Are both BL Lacs and pulsar wind nebulae the astrophysical counterparts
  of IceCube neutrino events?
  IceCube has recently reported the discovery of high-energy neutrinos of
astrophysical origin, opening up the PeV (10^15 eV) sky. Because of their large
positional uncertainties, these events have not yet been associated to any
astrophysical source. We have found plausible astronomical counterparts in the
GeV -- TeV bands by looking for sources in the available large area high-energy
gamma-ray catalogues within the error circles of the IceCube events. We then
built the spectral energy distribution of these sources and compared it with
the energy and flux of the corresponding neutrino. Likely counterparts include
mostly BL Lacs and two Galactic pulsar wind nebulae. On the one hand many
objects, including the starburst galaxy NGC 253 and Centaurus A, despite being
spatially coincident with neutrino events, are too weak to be reconciled with
the neutrino flux. On the other hand, various GeV powerful objects cannot be
assessed as possible counterparts due to their lack of TeV data. The definitive
association between high-energy astrophysical neutrinos and our candidates will
be significantly helped by new TeV observations but will be confirmed or
disproved only by further IceCube data. Either way, this will have momentous
implications for blazar jets, high-energy astrophysics, and cosmic-ray and
neutrino astronomy.
