The evolution of the corona in MAXI J1535−571 through type-C quasi-periodic oscillations with Insight-HXMT. Issue 2 (12th March 2022)

• Record Type: Journal Article
• Authors: Zhang, Yuexin; Méndez, Mariano; García, Federico; Zhang, Shuang-Nan; Karpouzas, Konstantinos; Altamirano, Diego; Belloni, Tomaso M; Qu, Jinlu; Zhang, Shu; Tao, Lian; Zhang, Liang; Huang, Yue; Kong, Lingda; Ma, Ruican; Yu, Wei; Rawat, Divya; Bellavita, Candela
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 512:Issue 2(2022)
• Page Start: 2686
• Page End: 2696
• Publication Date: 2022-03-12
• Subjects: accretion, accretion discs -- stars: black holes -- stars: individual: MAXI J1535−571 -- X-rays: binaries; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stac690
• Languages: English
• ISSNs: 0035-8711

Abstract

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.