We present a series of X-ray variability results from a long XMM-Newton +
NuSTAR campaign on the bright, variable AGN NGC 3227. We present an analysis of
the lightcurves, showing that the source displays typically
softer-when-brighter behaviour, although also undergoes significant spectral
hardening during one observation which we interpret as due to an occultation
event by a cloud of absorbing gas. We spectrally decompose the data and show
that the bulk of the variability is continuum-driven and, through rms
variability analysis, strongly enhanced in the soft band. We show that the
source largely conforms to linear rms-flux behaviour and we compute X-ray power
spectra, detecting moderate evidence for a bend in the power spectrum,
consistent with existing scaling relations. Additionally, we compute X-ray
Fourier time lags using both the XMM-Newton and - through maximum-likelihood
methods - NuSTAR data, revealing a strong low-frequency hard lag and evidence
for a soft lag at higher frequencies, which we discuss in terms of
reverberation models.Comment: Accepted for publication in MNRAS; 19 pages, 13 figures, 4 tables;
minor typographical errors corrected and reference list update
