Tracking the jet-like corona of black hole Swift J1727.8-1613 during a flare state through Type-C quasi-periodic oscillations
| Autor: | Liao, Jie, Chang, Ning, Cui, Lang, Jiang, Pengfei, Mou, Didong, Huang, Yongfeng, An, Tao, Ho, Luis C., Feng, Hua, Fu, Yu-Cong, Cao, Hongmin, Liu, Xiang |
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| Rok vydání: | 2024 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | Type-C quasi-periodic oscillations (QPOs) in black hole X-ray transients typically manifest in the low-hard and hard-intermediate states. This study presents a detailed spectral and temporal analysis of the black hole candidate Swift J1727.8-1613 using NICER observations from August and September 2023, with a focus on the first flare period. The time-averaged spectra, along with the rms and phase-lag spectra of the QPOs, were jointly fitted using the time-dependent Comptonization model \text{vkompthdk} to examine the geometry of the corona during this flare. The results provide a comprehensive view of the QPO, where we detected type-C QPOs with a centroid frequency increasing from 0.32 Hz to 2.63 Hz, while it elevated when it entered the flare state, and its energy spectral properties as they evolved during the first flare period. Correlations between spectral and temporal properties suggest that type-C QPOs are primarily modulated by Lense-Thirring precession. Based on simultaneous radio observations indicating discrete jet ejections, we propose, for the first time, a scenario where the temporarily extended corona contracts vertically from approximately 2714 km to less than 900 km, overlying the inner accretion disc, with a transient jet seemingly being launched. The corona then recovers to nearly 2000 km by the end of the first flare period of Swift J1727.8-1613, rather than undergoing horizontal changes. A phenomenological analysis of the corona scenario during this flare period was also conducted. Comment: 16 pages, 6 figures, 3 tables, Submitted to ApJ |
| Databáze: | arXiv |
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