Long-term monitoring of the archetype Seyfert galaxy MCG-6-30-15: X-ray, optical and near-IR variability of the corona, disc and torus
Author
dc.contributor.author
Lira Teillery, Paulina
Author
dc.contributor.author
Arevalo, P.
Author
dc.contributor.author
Uttley, P.
Author
dc.contributor.author
McHardy, I.
Author
dc.contributor.author
Videla, L.
Admission date
dc.date.accessioned
2015-11-11T14:11:00Z
Available date
dc.date.available
2015-11-11T14:11:00Z
Publication date
dc.date.issued
2015
Cita de ítem
dc.identifier.citation
MNRAS 454, 368–379 (2015)
en_US
Identifier
dc.identifier.other
doi:10.1093/mnras/stv1945
Identifier
dc.identifier.uri
https://repositorio.uchile.cl/handle/2250/135007
General note
dc.description
Artículo de publicación ISI
en_US
Abstract
dc.description.abstract
We present long-term monitoring of MCG-6-30-15 in X-rays, optical and near-IR wavelengths,
collected over 5 yr of monitoring. We determine the power spectrum density of all the observed
bands and show that after taking into account the host contamination similar power is observed
in the optical and near-IR bands. There is evidence for a correlation between the light curves
of the X-ray photon flux and the optical B band, but it is not possible to determine a lag with
certainty, with the most likely value being around 0 d. Strong correlation is seen between
the optical and near-IR bands. Cross-correlation analysis shows some complex probability
distributions and lags that range from 10 to 20 d, with the near-IR following the optical
variations. Filtering the light curves in frequency space shows that the strongest correlations are
those corresponding to the shortest time-scales. We discuss the nature of the X-ray variability
and conclude that this is intrinsic and cannot be accounted for by absorption episodes due to
material intervening in the line of sight. It is also found that the lags agree with the relation
τ ∝ λ4/3, as expected for an optically thick geometrically thin accretion disc, although for a
larger disc than that predicted by the estimated black hole mass and accretion rate in MCG-6-
30-15. The cross-correlation analysis suggests that the torus is located at ∼20 light-days from
the central source and at most at ∼50 light-days from the central region. This implies an active
galactic nucleus bolometric luminosity of ∼3 × 1043 erg s−1 cm−2.