The INTEGRAL Galactic Bulge monitoring program: Spectral study

Abstract

The center of the Milky Way is a region crowded with X-ray binaries of all kinds: High Mass X-ray Binaries (HMXBs) and Low Mass X-ray Binaries (LMXBs) containing neutron stars or black holes as the compact objects of the binary systems. It then provides a wealth of information on different sources when observed with a wide-field-of-view instrument such as IBIS/ISGRI or JEM-X onboard INTEGRAL. The INTEGRAL Galactic bulge monitoring program was born with the aim of investigating the variability and the transient activity on time scales of days to weeks and months of these sources, in the soft as well as the hard X-ray band [1]. We present here the results of the spectral analysis for eight presistently bright sources in the Galactic bulge that are covered by IBIS/ISGRI and JEM-X simultaneously for the first 3 observing periods (from 2005-02-17 until 2006-03-01), namely 1A 1742−294, 1E 1740.7−2942, 4U 1722−30, GRS 1758−258, GX 3+1, GX 354−0, GX 5−1, and SLX 1744−299/300.