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Physics Colloquium

Thursday, April 27, 2023
4:00pm to 5:00pm
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Online and In-Person Event
The Galactic Center Gamma-Ray Excess
Daniel Hooper, University of Chicago,

The Galactic Center Gamma-Ray Excess has a spectrum, angular distribution, and overall intensity that agree remarkably well with that expected from annihilating dark matter particles in the form of a ∼ 50 GeV thermal relic. Previous claims that these photons are clustered on small angular scales or trace the distribution of known stellar populations once appeared to favor interpretations in which this signal originates from a large population of unresolved millisecond pulsars. More recent work, however, has overturned these conclusions, finding that the observed gamma-ray excess does not contain discernible small scale power, and is distributed with approximate spherical symmetry, not tracing any known stellar populations. In light of these results, it now appears significantly more likely that the Galactic Center Gamma-Ray Excess is produced by annihilating dark matter.

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Meeting ID: 858 1199 4621

The colloquium is held in Feynman Lecture Hall, 201 E. Bridge.

In person is open to those with a valid Caltech ID.