The evolution of the corona in MAXI J1535-571 through type-C quasi-periodic oscillations with Insight-HXMT
Abstract
Type-C quasi-periodic oscillations (QPOs) in black hole X-ray transients can appear when the source is in the low-hard and hard-intermediate states. The spectral-timing evolution of the type-C QPO in MAXI J1535-571 has been recently studied with Insight-HXMT. Here, we fit simultaneously the time-averaged energy spectrum, using a relativistic reflection model, and the fractional rms and phase-lag spectra of the type-C QPOs, using a recently developed time-dependent Comptonization model when the source was in the intermediate state. For the first time, we show that the time-dependent Comptonization model can successfully explain the X-ray data up to 100 keV. We find that in the hard-intermediate state the frequency of the type-C QPO decreases from 2.6 to 2.1 Hz, then increases to 3.3 Hz, and finally increases to ~9 Hz. Simultaneously with this, the evolution of corona size and the feedback fraction (the fraction of photons up-scattered in the corona that return to the disc) indicates the change of the morphology of the corona. Compared with contemporaneous radio observations, this evolution suggests a possible connection between the corona and the jet when the system is in the hard-intermediate state and about to transit into the soft-intermediate state.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- May 2022
- DOI:
- 10.1093/mnras/stac690
- arXiv:
- arXiv:2203.05308
- Bibcode:
- 2022MNRAS.512.2686Z
- Keywords:
-
- accretion;
- accretion discs;
- stars: black holes;
- stars: individual: MAXI J1535-571;
- X-rays: binaries;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 11 pages, 6 figures, accepted for publication in MNRAS