Extensive X-ray variability studies of NGC 7314 using long XMM-Newton
  observations
  We present a detailed X-ray variability study of the low mass Active Galactic
Nuclei (AGN) NGC 7314 using the two newly obtained XMM-Newton observations
($140$ and $130$ ks), together with two archival data sets of shorter duration
($45$ and $84$ ks). The relationship between the X-ray variability
characteristics and other physical source properties (such as the black hole
mass) are still relatively poorly defined, especially for low-mass AGN. We
perform a new, fully analytical, power spectral density (PSD) model analysis
method, which will be described in detail in a forthcoming paper, that takes
into consideration the spectral distortions, caused by red-noise leak. We find
that the PSD in the $0.5-10$ keV energy range, can be represented by a bending
power-law with a bend around $6.7\times10^{-5}$ Hz, having a slope of $0.51$
and $1.99$ below and above the bend, respectively. Adding our bend time-scale
estimate, to an already published ensemble of estimates from several AGN,
supports the idea that the bend time-scale depends linearly only on the black
hole mass and not on the bolometric luminosity. Moreover, we find that as the
energy range increases, the PSD normalization increases and there is a hint
that simultaneously the high frequency slope becomes steeper. Finally, the
X-ray time-lag spectrum of NGC 7314 shows some very weak signatures of
relativistic reflection, and the energy resolved time-lag spectrum, for
frequencies around $3\times10^{-4}$ Hz, shows no signatures of X-ray
reverberation. We show that the previous claim about ks time-delays in this
source, is simply an artefact induced by the minuscule number of points
entering during the time-lag estimation in the low frequency part of the
time-lag spectrum (i.e. below $10^{-4}$ Hz).
