We carried out systematic analysis of 8 black hole candidates (BHCs) and 1 neutron star (NS) in the low/hard states, using archival RXTE data which cover an energy range of 2-250 keV. As a result, we found that the photon index is distributed in the range of 1.2–1.8, and the cutoff energy is more than 40 keV. As the X-ray luminosity increases, both the photon index and the cutoff energy tend to become smaller. This may suggest that high energy electrons are cooled by inverse Compton scattering from soft photons. No clear differences between BHC and NS were found.
URL : http://ptp.ipap.jp/link?PTPS/155/443/
DOI : 10.1143/PTPS.155.443