THE 2003 OUTBURST OF THE X-RAY TRANSIENT H1743-322: COMPARISONS WITH THE BLACK HOLE MICROQUASAR XTE J1550-564

The bright X-ray transient H1743-322 was observed daily by the Rossi X-ray Timing Explorer during most of its eight-month outburst in 2003. We present a detailed spectral analysis and a supporting timing analysis of all of these data, and we discuss the behavior and evolution of the source in terms of the three principal X-ray states defined by Remillard and McClintock. These X-ray results are complemented by Very Large Array data obtained at six frequencies that provide quite complete coverage of the entire outburst cycle at 4.860 GHz and 8.460 GHz. We also present photometric data and finding charts for the optical counterpart in both outburst and quiescence. We closely compare H1743-322 to the well-studied black hole X-ray transient XTE J1550-564 and find the behaviors of these systems to be very similar. As reported elsewhere, both H1743-322 and XTE J1550-564 are relativistic jet sources and exhibit a pair of high-frequency quasi-periodic oscillations with a 3: 2 frequency ratio. The many striking similarities between these two sources argue strongly that H1743-322 is a black hole binary, although presently no dynamical data exist to support this conclusion.