AstroSat View of the Neutron Star Low-mass X-Ray Binary GX 5-1
Abstract
We present the spectral and timing study of the bright NS-LMXB GX 5-1 using \textit{\textit{AstroSat}/LAXPC} and \textit{SXT} observations conducted in the year 2018. During the observation, the source traces out the complete HB and NB of the Z-track in the HID. Understanding the spectral and temporal evolution of the source along the 'Z' track can probe the accretion process in the vicinity of a neutron star. Spectral analysis was performed in the 0.7-20 keV energy range for different segments in the HID using a multi-temperature disc black body with an average temperature, $kT_{in} \sim$0.46 and a thermal Comptonization model. It is found that the optical depth of the corona drops from $\sim$6.68 in HB to $\sim$2.74 in NB. The Timing analysis using the LAXPC instrument indicates the presence of quasi-periodic oscillations in HB, NB, and the hard apex of the Z-track. The observed QPO frequencies are similar to the characteristic frequencies of horizontal branch and normal branch oscillations. The HBO frequency increase from $\sim$12-46 Hz towards the hard apex. The timing studies conducted in soft and hard band indicate the association of HBO and NBO origin with the non-thermal component. Further research could explore the implications of this relationship for understanding the dynamics of accretion onto neutron stars.
- Publication:
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arXiv e-prints
- Pub Date:
- April 2024
- DOI:
- 10.48550/arXiv.2404.02782
- arXiv:
- arXiv:2404.02782
- Bibcode:
- 2024arXiv240402782P
- Keywords:
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- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 11 pages, 5 figures, 4 tables