Abstract Details
| Name: AJITH BALU Affiliation: Raman Research Institute Conference ID: ASI2025_231 Title : Study of X-ray absorption characteristics of high-mass X-ray binaries in different intensity levels with MAXI/GSC Authors and Co-Authors : Ajith Balu 1, Kinjal Roy 1, Hemanth Manikantan 1, Abhisek Tamang 1,2, Biswajit Paul 1 Abstract Type : Poster Abstract Category : High Energy Phenomena, Fundamental Physics and Astronomy Abstract : High-mass X-ray binaries (HMXBs) are luminous X-ray sources that emit electromagnetic radiation by gravitationally accreting matter from its companion star. The X-ray, originating near the NS, can get absorbed/reprocessed by the environment, especially the stellar wind of the companion star. An all-sky monitor such as MAXI/GSC, which has been in operation for over a decade, has significant sensitivity to study the long-term characteristics of HMXBs. Such sources can also exhibit periodic and aperiodic intensity variations. We performed orbital-phase-resolved spectroscopy for both the intensity-averaged and intensity-resolved data to explore any intensity-dependent characteristics of the source. Any orbital-phase-dependent spectral characteristics found in the long-term data of MAXI/GSC must be persistent in the binary system. For Cen X-3, we found clear asymmetric variation in photoelectric absorption, with respect to mid-phase (𝜙orb = 0.5), across the orbit of the source. Asymmetric absorption features cannot originate from a symmetric stellar wind. The absorption column density is a tracer of binary matter distribution, so any asymmetry should result from an asymmetric distribution of matter in the binary system. While the matter distribution is more symmetric at higher intensity levels, we find that the asymmetry in matter distribution is most pronounced for the lowest intensity level of Cen X-3. The differences in the orbital-phase-dependence of absorption for different intensity levels suggest the presence of asymmetric features like an accretion wake, photoionization wake, or tidal stream, which are most prominent at the lowest intensity level for Centaurus X-3. We will also discuss results from a similar study carried out in another HMXB called SMC X-1. |