TeV blazars and their distance
  Recently, a new method to constrain the distance of blazars with unknown
redshift using combined observations in the GeV and TeV regimes has been
developed, with the underlying assumption that the Very High Energy (VHE)
spectrum corrected for the absorption of TeV photons by the Extragalactic
Background Light (EBL) via photon-photon interaction should still be softer
than the gamma-ray spectrum observed by Fermi/LAT. The constraints found are
related to the real redshifts by a simple linear relation, that has been used
to infer the unknown distance of blazars. The sample will be revised with the
up-to-date spectra in both TeV and GeV bands, the method tested with the more
recent EBL models and finally applied to the unknown distance blazars detected
at VHE.
