An image of Bert, one of a few dozen high-confidence astrophysical neutrinos detected by IceCube. The dots are each a location of a sensor in IceCube, with the colors denoting the time the sensor saw light and the size denoting how much light was seen. In this event, the light propagates outward from the point of the neutrino interaction.

The IceCube observatory is an instrument for detecting and mapping high-energy neutrinos. The detector is built in the deep ice under the South Pole. It was built incrementally between 2004-2011. Sensors were deployed in holes throughout a cubic kilometer. When high-energy neutrinos interact in the detector, they can produce particles or showers of light detectable by the sensors.

One of the main science objectives is to study the origin of cosmic radiation. Cosmic rays consist of mostly protons and helium (with some rare heavier nuclei) that continuously bombard the Earth. It is currently unclear exactly where cosmic rays are produced but, because of the mechanics of cosmic ray interactions, we expect the sites of cosmic ray accelration to also be bright in neutrinos. Prior to IceCube, however, these neutrinos had never been detected.

For the first time, in 2013, the IceCube collaboration announced discovery of a population of astrophysical neutrinos being produced outside the Earth. It is likely that these events are byproducts of cosmic-ray acceleration out in the cosmos. The data, however, does not currently show any clustering on the sky. It is currently unclear, therefore, exactly what sources may be producing the neutrinos.

While IceCube continues to take data, hoping to identify "bumps" in their data from identifiable sources, we can follow up their events looking for the gamma rays that may accompany the neutrino events. Since writing my thesis using early IceCube data in 2006, I have been working on this gamma-ray followup with HAWC