Gespeichert in:
| Hauptverfasser: | , , , , |
|---|---|
| Format: | Preprint |
| Veröffentlicht: |
2026
|
| Schlagworte: | |
| Online-Zugang: | https://arxiv.org/abs/2605.15857 |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| _version_ | 1866910223682240512 |
|---|---|
| author | Chatterjee, Rwitika Agrawal, Vivek Kumar Prakash, V. P. Shyam Vadodariya, Koushal V, Radhakrishna |
| author_facet | Chatterjee, Rwitika Agrawal, Vivek Kumar Prakash, V. P. Shyam Vadodariya, Koushal V, Radhakrishna |
| contents | XSPECT instrument on-board XPoSat mission is a soft X-ray spectrometer sensitive in the energy band 0.8$-$15 keV. XSPECT has observed several bright neutron star low mass X-ray binaries since launch. Two well known sources, Aql X-1 and 4U 1608-52 which are soft X-ray transients, were observed by XPoSat during the decay phase of their recent outbursts in September 2024 and February 2025 respectively. During XSPECT observations, 4U 1608-52 exhibited a superburst which is a long duration thermonuclear burst, believed to be triggered by carbon burning. We carry out a detailed spectro-temporal analysis of the superburst, tracing its onset, rise, and decay over the next several hours. Using time-resolved spectroscopy, we probe the spectral evolution of the source and find that the persistent emission is suppressed during the superburst and the emission can be described by a gradually cooling blackbody component. The superburst was preceded by a precursor burst which is a normal type-I X-ray burst. We also observe a type-I burst $\sim 5$ days after the superburst, indicating resumption of burst activities which is typically quenched after a superburst. Aql X-1 also exhibited a type-I burst during XSPECT observations. The persistent emission of both the sources can be fitted using a combination of blackbody and disk blackbody emission or, alternatively, using a disk Comptonized by an optically thick plasma. Using the latter model, we find a clear flux dependence of the Comptonization parameters, with both the sources exhibiting harder spectra at higher accretion rates. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2605_15857 |
| institution | arXiv |
| publishDate | 2026 |
| record_format | arxiv |
| spellingShingle | Tracing the outburst decay of soft X-ray transients Aql X-1 and 4U 1608-52 with XSPECT Chatterjee, Rwitika Agrawal, Vivek Kumar Prakash, V. P. Shyam Vadodariya, Koushal V, Radhakrishna High Energy Astrophysical Phenomena XSPECT instrument on-board XPoSat mission is a soft X-ray spectrometer sensitive in the energy band 0.8$-$15 keV. XSPECT has observed several bright neutron star low mass X-ray binaries since launch. Two well known sources, Aql X-1 and 4U 1608-52 which are soft X-ray transients, were observed by XPoSat during the decay phase of their recent outbursts in September 2024 and February 2025 respectively. During XSPECT observations, 4U 1608-52 exhibited a superburst which is a long duration thermonuclear burst, believed to be triggered by carbon burning. We carry out a detailed spectro-temporal analysis of the superburst, tracing its onset, rise, and decay over the next several hours. Using time-resolved spectroscopy, we probe the spectral evolution of the source and find that the persistent emission is suppressed during the superburst and the emission can be described by a gradually cooling blackbody component. The superburst was preceded by a precursor burst which is a normal type-I X-ray burst. We also observe a type-I burst $\sim 5$ days after the superburst, indicating resumption of burst activities which is typically quenched after a superburst. Aql X-1 also exhibited a type-I burst during XSPECT observations. The persistent emission of both the sources can be fitted using a combination of blackbody and disk blackbody emission or, alternatively, using a disk Comptonized by an optically thick plasma. Using the latter model, we find a clear flux dependence of the Comptonization parameters, with both the sources exhibiting harder spectra at higher accretion rates. |
| title | Tracing the outburst decay of soft X-ray transients Aql X-1 and 4U 1608-52 with XSPECT |
| topic | High Energy Astrophysical Phenomena |
| url | https://arxiv.org/abs/2605.15857 |