Search for Gamma-Ray Emission from Local Primordial Black Holes with the Fermi Large Area Telescope

Understand

Black holes with masses below approximately $10^{15}$ g are expected to emit gamma rays with energies above a few tens of MeV, which can be detected by the Fermi Large Area Telescope (LAT).

• Although black holes with these masses cannot be formed as a result of stellar evolution, they may have formed in the early Universe and are therefore called Primordial Black Holes (PBHs).
• Previous searches for PBHs have focused on either short timescale bursts or the contribution of PBHs to the isotropic gamma-ray emission.
• We show that, in case of individual PBHs, the Fermi LAT is most sensitive to PBHs with temperatures above approximately 16 GeV and masses $6\times 10^{11}$ g, which it can detect out to a distance of about 0.03 pc.