Bibcode
González-Martín, O.; Masegosa, J.; Márquez, I.; Jiménez-Bailón, E.
Referencia bibliográfica
Black Holes from Stars to Galaxies -- Across the Range of Masses. Edited by V. Karas and G. Matt. Proceedings of IAU Symposium #238, held 21-25 August, 2006 in Prague, Czech Republic. Cambridge, UK: Cambridge University Press, 2007., pp.373-374
Fecha de publicación:
4
2007
Número de citas
1
Número de citas referidas
1
Descripción
Low-luminosity AGNs (LLAGNs), which make up the vast majority of the AGN
population, may yield important clues into the origin and evolution of
nuclear activity, constituting a perfect laboratory to investigate the
connection between galaxies in which the central black holes are active
and those in which they are quiescent. The precence of a compact X-ray
nucleus may provide evidences about their AGN nature. Chandra's
excellent resolution allows an investigation of the X-ray nuclear
properties of these galaxies. Low Ionization Nuclear-Emission Ragions
(LINERs) have been selected from the catalogue by Carrillo et al.
(1999). Data on 51 out of the initial 495 optical LINERs are found with
the required signal-to-noise. The X-ray morphology has been classified
attending to their nuclear compactness in the hard band (4.5-8 keV) into
2 categories: AGN-like nuclei (those with a clearly identified
unresolved nuclear source) and Starburst-like nuclei (the ones without a
clear nuclear source). 59% of the total sample are classified as AGNs
with a median luminosity of 2.5x 1040 erg/s, which is an
order of magnitude greather than for SB-like nuclei. The spectral
fitting implies that most of the objects need a non-negligible
contribution from a non-thermal component. Color-Color diagrams are
defined which allow us to compute physical parameters to analyze the
origin of the X-ray emission. This method is specially useful for
galaxies with low S/N for which no spectral fitting can be performed.
The presence of an AGN seems to be the most natural explanation for the
origin of the power-law component. A comparative sample of Seyfert 2
objects has been compiled from Chandra archive, to look for common
properties or eventual differences between both AGN populations.