X-ray spectroscopy of the high-mass X-ray binary 4U 1700-37

Abstract

We present the first results of a monitoring campaign of the high-mass X-ray binary system 4U 1700-37/HD 153919, carried out with XMM-Newton in February 2001. The system was observed four times, covering 37% of one 3-41-day orbit. The lightcurve shows strong flares, commonly observed in this source. We focus on three intervals in which the data are not affected by pile up: the eclipse, the eclipse egress and a low-flux part around orbital phase phi similar to 0.28. We discuss the soft excess, the emission lines observed in eclipse and eclipse egress and the consequences for the size of the ionisation zone.