Bibcode
Hernández-García, L.; González-Martín, O.; Masegosa, J.; Márquez, I.
Bibliographical reference
Highlights of Spanish Astrophysics VIII, Proceedings of the XI Scientific Meeting of the Spanish Astronomical Society held on September 8-12, 2014, in Teruel, Spain, ISBN 978-84-606-8760-3. A. J. Cenarro, F. Figueras, C. Hernández-Monteagudo, J. Trujillo Bueno, and L. Valdivielso (eds.), p. 228-233
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5
2015
Citations
0
Refereed citations
0
Description
Although variability is a general property of AGN, and in LINERs
variations in timescales of months/years have been found for some
objects, it is not clear how these changes occur. The main purpose of
this work is to investigate the X-ray variability in LINERs, including
the main driver of such variations. We use the 18 LINERs in the Palomar
sample with data at different epochs available in Chandra and/or
XMM-Newton archives. All the spectra for the same object are
simultaneously fitted to study long term variations. The nature of the
variability pattern was studied allowing the different parameters to
vary during the spectral fit. Whenever possible, short term variations
and UV variability are studied. Short term variations are not found at
X-rays. Taking into account the data at X-rays (seven out of 12 objects)
and UV (five out of six), ten out of 13 LINERs show long term
variations. The main driver of the X-ray variations is related to
changes in the nuclear power, while changes on absorptions are found
only in one case. According to their BH masses, accretion rates and
variability timescales, LINERs behave as more powerful AGN at X-rays.
However, we conclude that a different accretion mechanism (compared to
more powerful AGN) may be present, based on the anticorrelation between
Γ and the Eddington ratio.