Spectral and temporal features of GX 13+1 as revealed by AstroSat
- Title
- Spectral and temporal features of GX 13+1 as revealed by AstroSat
- Creator
- Giridharan L.; Thomas N.T.; Gudennavar S.B.; Bubbly S.G.
- Description
- GX 13+1, a neutron star low-mass X-ray binary that exhibits the properties of both atoll and Z sources, is studied using data from Soft X-ray Telescope and Large Area X-ray Proportional Counter (LAXPC) onboard AstroSat. The source traces a ? shaped track in its hardness-intensity diagram (HID). Spectral modelling of the data in the 0.7-30.0 keV energy range, with the model-+, yields orbital inclination angle (?) of 77. Flux resolved spectral analysis reveals the ? shaped pattern in the plots of spectral parameters kTe, kTbb, and ? versus Fbol, closely resembling the pattern traced in LAXPC HID. This indicates changes in the spectral properties of the corona and the boundary layer/accretion disc. Assuming that the accretion disc truncates at the AlfvCrossed D sign n radius, the upper limit of the magnetic field strength (B) at the poles of neutron star in GX 13+1 is calculated to be 5.10 108 G (for kA = 1 and ? = 0.1), which is close to that of atoll sources. Furthermore, thickness of the boundary layer is estimated to be 5.70 km, which results in the neutron star radius value of 14.50 km. Quasi-periodic oscillations (QPOs) at 56 4 and 54 4 Hz are detected in Regions D and E of HID, respectively. The frequencies of these QPOs are similar to the characteristic frequency of horizontal branch oscillation and these do not exhibit a positive correlation with mass accretion rate.
- Source
- Monthly Notices of the Royal Astronomical Society, Vol-527, No. 4, pp. 11855-11865.
- Date
- 2024-01-01
- Publisher
- Oxford University Press
- Subject
- accretion, accretion discs; stars: neutron; X-rays: individual: GX 13+1; X-rays:binaries
- Coverage
- Giridharan L., Department of Physics and Electronics, CHRIST University, Karnataka, Bangalore, 560029, India; Thomas N.T., Department of Physics and Electronics, CHRIST University, Karnataka, Bangalore, 560029, India; Gudennavar S.B., Department of Physics and Electronics, CHRIST University, Karnataka, Bangalore, 560029, India; Bubbly S.G., Department of Physics and Electronics, CHRIST University, Karnataka, Bangalore, 560029, India
- Rights
- All Open Access; Hybrid Gold Open Access
- Relation
- ISSN: 358711; CODEN: MNRAA
- Format
- Online
- Language
- English
- Type
- Article
Collection
Citation
Giridharan L.; Thomas N.T.; Gudennavar S.B.; Bubbly S.G., “Spectral and temporal features of GX 13+1 as revealed by AstroSat,” CHRIST (Deemed To Be University) Institutional Repository, accessed February 25, 2025, https://archives.christuniversity.in/items/show/13337.