2012年7月
THE TRUNCATED DISK FROM SUZAKU DATA OF GX 339-4 IN THE EXTREME VERY HIGH STATE
ASTROPHYSICAL JOURNAL
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- 巻
- 753
- 号
- 1
- 開始ページ
- 65
- 終了ページ
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1088/0004-637X/753/1/65
- 出版者・発行元
- IOP PUBLISHING LTD
We report on the geometry of accretion disk and high-energy coronae in the strong Comptonization state (the very high/steep power law/hard intermediate state) based on a Suzaku observation of the famous Galactic black hole GX 339-4. These data were taken just before the peak of the 2006-2007 outburst, and the average X-ray luminosity in the 0.7-200 keV band is estimated to be 2.9 x 10(38) erg s(-1) for a distance of 8 kpc. We fit the spectrum with both simple (independent disk and corona) and sophisticated (energetically coupled disk and corona) models; all fits imply that the underlying optically thick disk is truncated significantly before the innermost stable circular orbit around the black hole. We show this directly by a comparison with similar broadband data from a disk-dominated spectrum at almost the same luminosity observed by XMM-Newton and RXTE 3 days after the Suzaku observation. During the Suzaku observation, the quasi-periodic oscillation (QPO) frequency changes from 4.3 Hz to 5.5 Hz, while the spectrum softens. The energetically coupled model gives a corresponding 5%+/- 8% decrease in the derived inner radius of the disk. While this is not significant, it is consistent with the predicted change in QPO frequency from the Lense-Thirring precession of the hot flow interior to the disk and/or a deformation mode of this flow, as a higher QPO frequency implies a smaller size scale for the corona. This is consistent with the truncated disk extending further inward toward the black hole.
- リンク情報
- ID情報
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- DOI : 10.1088/0004-637X/753/1/65
- ISSN : 0004-637X
- eISSN : 1538-4357
- Web of Science ID : WOS:000305632500065