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Issue A&A
Volume 414, Number 1, January IV 2004
Page(s) 155 - 161
Section Galactic structure and dynamics
DOI http://dx.doi.org/10.1051/0004-6361:20031635



A&A 414, 155-161 (2004)
DOI: 10.1051/0004-6361:20031635

The high energy emission line spectrum of NGC 1068

G. Matt1, S. Bianchi1, M. Guainazzi2 and S. Molendi3

1  Dipartimento di Fisica, Università degli Studi Roma Tre, via della Vasca Navale 84, 00146 Roma, Italy
2  XMM-Newton Science Operation Center/RSSD-ESA, Villafranca del Castillo, Spain
3  IASF-CNR, Via Bassini 15, 20133, Milano, Italy

(Received 21 August 2003 / Accepted 17 October 2003 )

Abstract
We present and discuss the high energy ( E>4 keV) XMM-Newton spectrum of the Seyfert 2 galaxy, NGC 1068. Possible evidence for flux variability in both the neutral and ionized reflectors with respect to a BeppoSAX observation taken 3.5 years before is found. Several Fe and Ni emission lines, from both neutral and highly ionized material, are detected. The intensity of the iron K $\alpha$ Compton shoulder implies that the neutral reflector is Compton-thick, likely the visible inner wall of the $N_{\rm H} > 10^{25}$ cm -2 absorber. From the equivalent width of the ionized iron lines a column density of a few $\times 10^{21}$ cm -2 is deduced for the hot ionized reflector. Finally, an iron (nickel) overabundance, when compared to solar values, of about 2 (4) with respect to lower  Z elements, is found.


Key words: galaxies: individual: NGC 1068 -- galaxies: Seyfert -- X-rays: galaxies

Offprint request: G. Matt, matt@fis.uniroma3.it

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