SPACE AND COSMIC RAY PHYSICS SEMINAR

University of Maryland
Atlantic Building, Room 2400
4:30 PM Monday, November 20, 2017
Coffee, Tea & Snacks 4:15-4:30 PM

Elizabeth Hays
NASA Goddard Space Flight Center

High-energy gamma rays from particle accelerators in the Galaxy

Gamma rays have been pursued for a long time as a probe of sources that accelerate cosmic rays. Often, measurements of the shape of the gamma-ray spectrum of sources have been pursued as evidence of sites of hadronic acceleration and the relative contribution of various mechanisms. In this seminar I will talk about several types of time-domain gamma-ray observations that are pushing the understanding of mechanisms at work in Galactic accelerators. The extremely rapid variability of the gamma-ray flares from the Crab Nebula, extending to energies that defy the synchrotron cutoff energy, have motivated fresh looks at particle acceleration in pulsar wind nebulae. The detection of gamma rays from Galactic novae is another case where information about time development in gamma rays and at other wavelengths provides new insight into where and how acceleration occurs. We can use these examples to think about the ways that future observations may inform our understanding of Galactic particle accelerators.