Bibcode
Masegosa, J.; Hernández-García, Lorena; Márquez, Isabel; González-Martín, O.
Bibliographical reference
Multiwavelength AGN Surveys and Studies, Proceedings of the International Astronomical Union, IAU Symposium, Volume 304, pp. 399-402
Advertised on:
7
2014
Citations
0
Refereed citations
0
Description
One of the most important features in active galactic nuclei (AGN) is
the variability of their emission. Variability has been discovered at
X-ray, UV, and radio frequencies on time scales from hours to years.
Among the AGN family and according to theoretical studies,
Low-Ionization Nuclear Emission Line Region (LINER) nuclei would be
variable objects on long time scales. Our purpose is to investigate
spectral X-ray variability in LINERs and to understand the nature of
these kinds of objects, as well as their accretion mechanism. Chandra
and XMM-Newton public archives were used to compile X-ray spectra of
LINER nuclei at different epochs with time scales of years. To search
for variability we fit all the spectra from the same object with a set
of models, in order to identify the parameters responsible for the
variability pattern. We found that long term spectral variability is
very common, with variations mostly related to hard energies (2-10 keV).
These variations are due to changes in the soft excess, and/or changes
in the absorber, and/or intrinsic variations of the source.