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Correlated variability of the reflection fraction with the X-ray flux and spectral index for Mrk 478

Barua, Samuzal and Jithesh, V. and Misra, Ranjeev and Medhi, Biman J. and Adegoke, Oluwashina (2022) Correlated variability of the reflection fraction with the X-ray flux and spectral index for Mrk 478. Monthly Notices of the Royal Astronomical Society, 517 (1). pp. 801-807. ISSN 0035-8711. doi:10.1093/mnras/stac2690.

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The X-ray spectrum of Mrk 478 is known to be dominated by a strong soft excess that can be described using relativistic blurred reflection. Using observations from XMM–Newton, AstroSat, and Swift, we show that for the long-term (∼years) and intermediate-term (days to months) variability, the reflection fraction is anticorrelated with the flux and spectral index, which implies that the variability is due to the hard X-ray producing corona moving closer to and further from the black hole. Using flux-resolved spectroscopy of the XMM–Newton data, we show that the reflection fraction has the same behaviour with flux and index on short time-scales of hours. The results indicate that both the long- and short-term variability of the source is determined by the same physical mechanism of strong gravitational light bending causing enhanced reflection and low flux as the corona moves closer to the black hole.

Item Type:Article
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URLURL TypeDescription
Barua, Samuzal0000-0002-5248-2422
Jithesh, V.0000-0002-6449-9643
Misra, Ranjeev0000-0002-7609-2779
Medhi, Biman J.0000-0002-3448-8150
Adegoke, Oluwashina0000-0002-5966-4210
Additional Information:We thank the anonymous referee for the constructive comments and suggestions that improved this paper. SB acknowledges Inter-University Centre for Astronomy and Astrophysics (IUCAA) for the visiting program and providing technical support to conduct this research. We also thank Professor Gulab C. Dewangan for the useful discussion and support. SB, RM, and VJ thank Indian Space Research Organisation (ISRO) for observing the source and providing the data at Indian Space Science Data Centre (ISSDC). This research has also made use of data obtained through the High Energy Astrophysics Science Archive Research Center Online Service, provided by the NASA/GODDARD SPACE FLIGHT CENTER.
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Indian Space Research OrganisationUNSPECIFIED
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Record Number:CaltechAUTHORS:20221024-125854800.15
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ID Code:117546
Deposited By: Research Services Depository
Deposited On:01 Nov 2022 20:47
Last Modified:01 Nov 2022 20:47

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