Publication Date:
2014-04-06
Description:
We present a broad-band spectral analysis of the joint XMM–Newton and Nuclear Spectroscopic Telescope Array observational campaign of the narrow-line Seyfert 1 SWIFT J2127.4+5654, consisting of 300 ks performed during three XMM–Newton orbits. We detect a relativistic broadened iron Kα line originating from the innermost regions of the accretion disc surrounding the central black hole, from which we infer an intermediate spin of $a = 0.58^{+0.11}_{-0.17}$ . The intrinsic spectrum is steep ( = 2.08 ± 0.01) as commonly found in narrow-line Seyfert 1 galaxies, while the cutoff energy ( $E_{\rm c}=108^{+11}_{-10}$ keV) falls within the range observed in broad-line Seyfert 1 galaxies. We measure a low-frequency lag that increases steadily with energy, while at high frequencies, there is a clear lag following the shape of the broad Fe K emission line. Interestingly, the observed Fe K lag in SWIFT J2127.4+5654 is not as broad as in other sources that have maximally spinning black holes. The lag amplitude suggests a continuum-to-reprocessor distance of about 10–20 r g . These timing results independently support an intermediate black hole spin and a compact corona.
Print ISSN:
0035-8711
Electronic ISSN:
1365-2966
Topics:
Physics