SimultaneousChandraandRXTESpectroscopy of the Microquasar H1743−322: Clues to Disk Wind and Jet Formation from a Variable Ionized Outflow

We observed the bright phase of the 2003 outburst of the Galactic black holecandidate H 1743-322 in X-rays simultaneously with Chandra and RXTE on fouroccasions. The Chandra/HETGS spectra reveal narrow, variable (He-like) Fe XXVand (H-like) Fe XXVI resonance absorption lines. In the first observation, theFe XXVI line has a FWHM of 1800 +/- 400 km/s and a blue-shift of 700 +/- 200km/s, suggesting that the highly ionized medium is an outflow. Moreover, the FeXXV line is observed to vary significantly on a timescale of a few hundredseconds in the first observation, which corresponds to the Keplerian orbitalperiod at approximately 1 E+4 gravitational radii. Our models for theabsorption geometry suggest that a combination of geometric effects andchanging ionizing flux are required to account for the large changes in lineflux observed between observations, and that the absorption likely occurs at aradius less than 1 E+4 radii for a 10 Msun black hole. Viable models for theabsorption geometry include cyclic absorption due to an accretion diskstructure, absorption in a clumpy outflowing disk wind, or possibly acombination of these two. If the wind in H 1743-322 has unity filling factor,the highest implied mass outflow rate is 20 percent of the Eddington massaccretion rate. This wind may be a hot precursor to the Seyfert-like,outflowing "warm absorber" geometries recently found in the Galactic blackholes GX 339-4 and XTE J1650-500. We discuss these findings in the context ofionized Fe absorption lines found in the spectra of other Galactic sources, andconnections to warm absorbers, winds, and jets in other accreting systems.Comment: 18 pages, 7 figures, 5 in color, subm. to ApJ. Uses emulateapj.sty and apjfonts.st