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Title: SWIFT AND RXTE OBSERVATIONS OF THE BLACK HOLE TRANSIENT GX 339-4 IN THE HARD STATE BETWEEN OUTBURSTS

We use simultaneous Swift and RXTE observations of the black hole binary GX 339-4 to measure the inner radius of its accretion disk in the hard state down to 0.4% L{sub Edd} via modeling of the thermal disk emission and the relativistically broadened iron line. For the luminosity range covered in this work, our results rule out a significantly truncated disk at 100-1000 R{sub g} as predicted by the advection-dominated accretion flow paradigm. The measurements depend strongly on the assumed emission geometry, with most results providing no clear picture of radius evolution. If the inclination is constrained to roughly 20 Degree-Sign , however, the measurements based on the thermal disk emission suggest a mildly receding disk at a luminosity of 0.4% L{sub Edd}. The iron abundance varies between {approx}1 and 2 solar abundances, with the i = 20 Degree-Sign results indicating a negative correlation with luminosity, though this is likely due to a change in disk illumination geometry.
Authors:
 [1] ;  [2] ;  [3] ;  [4]
  1. 602 Van Allen Hall, University of Iowa, IA 52242 (United States)
  2. Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720-7450 (United States)
  3. 702 Van Allen Hall, University of Iowa, IA 52242 (United States)
  4. Solar Terrestrial Environment Laboratory, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan)
Publication Date:
OSTI Identifier:
22133855
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 774; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABUNDANCE; ACCRETION DISKS; ADVECTION; BLACK HOLES; EMISSION; ILLUMINANCE; INCLINATION; IRON; LUMINOSITY; SIMULATION; TRANSIENTS