Observations of very-high-energy ( VHE , E > 250 GeV ) \gamma -ray emission from several blazars at z > 0.1 have placed stringent constraints on the elusive spectrum and intensity of the intergalactic infrared background radiation ( IIBR ) .
Correcting their observed VHE spectrum for \gamma \gamma absorption even by the lowest plausible level of the IIBR provided evidence for a very hard ( photon spectral index \Gamma _ { ph } < 2 ) intrinsic source spectrum out to TeV energies .
Such a hard VHE \gamma -ray spectrum poses a serious challenge to the conventional synchrotron-self-Compton interpretation of the VHE emission of TeV blazars and suggests the emergence of a separate emission component beyond a few hundred GeV .
Here we propose that such a very hard , slowly variable VHE emission component in TeV blazars may be produced via Compton upscattering of Cosmic Microwave Background ( CMB ) photons by shock-accelerated electrons in an extended jet .
For the case of 1ES 1101-232 , this component could dominate the bolometric luminosity of the extended jet if the magnetic fields are of the order of typical intergalactic magnetic fields ( B \sim 10 \mu G ) and electrons are still being accelerated out to TeV energies ( \gamma \gtrsim 4 \times 10 ^ { 6 } ) on kiloparsec scales along the jet .