The GeV Excess Shining Through: Background Systematics for the Inner Galaxy Analysis

Recently, a spatially extended excess of gamma rays collected by the Fermi-LAT from the inner region of the Milky Way has been detected by different groups and with increasingly sophisticated techniques. Yet, any final conclusion about the morphology and spectral properties of such an extended diffuse emission are subject to a number of potentially critical uncertainties, related to the high density of cosmic rays, gas, magnetic fields and abundance of point sources. We will present a thorough study of the systematic uncertainties related to the modelling of diffuse background and to the propagation of cosmic rays in the inner part of our Galaxy. We will test a large set of models for the Galactic diffuse emission, generated by varying the propagation parameters within extreme conditions. By using those models in the analysis of Fermi-LAT data as Galactic foreground, we will show that the gamma-ray excess survives and we will quantify the uncertainties affecting the excess morphology and energy spectrum.Comment: 2014 Fermi Symposium proceedings - eConf C14102.1 7 pages, 4 figure

Searching for the continuum spectrum photons correlated to the 130 GeV gamma-ray line

Indications for a gamma-ray line(s) signal towards the Galactic center at an energy of about 130 GeV have been recently presented. While dark matter annihilations are a viable candidate for this signal, it is generally expected that such a flux would be correlated to a gamma-ray component with continuum energy spectrum due to dark matter pair annihilating into other Standard Model particles. We use the gamma-ray data from the inner 10 x 10 degree window to derive limits for a variety of DM annihilation final states. Extending the window of observation, we discuss bounds on the morphological shape of a dark matter signal associated to the line, applying both standard templates for the dark matter profile, such as an Einasto or a NFW profile, and introducing a new more general parametrization.Comment: 9 pages, 6 figures and 1 table, corrected typographical errors, added citations and journal referenc