THIS PROPOSAL OUTLINES A MEANS TO INVESTIGATE THE ORIGIN OF ULTRA-HIGH-ENERGY COSMIC RAYS (UHECRS; E1 PEV) THE DENSITY AND EVOLUTION OF THE EXTRAGALACTIC BACKGROUND LIGHT AND EVIDENCE FOR EXOTIC AXION-LIKE PARTICLES IS POSSIBLE THROUGH THE COMBINATION OF DEEP FERMI LAT AND VERITAS OBSERVATIONS OF SEVEN MODERATE-OPACITY-PROBING VERY-HIGH-ENERGY (VHE; E>100 GEV) BLAZARS. PUZZLING YET SIGNIFICANT EVIDENCE FOR SPECTRAL HARDENING AT THE HIGHEST ENERGIES HAS NOW BEEN OBSERVED WITH MULTIPLE VHE INSTRUMENTS FOR MULTIPLE BLAZARS. THESE OBSERVATIONS SUPPORT THE NEED FOR AN ADDITIONAL COMPONENT TO BE INCLUDED IN THE EMISSION MODELS WHICH CAN CLEARLY BE INVESTIGATED THROUGH THE MERGING OF LAT AND VERITAS OBSERVATIONS FOR MODERATE-OPACITY-PROBING BLAZARS SUCH AS THE SEVEN TARGETED BY THIS PROPOSAL. THE COMBINATION OF FERMI LAT AND VERITAS BLAZAR OBSERVATIONS WILL ALLOW A CLEAR VIEW OF THEINTRINSIC EMISSION AND THE SEARCH FOR A GLOBAL OPACITY-SPECIFIC SPECTRAL HARDENING.

California State University, East Bay Foundation, Inc., Hayward CA

Investigators