School of Physics Colloquium Series: Prof. Stefan Westerhoff, Wisconsin IceCube Particle Astrophysics Center (WIPAC)

In March 2015, Mexico and the U.S. inaugurated a new high-energy gamma-ray observatory near Puebla, Mexico: the HAWC (High-Altitude Water Cherenkov) Observatory. Located at 4,100 meters altitude, HAWC is a large field-of-view instrument capable of continuously monitoring the northern sky at energies between 100 GeV and 100 TeV, the highest gamma-ray energies observed so far.

Over the next decade, HAWC data will be used to study some of the most violent objects in the known Universe, from supermassive black holes to the remnants of supernova explosions, and provide an unbiased survey of the high-energy sky. Since the Earth's atmosphere is opaque to gamma rays at TeV energies, HAWC is a rather unusual astronomical instrument. It comprises 300 large light-tight water tanks covering an area of 20,000 square meters. Each tank is instrumented with four photomultipliers to detect particles from extensive air showers produced by gamma rays and cosmic rays upon entering the Earth's atmosphere.

I will present the HAWC science case and the detector principle and discuss first results based on data taken since 2013 with the partially deployed detector.