Fermi LAT Search for Internal Bremsstrahlung Signatures from Dark Matter Annihilation

Understand

A commonly encountered obstacle in indirect searches for galactic dark matter is how to disentangle possible signals from astrophysical backgrounds.

• Given that such signals are most likely subdominant, the search for pronounced spectral features plays a key role for indirect detection experiments; monochromatic gamma-ray lines or similar features related to internal bremsstrahlung, in particular, provide smoking gun signatures.
• We perform a dedicated search for the latter in the data taken by the Fermi gamma-ray space telescope during its first 43 months.
• To this end, we use a new adaptive procedure to select optimal target regions that takes into account both standard and contracted dark matter profiles.