TRUNCATION OF THE INNER ACCRETION DISK AROUND A BLACK HOLE AT LOW LUMINOSITY
- Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720-7450 (United States)
- Department of Physics and Mathematics, Aoyama Gakuin University, Sagamihara, Kanagawa 229-8558 (Japan)
- AIM-Unite Mixte de Recherche CEA-CNRS-Universite Paris VII, UMR 7158, CEA-Saclay, Service d'Astrophysique, 91191 Gif-sur-Yvette Cedex (France)
- Department of Physics and Astronomy, University of Iowa, Van Allen Hall, Iowa City, IA 52242 (United States)
- Sabanci University, Orhanli-Tuzla, Istanbul, 34956 (Turkey)
- European Space Astronomy Centre, Apartado/P.O. Box 78, Villanueva de la Canada, E-28691 Madrid (Spain)
Most black hole binaries show large changes in X-ray luminosity caused primarily by variations in mass accretion rate. An important question for understanding black hole accretion and jet production is whether the inner edge of the accretion disk recedes at low accretion rate. Measurements of the location of the inner edge (R {sub in}) can be made using iron emission lines that arise due to fluorescence of iron in the disk, and these indicate that R {sub in} is very close to the black hole at high and moderate luminosities (approx>1% of the Eddington luminosity, L {sub Edd}). Here, we report on X-ray observations of the black hole GX 339 - 4 in the hard state by Suzaku and the Rossi X-ray Timing Explorer that extend iron line studies to 0.14% L {sub Edd} and show that R {sub in} increases by a factor of >27 over the value found when GX 339 - 4 was bright. The exact value of R {sub in} depends on the inclination of the inner disk (i), and we derive 90% confidence limits of R {sub in} > 35R{sub g} at i = 0{sup 0} and R {sub in} > 175R{sub g} at i = 30{sup 0}. This provides direct evidence that the inner portion of the disk is not present at low luminosity, allowing for the possibility that the inner disk is replaced by advection- or magnetically dominated accretion flows.
- OSTI ID:
- 21389311
- Journal Information:
- Astrophysical Journal (Online), Vol. 707, Issue 1; Other Information: DOI: 10.1088/0004-637X/707/1/L87; ISSN 1538-4357
- Country of Publication:
- United States
- Language:
- English
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THE TRUNCATED DISK FROM SUZAKU DATA OF GX 339-4 IN THE EXTREME VERY HIGH STATE
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Related Subjects
COSMOLOGY AND ASTRONOMY
ACCRETION DISKS
ADVECTION
BLACK HOLES
FLUORESCENCE
INCLINATION
IRON
LUMINOSITY
MASS
STARS
X RADIATION
ELECTROMAGNETIC RADIATION
ELEMENTS
EMISSION
IONIZING RADIATIONS
LUMINESCENCE
MASS TRANSFER
METALS
OPTICAL PROPERTIES
PHOTON EMISSION
PHYSICAL PROPERTIES
RADIATIONS
TRANSITION ELEMENTS