Oscar Macias

Dark Matter and Pulsar Model Constraints from Galactic Center Fermi-LAT Gamma Ray Observations

Employing Fermi-LAT gamma ray observations, several independent groups have found excess extended gamma ray emission at the Galactic center (GC). Both, annihilating dark matter (DM) or a population of

Contribution of cosmic rays interacting with molecular clouds to the Galactic Center gamma-ray excess

\sim 10^3

The Fermi-LAT gamma-ray excess at the Galactic Center in the singlet-doublet fermion dark matter model

unresolved millisecond pulsars (MSPs) are regarded as well motivated possible explanations. However, there is significant uncertainties in the diffuse galactic background at the GC. We have performed a revaluation of these two models for the extended gamma ray source at the GC by accounting for the systematic uncertainties of the Galactic diffuse emission model. We also marginalize over point source and diffuse background parameters in the region of interest. We show that the excess emission is significantly more extended than a point source. We find that the DM (or pulsars population) signal is larger than the systematic errors and therefore proceed to determine the sectors of parameter space that provide an acceptable fit to the data. We found that a population of order a 1000 MSPs with parameters consistent with the average spectral shape of Fermi-LAT measured MSPs was able to fit the GC excess emission. For DM, we found that a pure

Galactic bulge preferred over dark matter for the Galactic centre gamma-ray excess

\tau^+\tau^-

Cosmic ray models of the ridge-like excess of gamma rays in the Galactic Centre

annihilation channel is not a good fit to the data. But a mixture of

Consistency between the luminosity function of resolved millisecond pulsars and the galactic center excess

\tau^+\tau^-

Spatial morphology of the secondary emission in the Galactic Center gamma-ray excess

and

Cosmological constraints on dark matter annihilation and decay: Cross-correlation analysis of the extragalactic

b\bar{b}

\gamma

with a

-ray background and cosmic shear

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