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

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 ($l = 357^\circ, \, b = -2^\circ)$ 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 $((2.5 \, ^{+4.3} _{-2.5}) \times 10^{22}$ atom cm-2) soft (photon index $2.70 \pm 0.09$) power-law model, consistent with H 1743-322 being in a high/soft state.