The Hadronic Picture of the Radiogalaxy M87
  Very high energy gamma-ray emission of Fanaroff-Riley I objects is not
univocally explained by a single emission model. Leptonic models with one and
multi-zone emission regions, occurring in the jet of these objects, are usually
used to describe the broadband spectral energy distribution. A correlation
between the X-ray and TeV emission is naturally expected within leptonic models
whereas a lack of correlation between these two observables represents a
challenge and favors the hadronic scenarios. This is the case of M87 as we show
here by analyzing its TeV and X-ray emission recorded in the last decade.
Furthermore, we point out that the spectra obtained by MAGIC, H.E.S.S. and
VERITAS telescopes cannot be described with the same leptonic model introduced
by the Fermi-LAT collaboration. We introduce hadronic scenarios to explain the
TeV gamma-ray fluxes of this radiogalaxy as products of Fermi-accelarated
protons interacting with seed photons in the jet or thermal particles in the
giant lobes. By fitting this part of spectral energy distribution as pion decay
products, we obtain the expected neutrino counterpart and the luminosity of
accelerating protons in the jet and/or lobes. With the expected neutrino fluxes
we investigate, through Monte Carlo simulations, the possibility to see the
signal from M87 with a Km$^{3}$ neutrino telescope, and compare the results
with what has been seen by IceCube experiment up to now. Finally we constrain
the features of giant lobes through the observations performed at ultra high
energies by TA experiment.
