Spectral and type I X-ray burst studies of 4U 1702-429 using AstroSat observations
Abstract
4U 1702-429, an atoll-type neutron star low-mass X-ray binary, was observed twice by the AstroSat/Soft X-ray Telescope (SXT) and Large Area X-ray Proportional Counters (LAXPC-20) on 2018 April 27 and 2019 August 8. Persistent emission spectra of the source were well fitted with the model combination - constant × tbabs (thcomp × diskbb+powerlaw). The parameters obtained from the spectral analysis revealed the source to be in a hard spectral state during the observations. Time-resolved spectral analyses were performed on the three type I X-ray bursts detected from the source. Burst analysis showed that the source underwent a photospheric radius expansion. Consequently, the radius of the neutron star and distance to the source (with isotropic and anisotropic burst emission) were obtained as 12.65$\substack{+0.90\-0.86}$ km and 6.92$\substack{+0.16\-0.09}$ and 8.43$\substack{+0.20\-0.10}$ kpc, respectively.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- April 2024
- DOI:
- 10.1093/mnras/stae636
- Bibcode:
- 2024MNRAS.529.2234V
- Keywords:
-
- accretion;
- accretion discs;
- stars: neutron;
- X-rays: binaries;
- X-rays: bursts;
- X-rays: individual: 4U 1702-429