Webinar: The Fermi GeV Bulge Emission: Dark Matter Annihilation or Millisecond Pulsars?
por
Christoph Weniger
(University of Amsterdam)
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Europe/Madrid
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Descripción
Gamma-ray observations of the Galactic bulge and center with the Fermi Large Area Telescope (LAT) show an excess of photons at 1-3 GeV energies. This was pointed out by many group since 2009, and recently confirmed by the Fermi LAT collaboration. Interestingly, the emission is compatible with a signal from annihilating dark matter. This generated significant excitement in the WIMP dark matter community, and it makes it urgent to understand the true origin of the emission.
I will summarize our current knowledge about the GeV bulge emission. A leading astrophysical interpretation of the emission is that it comes from thousands of hitherto unknown millisecond pulsars (MSPs) in the Galactic bulge. I will discuss in some detail a wavelet fluctuation analysis of the gamma-ray emission from the inner Galaxy, which we did recently to test this hypothesis. We found strong support for the MSP hypothesis. However, systematic uncertainties remain large, and a clear detection of the bulge MSPs in radio observations will be necessary for a solid confirmation. If as significant number of MSPs is found in the Galactic bulge, this will reduce, and possibly eliminate, the need for more exotic explanations in terms of dark matter annihilation. I will close with our plans to search for these sources in radio, using MeerKAT (planned for 2018) and telescopes like the GBT and the VLA.