Journal
ASTROPHYSICAL JOURNAL
Volume 555, Issue 1, Pages 483-488Publisher
UNIV CHICAGO PRESS
DOI: 10.1086/321450
Keywords
accretion, accretion disks; stars : individual (XTE J1118+480); X-rays : stars
Categories
Ask authors/readers for more resources
Based on recent multiwavelength observations of the new X-ray nova XTE J1118+480, we can place strong constraints on the geometry of the accretion flow in which a low/hard-state spectrum, characteristic of an accreting black hole binary, is produced. We argue that the absence of any soft blackbody-like component in the X-ray band implies the existence of an extended hot optically thin region, with the optically thick cool disk truncated at some radius We show that such a model can indeed R-tr greater than or similar to 55R(Schw). reproduce the main features of the observed spectrum: the relatively high optical to X-ray ratio, the sharp downturn in the far-UV band, and the hard X-ray spectrum. The absence of the disk blackbody component also underscores the requirement that the seed photons for thermal Comptonization be produced locally in the hot flow, e.g., via synchrotron radiation. We attribute the observed spectral break at similar to2 keV to absorption in a warm, partially ionized gas.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available