Open AccessExtremely weak reflection features in the X‐ray spectrum of XTE J1118+480: possible evidence for X‐ray‐emitting jets?
Author(s) -
Miller J. M.,
Ballantyne D. R.,
Fabian A. C.,
Lewin W. H. G.
Publication year - 2002
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2002.05636.x
Subject(s) - physics , x ray , astrophysics , reflection (computer programming) , spectrum (functional analysis) , astronomy , optics , quantum mechanics , computer science , programming language
We have simultaneously fitted Chandra and RXTE spectra of the Galactic black hole XTE J1118+480 with three models for X‐ray reflection. We explored a range of accretion disc ionizations (log ξ= 1–4;ξ= L X / nR 2 ) and iron abundances (0.10–1.00). Our fits with the constant‐density ionized disc models of Ross & Fabian indicate that ≤0.5 per cent (90 per cent confidence upper limit) of the observed flux is reflected. Fits with the pexrav model of Magdziarz & Zdziarski indicate that the two‐dimensional solid angle (Ω/2π) subtended by the disc relative to a central source of incident hard X‐rays is 0.01 +0.06 −0.01 . A combination of the high inclination ( i = 81°) , Comptonization, and bulk velocities may contribute to the low reflection fractions we have measured. The results are also consistent with extended jets being the source of the hard X‐ray flux, as the disc would then represent a small solid angle as seen from the emission region.