Hard X-ray emission of the microquasar GX 339-4 in the low/hard state

Warning The system is temporarily closed to updates for reporting purpose.

Joinet, Angelique and Jourdain, Elizabeth and Malzac, Julien and Roques, Jean Pierre and Corbel, Stephane and Rodriguez, Jerome and Kalemci, Emrah (2007) Hard X-ray emission of the microquasar GX 339-4 in the low/hard state. Astrophysical Journal, 657 (issue 1 part 1). pp. 400-408. ISSN 0004-637X (Print) 1538-4357 (Online)

PDF - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader

Official URL: http://dx.doi.org/10.1086/510326


We present the analysis of the high-energy emission of the Galactic black hole binary GX 339-4 in a low/hard state at the beginning of its 2004 outburst. The data from 273 ks of INTEGRAL observations, spread over 4 weeks, are analyzed, along with the existing simultaneous RXTE HEXTE and PCA data. During this period, the flux increases by a factor of ~=3, while the spectral shape is quite unchanged, at least up to 150 keV. The high-energy data allow us to detect the presence of a high-energy cutoff, generally related to thermal mechanisms, and to estimate the plasma parameters in the framework of the Comptonization models. We found an electron temperature of 60-70 keV and an optical depth of around 2.5, with a rather low reflection factor (0.2-0.4). In the last observation, we detected a high-energy excess above 200 keV with respect to thermal Comptonization, while at lower energies the spectrum is practically identical to the previous one taken just 2 days before. This suggests that the low- and high-energy components have a different origin.

Item Type:Article
Uncontrolled Keywords:accretion, accretion disks; black hole physics; gamma rays : observations; stars : individual (GX 339-4); X-rays : binaries
Subjects:Q Science > QB Astronomy
Q Science > QC Physics
ID Code:6425
Deposited By:Emrah Kalemci
Deposited On:25 Oct 2007 23:43
Last Modified:17 Sep 2019 13:11

Repository Staff Only: item control page