INTEGRAL observations of the black hole candidate H 1743-322 in outburst

Abstract

INTEGRAL made 3 observations in 2003 April of the black hole candidate H 1743-322 during the rising part, and close to the maximum, of an outburst. H 1743-322 was previously observed in outburst in 1977-1978. The source is located in a crowded region of the sky (l = 357^o, b = -2^o) and at least 18 sources are clearly detected in the field of view of the ISGRI gamma-ray imager during a 277 ks exposure. These are well known persistent X-ray binary sources and 3 transient sources in outburst. The combined 5-200 keV JEM-X and SPI spectrum of H 1743-322 is well fit with an absorbed ((2.5 ^+4.3 _-2.5) x 10²² atom cm^-2) soft (photon index 2.70 +/- 0.09) power-law model, consistent with H 1743-322 being in a high/soft state.

Based on observations with INTEGRAL, an ESA project with instruments and science data centre funded by ESA member states (especially the PI countries: Denmark, France, Germany, Italy, Switzerland, Spain), Czech Republic and Poland and with the participation of Russia and the USA.