| Name: | Lavanya S |
| Affiliation: | Christ Deemed to be University |
| Conference ID : | ASI2024_549 |
| Title : | Analysis of type I X-ray bursts from 4U 1735−44 using AstroSat data |
| Authors : | S. Lavanya, Neal Titus Thomas, S. B. Gudennavar, S. G. Bubbly
|
| Authors Affiliation: | S. Lavanya, Neal Titus Thomas, S. B. Gudennavar, S. G. Bubbly Affiliation (CHRIST Deemed to be University, Bengaluru-560029, India) |
| Mode of Presentation: | Oral |
| Abstract Category : | High Energy Phenomena, Fundamental Physics and Astronomy |
| Abstract : | Low mass X-ray binaries hosting weakly magnetized neutron stars are classified as Z and atoll sources, based on the tracks traced on their hardness-intensity diagram/colour-colour diagram and the correlation between their spectral and temporal variability. Atoll sources are known to exhibit type I X-ray bursts that are characterized by a fast rise exponential decay in their lightcurves. These bursts are surface phenomena and help to constrain the physical parameters of the system. 4U 1735−44 is one such atoll source located in the Galactic bulge. It is a frequent burster and has exhibited the longest-ever type I X-ray burst recorded. The source was observed during two different epochs on 2018 July 31 and 2021 August 24, using the Soft X-ray Telescope and Large Area X-ray Proportional Counter instruments on-board AstroSat. The source exhibited a type I X-ray burst during each of these observations. We present here the spectral analysis of the persistent and burst emission from the source in the 0.7−20.0 keV energy range. Spectral analysis of the persistent emission revealed the source to have a cool accretion disk truncated at a large distance from the neutron star. Time-resolved spectral analysis of the burst showed that the source underwent photospheric radius expansion during both the bursts. Using the obtained spectral properties, we inferred the source distance to be 10.6 (+0.3/−0.4) kpc, and the radius of the neutron star was calculated to be 11.8 (+1.3/−1.2) km. |
