The new class of FR0 radio galaxies
  Are the FRI and FRII radio galaxies representative of the radio-loud (RL) AGN
population in the local Universe? Recent studies on the local low-luminosity
radio sources cast lights on an emerging population of compact radio galaxies
which lack extended radio emission. In a pilot JVLA project, we study the
high-resolution images of a small but representative sample of this population.
The radio maps reveal compact unresolved or slightly resolved radio structures
on a scale of 1-3 kpc. We find that these RL AGN live in red massive early-type
galaxies, with large black hole masses ($\gtrsim$10$^{8}$ M$_{\odot}$), and
spectroscopically classified as Low Excitation Galaxies, all characteristics
typical of FRI radio galaxies which they also share the same nuclear luminosity
with. However, they are more core dominated (by a factor of $\sim$30) than FRIs
and show a clear deficit of extended radio emission. We call these sources
'FR0' to emphasize their lack of prominent extended radio emission. A
posteriori, other compact radio sources found in the literature fulfill the
requirements for a FR0 classification. Hence, the emerging FR0 population
appears to be the dominant radio class of the local Universe. Considering their
properties we speculate on their possible origins and the possible cosmological
scenarios they imply.
