An Extreme X-Ray Disk Wind in the Black Hole Candidate IGR J17091-3624

Authors

A. L. King, University of Michigan
J. M. Miller, University of Michigan
J. Raymond, Smithsonian Astrophysical Observatory
A. C. Fabian, Institute of Astronomy, University of Cambridge
C. S. Reynolds, University of Maryland
T. R. Kallman, Laboratory for High Energy Astrophysics, NASA Goddard Space Flight Center
D. Maitra, University of Michigan
E. M. Cackett, Institute of Astronomy, University of CambridgeFollow
M. P. Rupen, National Radio Astronomy Observatory

Document Type

Article

Abstract

Chandra spectroscopy of transient stellar-mass black holes in outburst has clearly revealed accretion disk winds in soft, disk-dominated states, in apparent anti-correlation with relativistic jets in low/hard states. These disk winds are observed to be highly ionized, dense, and to have typical velocities of ~1000 km s^-1 or less projected along our line of sight. Here, we present an analysis of two Chandra High Energy Transmission Grating spectra of the Galactic black hole candidate IGR J17091-3624 and contemporaneous Expanded Very Large Array (EVLA) radio observations, obtained in 2011. The second Chandra observation reveals an absorption line at 6.91 ± 0.01 keV associating this line with He-like Fe XXV requires a blueshift of 9300⁺⁵⁰⁰ _-400 km s^-1 (0.03c, or the escape velocity at 1000 R _Schw). This projected outflow velocity is an order of magnitude higher than has previously been observed in stellar-mass black holes, and is broadly consistent with some of the fastest winds detected in active galactic nuclei. A potential feature at 7.32 keV, if due to Fe XXVI, would imply a velocity of ~14, 600 km s^-1 (0.05c), but this putative feature is marginal. Photoionization modeling suggests that the accretion disk wind in IGR J17091-3624 may originate within 43,300 Schwarzschild radii of the black hole and may be expelling more gas than it accretes. The contemporaneous EVLA observations strongly indicate that jet activity was indeed quenched at the time of our Chandra observations. We discuss the results in the context of disk winds, jets, and basic accretion disk physics in accreting black hole systems.

Disciplines

Cosmology, Relativity, and Gravity | Stars, Interstellar Medium and the Galaxy

Comments

NOTICE IN COMPLIANCE WITH PUBLISHER POLICY: ©2012, American Astronomical Society. Available at: doi:10.1088/2041-8205/746/2/L20

Recommended Citation

An Extreme X-Ray Disk Wind in the Black Hole Candidate IGR J17091–3624

A. L. King et al. 2012 ApJ 746 L20