Context : Active galactic nuclei ( AGN ) , powered by accretion onto supermassive black holes ( SMBHs ) , are thought to be scaled up versions of Galactic black hole X-ray binaries ( BH-XRBs ) .
In the past few years evidence of such correspondence include similarities in the broadband shape of the X-ray variability power spectra , with characteristic bend times-scales scaling with mass .

Aims : The aim of this project is to characterize the X-ray temporal properties of a sample of AGN to study the connection among different classes of AGN and their connection with BH-XRBs .

Methods : We have performed a uniform analysis of the power spectrum densities ( PSDs ) of 104 nearby ( z < 0.4 ) AGN using 209 XMM-Newton /pn observations .
These PSDs span \simeq 3 decades in temporal frequencies , ranging from minutes to days .
The PSDs have been estimated in three energy bands : 0.2 - 10 ( total ) , 0.2 - 2 ( soft ) , and 2 - 10 keV ( hard ) .
The sample comprises 61 Type-1 AGN , 21 Type-2 AGN , 15 NLSy1 , and 7 BLLACS .
We have fitted each PSD to two models : ( 1 ) a single power-law model and ( 2 ) a bending power-law model .

Results : Among the entire sample , 72 % show significant variability in at least one of the three bands tested .
A high percentage of low-luminosity AGN do not show any significant variability ( 86 % of LINERs ) .
The PSD of the majority of the variable AGN was well described by a simple power-law with a mean index of \alpha = 2.01 \pm 0.01 .
In 15 sources we found that the bending power law model was preferred with a mean slope of \alpha = 3.08 \pm 0.04 and a mean bend frequency of \langle \nu _ { b } \rangle \simeq 2 \times 10 ^ { -4 } Hz .
Only KUG 1031+398 ( RE J1034+396 ) shows evidence for quasi-periodic oscillations .
The ‘ fundamental plane ’ relating variability timescale , black hole mass , and luminosity is demonstrated using the new X-ray timing results presented here together with a compilation of the previously detected timescales from the literature .

Conclusions : Both quantitative ( i.e .
scaling with BH mass ) and qualitative ( overall PSD shapes ) found in this sample of AGN are in agreement with the expectations for the SMBHs and BH-XRBs being the same phenomenon scaled-up with the size of the BH .
The steep PSD slopes above the high frequency bend bear a closer resemblance to those of the ‘ soft/thermal dominated ’ BH-XRB states than other states .