A&A 427, 101-105 (2004)
DOI: 10.1051/0004-6361:20041637
XMM-Newton observation of the Seyfert 1.8 ESO 113-G010: Discovery of a highly redshifted iron line at 5.4 keV
D. Porquet1, J. N. Reeves2, 3, P. Uttley2 and T. J. Turner2, 41 Max-Planck-Institut für extraterrestrische Physik, Postfach 1312, 85741 Garching, Germany
e-mail: dporquet@mpe.mpg.de
2 Laboratory for High Energy Astrophysics, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
3 Universities Space Research Association, 7501 Forbes Boulevard, Suite 206, Seabrook, MD 20706, USA
4 Joint Center for Astrophysics, Physics Department, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
(Received 2 June 2004 / Accepted 17 July 2004 )
Abstract
We present a spectral analysis of the Seyfert 1.8
ESO 113-G010
observed with XMM-Newton for 4 ks.
The spectrum shows a soft excess below 0.7 keV and more interestingly
a narrow emission Gaussian line at 5.4 keV (in its rest-frame), most probably
originating from a redshifted iron K
line.
No significant line at or above 6.4 keV is found contrary to other
objects showing redshifted lines, ruling out a strong blue-wing to the
line profile. The line is detected at 99% confidence, from performing
Monte Carlo simulations which fully account for the range of energies
where a narrow iron line is likely to occur.
The energy of the line could indicate emission from
relativistic (0.17-0.23 c) ejected matter moving away from the observer,
as proposed for Mrk 766 by Turner et al. (2004, ApJ, 603, 62).
Alternatively, the emission from a narrow annulus
at the surface of the accretion disk
is unlikely due to the very small inclination angle
(i.e. less than 10
) required to explain the narrow,
redshifted line in this intermediate Seyfert galaxy.
However emission from a small, localized
hot-spot on the disk, occurring within a fraction of a complete disk orbit,
could also explain the redshifted line.
This scenario would be directly testable in a longer
observation, as one would see significant variations in the energy and
intensity of the line within an orbital timescale.
Key words: galaxies: active -- galaxies: quasars: general -- X-rays: general -- line: formation -- X-rays: individual: ESO 113-G010
SIMBAD Objects
© ESO 2004