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 hole candidate H1743-322 in X-rays simultaneously with Chandra and RXTE on four occasions. The Chandra HETGS spectra reveal narrow, variable (He-like) Fe XXV and (H-like) Fe XXVI resonance absorption lines. In the first observation, the Fe XXVI line has a FWHM of 1800 ± 400 km s -1 and a blueshift of 700 ± 200 km s -1 , suggesting that the highly ionized medium is an outflow. Moreover, the Fe XXV line is observed to vary significantly on a timescale of a few hundred seconds in the first observation, which corresponds to the Keplerian orbital period at approximately 10 4 r g (where r g = GM / c 2 ). Our models for the absorption geometry suggest that a combination of changing ionizing flux and geometric effects are required to account for the large changes in line flux observed between observations and that the absorption likely occurs at a radius between 10 2 r g and 10 4 r g for a 10 M ☉ black hole. We suggest that the absorption occurs in an inhomogeneous accretion disk wind. If the wind in H1743-322 has unity filling factor, the highest implied mass outflow rate is 5% of the Eddington mass accretion rate. The observed wind may be a hotter, more ionized version of the Seyfert-like, outflowing warm absorber geometries recently found in the Galactic black holes GX 339-4 and XTE J1650-500. We discuss these findings in the context of ionized Fe absorption lines found in the spectra of other Galactic sources, and connections to warm absorbers, winds and jets in other accreting systems.