Research Projects
My most recent project involves working on gamma-ray pulsars, using Fermi-LAT data. In particular, I work on blind searches of LAT gamma-ray data. Prior to our work, no pulsar had ever been discovered in gamma rays, and only 6 pulsars were known to have GeV emission. We have now discovered 16 new pulsars with the LAT and an additional 30 radio pulsars have been shown to emit gamma rays, including 8 milli-second pulsars. Our work was recently featured in the 14 August 2009 cover issue of Science. You can download our article on the discovery of the first 16 pulsars in blind searches of LAT data here.
As part of the Milagro collaboration, I also work on the Very High Energy (> 100 GeV) part of the spectrum. We recently analyzed 8 years of Milagro data looking for VHE emission from the brightest Fermi sources (mainly pulsars). Here is our most recent paper on this topic.
I have also been heavily involved in the search for Very High Energy (> 100 GeV) emission from GRBs, using Milagro. One of the strengths of an all-sky instrument such as Milagro is that it has a very large field of view and duty cycle (much like Fermi), which allows for continuous observations of the northern hemisphere sky. Unfortunately, there have been no conclusive detections of emission in the Milagro energy range (100 GeV - 100 TeV), but in this paper, for instance, we placed the strongest constraints on the prompt VHE emission from short gamma-ray bursts (those lasting only a few seconds).