Broadband X‐ray study of the galactic black hole binary 4U 1630‐47 with Suzaku

Abstract

We present the results from our Suzaku observations of the Galactic black hole binary 4U 1630−47. 4U 1630−47 was observed in the very high state (VHS) during the 2012 September-October outburst. The inner disk appears slightly truncated by comparison with a previous high/soft state (HSS) of this source, even by taking into account energetic coupling between the disk and corona. The spectra do not show the Doppler-shifted emission lines indicating baryonic jets that were seen four days previously in an XMM-Newton observation, despite the source being in a similar state. There are no significant absorption lines from highly ionized iron ions. We also observed 4U 1630−47 in the HSS simultaneously with Suzaku and NuSTAR in an early epoch of the 2015 outburst. All Suzaku spectra in the HSS show variable iron-K absorption line features. We find that the ionization state of the disk wind rapidly increased when the continuum showed significant spectral hardening. This behavior is consistent with that expected from a thermally driven wind.

Evolution of Thermally Driven Disk Wind in the Black Hole Binary 4U 1630–47 Observed with Suzaku and NuSTAR

“…In this paper, we present the results of simultaneous observations of 4U 1630−47 with Suzaku and NuSTAR on three occasions during the 2015 outburst. A part of the preliminary results were reported in Hori et al (2016), which should be superseded by this work. Combining with the Suzaku results in the 2007 outburst, we examine the evolution of the iron-K absorption lines in the HSS.…”