"Unraveling the Extragalactic Gamma-ray Sky in the Era of the Fermi Space Telescope and VERITAS" by Luis Reyes
February 16, 2011 - 10:00am
The field of high-energy astrophysics is experiencing a revolution due to recent observations that have revealed a Universe that is surprisingly rich, variable and complex at gamma-ray energies. We employ these new observations to address long-standing science topics including: the inner workings of the Universe's most powerful accelerators; the nature of dark matter; and the total amount of light that has been emitted in the Universe since the first stars were formed. This revolution has come about due to the launch of the Fermi Gamma-ray Space Telescope and the full-fledged operation of a new generation of ground-based instruments like VERITAS, H.E.S.S. and MAGIC. Among the different classes of gamma-ray sources observed by these instruments, some active galactic nuclei (AGN) and Gamma-ray Bursts (GRBs) stand out as the most energetic and variable objects observed at any wavelength. In my talk I will describe how the complementary capabilities of space and ground-based instruments are leading us to a better understanding of AGN and GRBs as high-energy sources, and as a cosmological tool to probe the background radiation known as extragalactic background light (EBL). Finally, I will discuss the important scientific return that next-generation instruments like the Cherenkov Telescope Array (CTA) and the High-Altitude Water Cherenkov (HAWC) experiment would bring to the field of extragalactic gamma-ray astrophysics.