Institute for Advanced Study Informal Astrophysics Seminar

ABSTRACT: Observations of the gamma-ray sky by the Fermi Gamma-ray Space Telescope have revealed a striking sharp-edged, double-lobed structure in 1-100 GeV gamma rays, centered on the Galactic Center and extending 50 degrees north and south of the Galactic plane. The gamma-rays associated with these `Fermi bubbles' have a significantly harder spectrum than emission spatially correlated with maps of the SFD dust and radio synchrotron, or with the diffuse model provided by the Fermi collaboration. Possibly associated signals can be seen in microwaves (associated with the WMAP Haze) and 1.5-2 keV X-rays. I will describe the methods used to identify and analyze the bubbles, characterize their spectrum and some aspects of their morphology, discuss their relation to the Fermi and WMAP Hazes and the implications for dark matter searches, and outline some possible interpretations -- including a Galactic wind or AGN activity -- and the challenges involved in explaining all aspects of the signal.