Far Ultraviolet observations of the High Mass X-ray Binary 4U1700-37/HD153919

Abstract

The high-mass X-ray binary 4U1700-37/HD153919 has been observed with FUSE to study the effect of the X-ray source on the stellar wind of the primary. Phase dependent changes in the wind lines have been observed, indicating the creation of a X-ray ionization zone in the stellar wind. The X-ray luminosity of 4U1700-37 ionizes much of the wind and leaves a Stromgren zone. This disrupts the resonance-line acceleration of the wind in portions of the orbit, quenching the wind and disrupting the mass flow. This effect was found for the first time in 4U1700-37. This so-called Hatchett-McCray (HM) effect had been predicted for 4U1700-37, but was not previously detected.