Probing the Extragalactic Background Light
with TeV Photons
Frank Krennrich
Iowa State University
Ground-based gamma-ray observatories such as H.E.S.S., MAGIC and
VERITAS have given us a glimpse of particle accelerators in our
Universe that are "visible" in TeV photons. A wealth of
astrophysical non-thermal phenomena has been revealed through the
detection of a variety of galactic and extragalactic TeV sources
(~ 80). The scientific interest in these evolves around today?s big
questions in astrophysics and particle physics.
In this talk, I will focus on the very bright TeV beams from jets of
active galaxies that allow us to probe the intervening primordial
radiation fields, namely the Extragalactic Background Light (EBL), by
gamma-ray absorption via pair production. The EBL contains important
information about the star and galaxy formation history of the
universe and is also sensitive to cosmological defects and the
evaporation of black holes. I will discuss the energy dependent
transparency of the universe in gamma rays, recent developments and
implications. Finally, I will give an outlook for future observations
with next generation TeV telescopes such as AGIS and CTA.
Astrophysics Seminar
Markus Böttcher's home page
OU Astronomy and Astrophysics
Department Physics and Astronomy
Ohio University