Re-examining the XMM-Newton Spectrum of the Black Hole Candidate XTE J1652-453. (arXiv:1207.0682v1 [astro-ph.HE])

Re-examining the XMM-Newton Spectrum of the Black Hole Candidate XTE J1652-453. (arXiv:1207.0682v1 [astro-ph.HE]):
The XMM-Newton spectrum of the black hole candidate XTE J1652-453 shows a
broad and strong Fe K-alpha emission line, generally believed to originate from
reflection of the inner accretion disc. These data have been analysed by
Hiemstra et al. (2011) using a variety of phenomenological models. We
re-examine the spectrum with a self-consistent relativistic reflection model. A
narrow absorption line near 7.2 keV may be present, which if real is likely the
Fe XXVI absorption line arising from highly ionised, rapidly outflowing disc
wind. The blue shift of this feature corresponds to a velocity of about 11100
km/s, which is much larger than the typical values seen in stellar-mass black
holes. Given that we also find the source to have a low inclination (i < 32
degrees; close to face-on), we would therefore be seeing through the very base
of outflow. This could be a possible explanation for the unusually high
velocity. We use a reflection model combined with a relativistic convolution
kernel which allows for both prograde and retrograde black hole spin, and treat
the potential absorption feature with a physical model for a photo-ionised
plasma. In this manner, assuming the disc is not truncated, we could only
constrain the spin of the black hole in XTE J1652-453 to be less than ~ 0.5
Jc/GM^{2} at the 90% confidence limit.