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We present results from a deep VERITAS exposure of the distant (z=0.89)flat-spectrum radio quasar (FSRQ) 4C +55.17. The high flux, hard index andsteady emission found by Fermi LAT observations make this blazar a promisingvery-high-energy (VHE; E>100 GeV) candidate, offering a possibility to clarifythe location of FSRQ VHE emission. Non-detection supports the hypothesis thatany VHE gamma-rays are produced within and absorbed by the broad-line regionwhile VHE detection would support an emission region outside the broad lineregion and far from the base of the jet. This FSRQ additionally provides thepossible means, by photon-photon pair production, to constrain the currentlyavailable extragalactic background light (EBL) models out to the groundbreakingredshift of z=0.89. The log-parabolic model that is fitted to the LAT photonsallows an extrapolation of the fit up to VHE while accounting for the gamma-rayabsorption by the EBL. The VERITAS upper limit derived from the deep exposureis compared to this extrapolated VHE flux.

VERITAS Results from Deep Exposure on the Distant FSRQ 4C +55.17