Investigating the characteristics of x-ray emission from Black Hole Binaries V4641 Sagittarii and V1033 Scorpii from Chandra Data

Abstract

X-ray emission processes in binary systems with early-type stars present a much more complex scenario, in which magnetic fields also play a key role. Despite a very wide range of phenomena that have been observed to occur and have offered real breakthroughs in black hole binary systems, the details of accretion and extremely large X-ray emitting structures are not properly modeled. We investigated the characteristics of X-ray emission from black hole binaries V4641 Sagittarii and V1033 Scorpii. We specifically determined the X-ray intensities and periodicities for these binary systems as well as the responsible X-ray emission mechanisms in the lower energy regime. Chandra data were obtained from the public archive and reprocessed using CIAO version 4.12 and CALDB version 4.9.3 for analysis. Power density spectrum (PDS) was performed on the light curves to determine the periodicities while intensities were also calculated. The two objects (V4641 Sagittarii and V1033 Scorpii) have their intensities between 0.1 × 10 −2 and 0.8 × 10 −2 counts per second with periodicities of between 20 to 25 seconds for V4641 Sgr and 50 to 100 for V1033 Sco. Two emission mechanisms are considered responsible for the production of X-rays in these systems, namely blackbody radiation and thermal Bresstraulung. Bremsstrahlung emission is thought to be the dominant emission mechanism, due to particles accreted from the secondary star and accelerated towards the black hole. As the accreted materials approach the innermost stable circular orbit, however, blackbody radiation takes over to emit soft X-rays (0.5 to 2 KeV) near the black hole. Due to Chandra capabilities of 0.3 to 10 keV, only soft X-rays could be investigated. It is therefore recommended that data from higher energy missions be used to study the properties of the systems in hard X-ray regime.