| Name: Daneshwar Bhandari |
| Affiliation: SoS in Physics and Astrophysics Pt. Ravishankar Shukla University Raipur (C.G.) |
| Conference ID: ASI2026_107 |
| Title: Spectral and Temporal Analysis of GS 1826-238 with XPoSat/XSPECT |
| Abstract Type: Poster |
| Abstract Category: High Energy Phenomena, Fundamental Physics and Astronomy |
| Author(s) and Co-Author(s) with Affiliation: Daneshwar Bhandari(SoS in Physics and Astrophysics Pt. Ravishankar Shukla University, Raipur (C.G.), India), Dr. Vivek Kumar Agrawal(Space Astronomy Group, ISITE Campus, U. R. Rao Satellite Centre, ISRO, Bengaluru 560037, India), Dr. Nand Kumar Chakradhari(SoS in Physics and Astrophysics Pt. Ravishankar Shukla University, Raipur (C.G.), India) |
| Abstract: We present a detailed spectral and temporal study of the low-mass X-ray binary (LMXB) GS 1826-238 using observations from the XSPECT instrument onboard XPoSat in the 0.8-15.0 keV energy range. GS 1826-238 is a well-known neutron-star atoll source and a prototypical clocked burster, exhibiting remarkably regular thermonuclear (Type I) X-ray bursts. Long-term monitoring with MAXI over the past 6-8 years shows that the source has remained persistently active in a soft spectral state.
The temporal analysis reveals the presence of Type I X-ray bursts, characterized by a rapid rise and exponential decay profile. The hardness-intensity diagram (HID) indicates that the source predominantly occupies the banana state, which is characteristic of atoll sources accreting at relatively high mass accretion rates. Two Type I X-ray bursts were detected during the observation.
We investigated the evolution of spectral and timing properties along the HID, providing insights into the accretion geometry and emission processes in the soft state. The X-ray spectral properties were studied as a function of position along the banana branch, revealing systematic changes in the continuum parameters that reflect variations in the mass accretion rate. Time-resolved spectroscopy of the Type I X-ray bursts shows a clear evolution of the blackbody temperature and emitting radius during the burst decay, consistent with unstable helium-rich nuclear burning on the neutron-star surface. |
