SUZAKU BROADBAND SPECTROSCOPY OF SWIFT J1753.5-0127 IN THE LOW-HARD STATE

Journal Article · Wed Jan 20 04:00:00 EST 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/709/1/358· OSTI ID:21392333

Reynolds, Mark T; Miller, Jon M ^[1]; Homan, Jeroen ^[2]; Miniutti, Giovanni ^[3]

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1. Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States)
2. MIT Kavli Institute for Astrophysics and Space Research, 70 Vasser Street, Cambridge, MA 02139 (United States)
3. LAEX, Centro de Astrobiologia (CSIC-INTA), LAEFF, P.O. Box 78, E-28691, Villanueva de la Canada, Madrid (Spain)

We present Suzaku observations of the Galactic black hole candidate Swift J1753.5-0127 in the low-hard state (LHS). The broadband coverage of Suzaku enables us to detect the source over the energy range 0.6-250 keV. The broadband spectrum (2-250 keV) is found to be consistent with a simple power-law (GAMMA approx 1.63). In agreement with previous observations of this system, a significant excess of soft X-ray flux is detected consistent with the presence of a cool accretion disk. Estimates of the disk inner radius infer a value consistent with the innermost stable circular orbit (ISCO; R{sub in} approx< 6R{sub g} , for certain values of, e.g., N{sub H}, i), although we cannot conclusively rule out the presence of an accretion disk truncated at larger radii (R{sub in} approx 10-50R{sub g} ). A weak, relativistically broadened iron line is also detected, in addition to disk reflection at higher energy. However, the iron-K line profile favors an inner radius larger than the ISCO (R{sub in} approx 10-20R{sub g} ). The implications of these observations for models of the accretion flow in the LHS are discussed.

• OSTI ID: 21392333
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 709; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ACCRETION DISKS
BLACK HOLES
ELECTROMAGNETIC RADIATION
ELEMENTS
ENERGY RANGE
IONIZING RADIATIONS
IRON
KEV RANGE
METALS
ORBITS
RADIATIONS
REFLECTION
SOFT X RADIATION
SPECTRA
SPECTROSCOPY
TRANSITION ELEMENTS
X RADIATION