0720016

We propose to perform with INTEGRAL a long monitoring of 10 observations of 200 ks each of the Seyfert 1 galaxy Mkn 509 simultaneously with an already accepted XMM-Newton monitoring (10 pointings of 60 ks each spaced by 4 days) of this source.This will provide for the first time a very broad band spectral follow-up from the UV to the soft $gamma$-ray of a Seyfert galaxy on a month time scale. This will permit: 1) to disentangle the different spectral components in the UV soft X medium X-ray and $gamma$-ray bands 2) to test different origin of the primary continuum by determining whether the shape of the X-ray continuum is related to the UV intensity 3) to elucidate the origin of the soft X-ray excess and 4) to determine the shape and variability of the Fe 6-7 KeV emission complex and it relation to the high energy ($>$ 10 keV) band. The proposed simultaneous INTEGRAL/XMM-Newton long monitoring of one of the brightest Seyfert galaxies is a unique opportunity to put firm conclusionson the still largely unknown nature and origin of the UV/X-ray/$gamma$-ray emission of this class of objects. [truncated! Please see actual data for full text]