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We use deep multi-colour (UBVRIJK) images mostly taken in the framework of the ESO Deep Public Survey (DPS) to optically identify and derive photometric redshifts for a complete sample of 131 radio sources with S>0.4 mJy, observed at both 1.4 and 5 GHz as part of the ATESP radio survey. The availability of multi-wavelength radio and optical information is exploited to infer the physical properties of the faint radio population. In particular we find that, considering both early-type galaxies and quasars as sources with an active nucleus, AGNs largely dominate our sample sub-mJy sample (78%). Further radio/optical analysis of such AGN component has revealed a somewhat unexpected class of flat/inverted-spectrum sources with low radio-to-optical ratios (R<100), which are preferentially identified with early-type galaxies. Such sources are quite compact (d<10-30 kpc), suggesting core-dominated radio emission triggered by low luminosity AGNs. This intriguing class of objects deserves further analysis, and new higher resolution radio observations are currently under way. In parallel we are developing radio source models, for both the AGN and the star-forming components of the sub-mJy radio pupulation. Here we discuss the first results.
The up-turn in Euclidean normalised source counts below 1mJy at 1.4GHz is well established in many deep radio surveys. There are strong reasons, observationally and theoretically, to believe that this up-turn is due to strong evolution of the starfor
Deep surveys in the far-infrared and sub-millimeter wavebands are revealing a new phase of galactic evolution hidden by dust. Observations with SCUBA on the JCMT show that 25% of the COBE/FIRAS background at 850 microns is being produced by high lumi
We present new near-IR and optical spectroscopic observations which confirm the redshift of the z=1.44 extremely red object ERO J164502+4626.4 (object 10 of Hu & Ridgway 1994) and a HST image which reveals a reflected-S-shaped morphology at (rest-fra
We investigate the star formation properties of ~800 sources detected in one of the deepest radio surveys at 1.4 GHz. Our sample spans a wide redshift range (~0.1 - 4) and about four orders of magnitude in star formation rate (SFR). It includes both