the light of physical scenarios for black hole transitions.

POTTSCHMIDT, Katja (CRESST/UMBC/GSFC)
LOHFINK, Anne (UMD)
WILMS, Joern (Remeis/ECAP)
SMITH, David M. (SCIPP, UCSC)
TOMSICK, John A. (SSL, UCB)
KREYKENBOHM, Ingo (Remeis/ECAP)