Search Publications
Multi-epoch hard X-ray view of Compton-thick AGN Circinus Galaxy
Gandhi, Poshak; Ricci, Claudio; Kayal, Abhijit +4 more
The circumnuclear material around active galactic nuclei (AGNs) is one of the essential components of the obscuration-based unification model. However, our understanding of the circumnuclear material in terms of its geometrical shape, structure, and its dependence on accretion rate is still debated. In this paper, we present the multi-epoch broad-…
NGC 4388: a test case for relativistic disc reflection and Fe K fluorescence features
LaMassa, S.; Yaqoob, Tahir; Tzanavaris, P.
We present a new analysis of the Suzaku X-ray spectrum of the Compton-thin Seyfert 2 galaxy NGC 4388. The spectrum above ~2 keV can be described by a remarkably simple and rather mundane model, consisting of a uniform, neutral spherical distribution of matter, with a radial column density of $2.58\pm 0.02 \times 10^{23} \ \rm cm^{-2}$, and an Fe a…
Lamp-post with an outflow and the hard state of Cyg X-1
Szanecki, Michał; Niedźwiecki, Andrzej; Klepczarek, Łukasz
Relativistic reflection observed in the hard states of accreting black holes (BH) often shows a weak amplitude relative to the main Comptonization component, which may result from either a disc truncation or a non-isotropy of the X-ray source, e.g. due to a motion away from the reflector. We investigate here the latter case, assuming that the X-ra…
Broad-band X-ray spectral study of nuclear structure in local obscured radio galaxies
Ueda, Yoshihiro; Ricci, Claudio; Ogawa, Shoji +6 more
Radio galaxies are a key population to understand the importance of relativistic jets in active galactic nucleus (AGN) feedback. We present the results of a systematic, broad-band X-ray spectral analysis of hard X-ray selected radio galaxies to investigate their nuclear structures. In this study, we focus on the seven most radio-loud, X-ray obscur…
Unravelling optical and X-ray properties of the disc-dominated intermediate polar IGR J15094-6649
Pandey, J. C.; Scaringi, Simone; Schwope, Axel +5 more
We present analyses of an Intermediate Polar, IGR J15094-6649, based on the archival optical data obtained from the Transiting Exoplanet Survey Satellite (TESS) and X-ray data obtained from the Suzaku, NuSTAR, and Neil Gehrels Swift Observatory (Swift). Present analysis confirms and refines the previously reported spin period of IGR J15094-6649 as…
Hot accretion flows in low-luminosity active galactic nuclei in NGC 4258 and NGC 7213
Szanecki, Michał; Niedźwiecki, Andrzej; Wojaczyński, Rafał
We study the high energy emission of two active galactic nuclei (AGNs), NGC 4258 and NGC 7213. We directly apply the general-relativistic hot flow model, KERRFLOW, to the archival BeppoSAX, NuSTAR, and Suzaku observations of these objects. Most of these data sets indicate that about 10-20 per cent of the accretion power is used for the direct heat…