Properties of the type-C quasi-periodic oscillations of MAXI J1348-630 using NICER
Abstract
MAXI J348-630 is a black-hole X-ray transient discovered in January 2019. At the end of the outburst and before reaching the quiescence state, MAXI J1348-630 underwent several reflares during which the source remained in the low/hard state. This system was observed with the Neutron Star Interior Composition Explorer (NICER) on an almost daily basis from the beginning of the outburst and during all its reflares. We present the study of the properties of the type-C quasi-periodic oscillation (type-C QPO) detected during the 2019 outburst of MAXI J1348-630 and the first reflare using NICER data. We show that the properties of the type-C QPO during the first reflare of MAXI J1348-630 are similar to those of other type-C QPOs observed in other sources during an outburst. This suggests that type-C QPOs in both outbursts and reflares are driven by the same physical mechanisms. We model the energy-dependent fractional rms amplitude and phase lags of the type-C QPO using a time-dependent Comptonisation model of Karpouzas et al. (2020), further improved by Bellavita et al. (2022) to include seed photons from the accretions disc. We fit simultaneously the rms and lag spectra of the type-C QPO and study the evolution of the properties of the Comptonising region that produces the QPO during the whole outburst and reflare of MAXI J1348-630.
- Publication:
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44th COSPAR Scientific Assembly. Held 16-24 July
- Pub Date:
- July 2022
- Bibcode:
- 2022cosp...44.2355A