One of the greatest challenges associated with modeling the formation history of the Universe is the general lack of knowledge regarding the nature of Dark Matter. The existence of astrophysical non-baryonic matter has been established by gravitational effects that can be seen on various scales, including star orbital velocities and galaxy-galaxy collisions. Indirect dark matter searches with ground based gamma-ray observatories provide an alternative for identifying the particle nature of dark matter that is complementary to that of direct searches or accelerator production experiments, such as the Large Hadron Collider (LHC).
VERITAS is a major ground-based gamma-ray observatory located at the basecamp of the Fred Lawrence Whipple Observatory in southern Arizona. VERITAS is composed of an array of four 12-meter optical reflectors for gamma-ray astronomy in the very high energy (50 GeV - 50 TeV) range. These imaging Cherenkov telescopes are deployed such that they have the highest sensitivity in the VHE energy band (50 GeV - 50 TeV), with maximum sensitivity from 100 GeV to 10 TeV. This VHE observatory effectively complements the NASA Fermi mission.
The best laboratory for constraining the nature of the dark matter particles is through observations of nearby dwarf spheroidal galaxies, which are dark-matter-dominated objects which have well-measured dark matter density profiles (through stellar velocity measurements). VERITAS focuses on the indirect search for very-high-energy gamma rays through observation of these dwarf galaxies which would result from the interaction or decay of Dark Matter particles, as determined by certain Dark Matter models.
The Argonne TeV Gamma-Ray group are members of the VERITAS Dark Matter and Fundamental Science Working group. The group developed, in collaboration with Iowa State University, a new Level 2 trigger for the VERITAS upgrade in 2010-2012. The group has also been involved in developing a new Schwarzschild-Couder telescope design for the next generation of VHE gamma-ray experiments.
- DOE, NSF, SAO