NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-03-26 T18:22:43 PDT
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Notes for object NGC 4992

1 note(s) found in NED.


1. 2009A&A...502..457G
Re:NGC 4992
A.1.7 NGC 4992 The Sy classification of this source comes from Bodaghee et al.
(2007) and references therein. Comastri et al. (2007) present a broad-band
Suzaku spectral analysis, and infer an extreme reflection component with R>5 and
a possible relativistically-blurred Fe line, indicative of disk-dominated
reflection. This can be naturally explained by relativistic light-bending on to
the inner disk, which enhances reflection and suppresses the incident power law
at infinity (Miniutti et al. 2004). The fraction of AGN described by this
light-bending model is still unknown, though increasing numbers of sources are
being discovered, and the hard X-ray background spectrum can also accommodate a
non-negligible fraction of light-bent source in the Universe (see for instance
Miniutti et al. 2004; Gandhi et al. 2007; Miniutti et al. 2007, and references
therein).
Although the majority of intrinsic power law photons may be bent towards the
event horizon and never escape the black hole's gravitational sphere of
influence, the relevant luminosity in our case is the X-ray flux that is
incident on the distant torus clouds, i.e. the (absorption-corrected) power
observed at infinity. Using the model of Comastri et al. (2007) yields L_2-10_ =
1.7 x 10^43^ erg s^-1^. If part of the high reflection stems instead from
decreased transmission efficiency by heavy obscuring material or from strong
time variability, then this estimate will be a lower limit (cf. Ueda et al.
2007).


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