Suzaku Observations of the Black Hole H1743-322 in Outburst

TL;DR

This study used Suzaku to observe the black hole candidate H1743-322 during its low/hard state, analyzing its X-ray spectrum to investigate the presence of ionized absorption lines and disk reflection features, revealing state-dependent wind activity.

Contribution

First detailed Suzaku spectral analysis of H1743-322 in low/hard state, highlighting the absence of certain absorption lines and possible disk reflection features, advancing understanding of accretion states.

Findings

No narrow Fe XXV and Fe XXVI absorption lines detected.

Upper limits on absorption line equivalent widths established.

Possible detection of disk reflection features including Fe K emission.

Abstract

We observed the Galactic black hole candidate H1743-322 with Suzaku for approximately 32 ksec, while the source was in a low/hard state during its 2008 outburst. We collected and analyzed the data with the HXD/PIN, HXD/GSO and XIS cameras spanning the energy range from 0.7-200 keV. Fits to the spectra with simple models fail to detect narrow Fe XXV and Fe XXVI absorption lines, with 90% confidence upper limits of 3.5 eV and 2.5 eV on the equivalent width, respectively. These limits are commensurate with those in the very high state, but are well below the equivalent widths of lines detected in the high/soft state, suggesting that disk winds are partially state-dependent. We discuss these results in the context of previous detections of ionized Fe absorption lines in H1743-322 and connections to winds and jets in accreting systems. Additionally, we report the possible detection of disk reflection features, including an Fe K emission line.