English

AstroSat View of the Neutron Star Low-mass X-Ray Binary GX 5-1

High Energy Astrophysical Phenomena 2024-11-19 v2

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, kTinkT_{in} \sim0.46 and a thermal Comptonization model. It is found that the optical depth of the corona drops from \sim6.68 in HB to \sim2.74 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 \sim12-46 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.

Keywords

Cite

@article{arxiv.2404.02782,
  title  = {AstroSat View of the Neutron Star Low-mass X-Ray Binary GX 5-1},
  author = {Shyam Prakash V P and Vivek K. Agrawal},
  journal= {arXiv preprint arXiv:2404.02782},
  year   = {2024}
}

Comments

11 pages, 5 figures, 4 tables, Accepted in Astrophysical Journal