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Corona, Jet, and Relativistic Line Models for Suzaku/RXTE/Chandra-HETG Observations of the Cygnus X-1 Hard StateUsing Suzaku and the Rossi X-ray Timing Explorer (RXTE), we have conducted a series of four simultaneous observations of the galactic black hole candidate Cyg X-1 in what were historically faint and spectrally hard "low states". Additionally, all of these observations occurred near superior conjunction with our line of sight to the X-ray source passing through the dense phases of the "focused wind" from the mass donating secondary. One of our observations was also simultaneous with observations by the Chandra-High Energy Transmission Grating (HETG). These latter spectra are crucial for revealing the ionized absorption due to the secondary s focused wind. Such absorption is present and must be accounted for in all four spectra. These simultaneous data give an unprecedented view of the 0.8-300 keV spectrum of Cyg X-1, and hence bear upon both corona and X-ray emitting jet models of black hole hard states. Three models fit the spectra well: coronae with thermal or mixed thermal/non-thermal electron populations, and jets. All three models require a soft component that we fit with a low temperature disk spectrum with an inner radius of only a few tens of GM/c2. All three models also agree that the known spectral break at 10 keV is not solely due to the presence of reflection, but each gives a different underlying explanation for the augmentation of this break. Thus whereas all three models require that there is a relativistically broadened Fe line, the strength and inner radius of such a line is dependent upon the specific model, thus making premature line-based estimates of the black hole spin in the Cyg X-1 system. We look at the relativistic line in detail, accounting for the narrow Fe emission and ionized absorption detected by HETG. Although the specific relativistic parameters of the line are continuum-dependent, none of the broad line fits allow for an inner disk radius that is > 40 GM/c(sup 2).
Document ID
20110007962
Acquisition Source
Goddard Space Flight Center
Document Type
Preprint (Draft being sent to journal)
Authors
Nowak, Michael A. (Massachusetts Inst. of Tech. Cambridge, MA, United States)
Hanke, Manfred (Erlangen-Nuernberg Univ. Bamberg, Germany)
Trowbridge, Sarah N. (Massachusetts Inst. of Tech. Cambridge, MA, United States)
Markoff, Sera B. (Amsterdam Univ. Netherlands)
Wilms, Joern (Erlangen-Nuernberg Univ. Bamberg, Germany)
Pottschmidt, Katja (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Coppi, Paolo (Yale Univ. New Haven, CT, United States)
Maitra, Dipankar (Amsterdam Univ. Netherlands)
Davis, Jhn E. (Massachusetts Inst. of Tech. Cambridge, MA, United States)
Tramper, Frank (Amsterdam Univ. Netherlands)
Date Acquired
August 25, 2013
Publication Date
February 18, 2009
Subject Category
Astronomy
Funding Number(s)
CONTRACT_GRANT: SV3-73016
CONTRACT_GRANT: DLR 50 OR 0701
CONTRACT_GRANT: GO8-9036X
CONTRACT_GRANT: NNG06EO90A
CONTRACT_GRANT: NNX08AE23G
CONTRACT_GRANT: NNX07AF71G
Distribution Limits
Public
Copyright
Public Use Permitted.

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