Clusters of black holes as point-like gamma-ray sources

The possibility of identifying some of Galactic gamma-ray sources as clusters of primordial black holes is discussed. The known scenarios of supermassive black hole formation indicate the multiple formation of lower-mass black holes. Our analysis demonstrates that due to Hawking evaporation the cluster of black holes with masses about 1015 g could be observed as a gamma-ray source. The total mass of typical cluster is ∼10 M⊙. Detailed calculations have been performed on the basis of specific model of primordial black hole formation.