A NuSTAR and Swift view of the hard state of MAXI J1813−095. Issue 2 (20th May 2022)

• Record Type: Journal Article
• Authors: Jiang, Jiachen; Buisson, Douglas J K; Dauser, Thomas; Fabian, Andrew C; Fürst, Felix; Gallo, Luigi C; Harrison, Fiona A; Parker, Michael L; Steiner, James F; Tomsick, John A; Ubach, Santiago; Walton, Dominic J
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 514:Issue 2(2022)
• Page Start: 1952
• Page End: 1960
• Publication Date: 2022-05-20
• Subjects: accretion, accretion discs -- black hole physics -- X-rays: binaries; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stac1401
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: We present an analysis of the NuSTAR and Swift spectra of the black hole candidate MAXI J1813−095 in a failed-transition outburst in 2018. The NuSTAR observations show evidence of reflected emission from the inner region of the accretion disc. By modelling the reflection component in the spectra, we find a disc inner radius of R in < 7 r g . This result suggests that either a slightly truncated disc or a non-truncated disc forms at a few per cent of the Eddington limit in MAXI J1813−095. Our best-fitting reflection models indicate that the geometry of the innermost accretion remains consistent during the period of NuSTAR observations. The spectral variability of MAXI J1813−095 from multi-epoch observations is dominated by the variable photon index of the Comptonization emission.