Estimation of the black hole spin in LMC X-1 using AstroSat

Title

Estimation of the black hole spin in LMC X-1 using AstroSat

Creator

Mudambi S.P.; Rao A.; Gudennavar S.B.; Misra R.; Bubbly S.G.

Description

LMC X-1, a persistent, rapidly rotating, extra-galactic, black hole X-ray binary (BHXB) discovered in 1969, has always been observed in its high soft state. Unlike many other BHXBs, the black hole mass, source distance, and binary orbital inclination are well established. In this work, we report the results of simultaneous broad-band spectral studies of LMC X-1 carried out using the data from Soft X-ray Telescope and Large Area X-ray Proportional Counter aboard AstroSat as observed on 2016 November 26 and 2017 August 28. The combined spectrum was modelled with a multicolour blackbody emission (diskbb), a Gaussian along with a Comptonization component (simpl) in the energy range 0.7-30.0 keV. The spectral analysis revealed that the source was in its high soft state (? = 2.67+0.24-0.24 and ? = 2.12+0.19-0.20) with a hot disc (kTin = 0.86+0.01-0.01 and kTin = 0.87+0.02-0.02). Thermal disc emission was fitted with a relativistic model (kerrbb) and spin of the black hole was estimated to be 0.93+0.01-0.01 and 0.93+0.04-0.03 (statistical errors) for the two Epochs through X-ray continuum-fitting, which agrees with the previous results. 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.

Source

Monthly Notices of the Royal Astronomical Society, Vol-498, No. 3, pp. 4404-4410.

Date

2020-01-01

Publisher

Oxford University Press

Subject

accretion, accretion discs; black hole physics; X-rays: binaries; X-rays: individual: stars

Coverage

Mudambi S.P., Department of Physics and Electronics, CHRIST (Deemed to Be University), Bangalore Central Campus, Bengaluru, 560029, India; Rao A., Department of Physics and Astronomy, Faculty of Physical Sciences and Engineering, University of Southampton, Southampton, S017 1BJ, United Kingdom; Gudennavar S.B., Department of Physics and Electronics, CHRIST (Deemed to Be University), Bangalore Central Campus, Bengaluru, 560029, India; Misra R., Inter-University Centre for Astronomy and Astrophysics, Ganeshkind, Pune, 411007, India; Bubbly S.G., Department of Physics and Electronics, CHRIST (Deemed to Be University), Bangalore Central Campus, Bengaluru, 560029, India

Rights

All Open Access; Green Open Access

Relation

ISSN: 358711; CODEN: MNRAA

Format

Online

Language

English

Type

Article

Identifier

https://doi.org/10.1093/mnras/staa2656

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