Speaker
Description
There is compelling observational evidence that an emerging group of
compact radio galaxies, which lack of extended radio emission,
dominate in number the radio-loud AGN population in the local Universe. We call
these sources 'FR0' in opposition to the other Fanaroff-Riley classes
to emphasize their lack of prominent extended radio emission. They
are compact on a scale of < 5 kpc, within the host galaxy. Their host
and nuclear properties are indistinguishable from the FRI radio
galaxies, but more abundant and with smaller jets than classical
FRIs. I will present high and low-resolution observations down to low
radio frequencies (from EVN, eMERLIN, VLA, LOFAR and GMRT) to
reconstruct the radio spectral properties and then the history of this
abundant population. Considering the whole properties of the FR0s, we
speculate their possible origins (young radio sources or more exotic
nature) and the possible cosmological scenarios they imply.
