Spectral Properties of the Soft X-Ray Transient MAXI J0637-430 Using AstroSat

Title

Spectral Properties of the Soft X-Ray Transient MAXI J0637-430 Using AstroSat

Creator

Thomas N.T.; Gudennavar S.B.; Misra R.; Bubbly S.G.

Description

Soft X-ray transients are systems that are detected when they go into an outburst, wherein their X-ray luminosity increases by several orders of magnitude. These outbursts are markers of the poorly understood change in the spectral state of these systems from the low/hard state to the high/soft state. We report the spectral properties of one such soft X-ray transient: MAXI J0637-430, with data from the SXT and LAXPC instruments on board the AstroSat mission. The source was observed for a total of ?60 ks in two observations on 2019 November 8 and 21 soon after its discovery. Flux-resolved spectral analysis of the source indicates the presence of a multicolor blackbody component arising from the accretion disk and a thermal Comptonization component. The stable low temperature (?0.55 keV) of the blackbody component points to a cool accretion disk with an inner disk radius of the order of a few hundred kilometers. In addition, we report the presence of a relativistically broadened Gaussian line at 6.4 keV. The disk-dominated flux and photon power-law index of ?2 and a constant inner disk radius indicate the source to be in the soft state. From the study we conclude that MAXI J0637-430 is a strong candidate for a black hole X-ray binary. 2022. The Author(s). Published by the American Astronomical Society.

Source

Astrophysical Journal, Vol-925, No. 2

Date

2022-01-01

Publisher

IOP Publishing Ltd

Coverage

Thomas N.T., Department of Physics and Electronics, CHRIST (Deemed to Be University), Central Campus, Bengaluru, 560029, India; Gudennavar S.B., Department of Physics and Electronics, CHRIST (Deemed to Be University), Central Campus, Bengaluru, 560029, India; Misra R., Inter-University Centre of Astronomy and Astrophysics, Post Bag 4, Ganeshkhind, Pune, 411007, India; Bubbly S.G., Department of Physics and Electronics, CHRIST (Deemed to Be University), Central Campus, Bengaluru, 560029, India

Rights

All Open Access; Gold Open Access; Green Open Access

Relation

ISSN: 0004637X

Format

Online

Language

English

Type

Article

Identifier

https://doi.org/10.3847/1538-4357/ac425e

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