Physics & Astronomy
Colloquium
I will give a broad overview of the field of high energy astrophysics,
particularly emphasizing gamma-ray astronomy. Relativity is critical
for this field. For example, cosmic ray particle energies reach 1010
times their rest mass energies. General relativistic effects are also
important when one deals with compact objects such as neutron stars
and black holes.
The observational side of the field has been greatly advanced in the
past decade by the advent of the Chandra imaging X-ray Observatory
sensitive to photons in the range 0.5 to 10 keV and by operation of
the Gamma Ray Observatory satellite with instruments sensitive to
photons from 50 keV to 10 GeV. I will particularly emphasize its
discoveries, which include the phenomenology of gamma-ray bursts,
gamma-ray pulsars, and jets of active galactic nuclei capable of
generating photons to 10 GeV and beyond. For some of the latter
classes of objects photons in the TeV range are detected by
ground-based instruments. I will discuss several of the many
unanswered questions of this field, viz. the origin of the highest
energy cosmic rays, the cause(s) of gamma-ray bursts and the nature of
the unidentified galactic gamma-ray sources.
3:30 PM, Friday, January 27, 2006
Room 155, Chem-Phys Building
Dr. Richard C. Lamb
Department of Physics and Astronomy, Iowa State University (Emeritus Professor)
Department of Physics and Astronomy
University of Kentucky
``High Energy Astrophysics''
Refreshments will be served in CP 155 at 3:15 PM