We used the Australia Telescope Compact Array (ATCA) to follow-up at 5 GHz part of the region previously covered by the sub-mJy ATESP 1.4 GHz survey. We imaged a one-square degree area where extensive UBVRIJKs deep imaging is available through the multicolor ESO Deep Public Survey. The 1.4 and 5 GHz information allowed us to study the radio spectral properties of the ATESP radio sources. We found a significant flattening of the 1.4-5 GHz spectral indices going to fainter flux. Such a flattening is consistent with a flattening for the 5 GHz source counts occuring at fluxes ≤ 0.5 mJy. We then used the optical information available to assess the nature of the ATESP sub-mJy sources and the physical processes responsible for such a flattening. Preliminary results indicate that flat/inverted sources are more probably triggered by nuclear activity than by star formation.
Gregorini L., Prandoni I., Mignano A., Parma P., de Ruiter H.R., Wieringa M.H., et al. (2007). Radio and optical properties of faint radio population. SAN FRANCISCO : Astronomical Society of the Pacific.
Radio and optical properties of faint radio population
GREGORINI, LORETTA;
2007
Abstract
We used the Australia Telescope Compact Array (ATCA) to follow-up at 5 GHz part of the region previously covered by the sub-mJy ATESP 1.4 GHz survey. We imaged a one-square degree area where extensive UBVRIJKs deep imaging is available through the multicolor ESO Deep Public Survey. The 1.4 and 5 GHz information allowed us to study the radio spectral properties of the ATESP radio sources. We found a significant flattening of the 1.4-5 GHz spectral indices going to fainter flux. Such a flattening is consistent with a flattening for the 5 GHz source counts occuring at fluxes ≤ 0.5 mJy. We then used the optical information available to assess the nature of the ATESP sub-mJy sources and the physical processes responsible for such a flattening. Preliminary results indicate that flat/inverted sources are more probably triggered by nuclear activity than by star formation.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
