Bibcode
González-Martín, O.; Masegosa, J.; Márquez, I.; Guainazzi, M.; Jiménez-Bailón, E.
Referencia bibliográfica
Astronomy and Astrophysics, Volume 506, Issue 3, 2009, pp.1107-1121
Fecha de publicación:
11
2009
Revista
Número de citas
166
Número de citas referidas
150
Descripción
We present the results of a homogeneous X-ray analysis for 82 nearby
low-ionisation, narrow emission-line regions (LINERs) selected from the
catalogue of Carrillo et al. (1999, Rev. Mex. Astron. Astrofis., 35,
187). All sources have available Chandra (68 sources) and/or XMM-Newton
(55 sources) observations. This is the largest sample of LINERs with
X-ray spectral data (60 out of the 82 objects), and it significantly
improves our previous analysis based on Chandra data for 51 LINERs
(Gonzalez-Martin et al. 2006b, A&A, 460, 45). It both increases the
sample size and adds XMM-Newton data. New models permit the inclusion of
double absorbers in the spectral fits. Nuclear X-ray morphology is
inferred from the compactness of detected nuclear sources in the hard
band (4.5-8.0 keV). Sixty per cent of the sample shows a compact nuclear
source and are classified as active galactic nucleus (AGN) candidates.
The spectral analysis indicates that best fits involve a composite
model: 1) absorbed primary continuum and 2) soft spectrum below 2 keV
described by an absorbed scatterer and/or a thermal component. The
resulting median spectral parameters and their standard deviations are
<Γ> = 2.11 ± 0.52, < kT> = 0.54 ± 0.30
keV, < log(NH1) > } = 21.32 {± 0.71 and < log(NH2)> }
= 21.93 {± 1.36. We complement our X-ray results with an analysis
of HST optical images and literature data on emission lines, radio
compactness, and stellar population. After adding all these
multiwavelength data, we conclude that evidence supports the AGN nature
of their nuclear engine for 80% of the sample (66 out of 82 objects).
Tables 1 to 15, and Appendices are only available in electronic form at
http://www.aanda.org