I work in the field of particle astrophysics, an interdisciplinary area on the boundaries of high energy astrophysics and traditional particle physics.  I am interested in studying the behavior of matter and energy in some of the most extreme environments in the universe: for example, near the supermassive black holes at the centers of active galactic nuclei, in the fireballs produced when gamma ray bursts explode, and in the relativistic shock waves emitted by galactic supernovae. 

Charged particles known as cosmic rays are accelerated in these sites in a manner not fully understood, and studying the charged particles, photons, and neutrinos emitted from these objects should shed light on the physical processes that take place in environments not replicable on Earth.  In addition, many of the particles emitted by these objects travel cosmological distances to reach us, permitting us to study the nature of the particles themselves and the early Universe through which they travel in novel ways.  The detectors we build can also be used to search for exotic forms of matter theorized to exist but not yet observed in the laboratory: dark matter, supersymmetric matter, and other particles beyond the Standard Model of particle physics.

My research efforts are currently focused on the IceCube Neutrino Observatory at the South Pole, the world’s largest detector of subatomic particles called neutrinos.  IceCube has detected several dozen neutrinos from sources outside our Solar System, and we are working hard to understand where they came from.  IceCube also detects almost 100,000 neutrinos produced in our atmosphere every year – one of the world’s largest neutrino data sets.  The MSU research group uses this data to observe how neutrinos oscillate between different flavors, which tells us about the neutrinos’ fundamental properties.  The neutrinos observed by IceCube are over an order of magnitude more energetic than those detected by other neutrino experiments, so combining our results with those of other experiments is a way to search for unexpected phenomena related to neutrinos.  We can also make several unique measurements, including high-statistics observations of tau neutrino appearance, searches for oscillations into a fourth, “sterile” type of neutrino triggered by neutrinos’ passage through the Earth, and measurements of neutrino interaction rates at very high energies.

In addition to IceCube, I participate in the High Altitude Water Cherenkov (HAWC) TeV gamma ray observatory at Volcán Sierra Negra, México.  Like IceCube, HAWC searches for sites of high energy particle acceleration in our Galaxy and throughout the universe.