Disk emission and atmospheric absorption lines in black hole candidate 4U 1630-472

Abstract

We re-analyzed SUZAKU data of the black hole candidate 4U 1630-472 being in the high/soft state. We show that the continuum X-ray spectrum of 4U 1630-472 with iron absorption lines can be satisfactorily modeled by the spectrum from an accretion disk atmosphere. Absorption lines of highly ionized iron originating in hot accretion disk atmosphere can be an alternative or complementary explanation to the wind model usually favored for these type of sources. We model continuum and line spectra using a single model. Absorption lines of highly ionized iron can origin in upper parts of the disk atmosphere which is intrinsically hot due to high disk temperature. Iron line profiles computed with natural, thermal and pressure broadenings match very well observations. We showed that the accretion disk atmosphere can effectively produce iron absorption lines observed in 4U 1630-472 spectrum. Absorption line arising in accretion disk atmosphere is the important part of the observed line profile, even if there are also other mechanisms responsible for the absorption features. Nevertheless, the wind theory can be an artifact of the fitting procedure, when the continuum and lines are fitted as separate model components.

10 pages, 4 figures, accepted by Astronomy and Astrophysics

References in corpus (1)

• The Accretion Disk Wind in the Black Hole GRO J1655-40

Cited by in corpus (7)

• A Delayed Transition to the Hard State for 4U 1630-47 at the End of Its 2010 Outburst
• Chandra high-resolution spectra of 4U~1630-47: the disappearance of the wind
• AstroSat and Chandra view of the high soft state of 4U 1630-47 (4U 1630-472): evidence of the disk wind and a rapidly spinning black hole
• Detection of X-ray polarized emission and accretion-disk winds with IXPE and NICER in the black-hole X-ray binary 4U 1630-47
• Spectropolarimetric study of 4U 1630$-$47 in Steep Power law state with IXPE and NICER
• The XMM Newton spectra of the 2012 outburst of the black-hole candidate 4U 1630-47 revisited
• Accretion disc winds in X-ray binaries