The problem of low-energy positron production in the Galaxy and subsequent annihilation of these positrons into gamma rays have produced many different hypotheses on the sources. The high intensity of gamma-ray emission sets certain limitations on the properties of these sources. In this review, we provide estimations of the contribution of cosmic rays to the production of low-energy positrons responsible for the formation of the 511-keV annihilation line. Despite cosmic rays being unable to provide a sufficient positron production rate to explain the annihilation emission of the whole Galaxy, their contribution is not negligible.

Keywords: positrons, gamma photons, protons, nuclei, emission, Galaxy PACS: 13.75.Cs, 13.85.Dz, 96.50.S− (all) DOI: 10.3367/UFNe.2025.06.039942 URL: https://ufn.ru/en/articles/2025/7/c/ 2-s2.0-105013757937 2025PhyU...68..668D Citation: Dremin I M, Chernyshov D O "Low-energy positrons and gamma photons in the Galaxy" Phys. Usp. 68 668–674 (2025) BibTexBibNote ® (generic)BibNote ® (RIS)MedlineRefWorks Received: 25th, April 2025, revised: 2nd, June 2025, accepted: 5th, June 2025 Оригинал: Дрёмин И М, Чернышов Д О «Низкоэнергичные позитроны и гамма-кванты в Галактике» УФН 195 713–720 (2025); DOI: 10.3367/UFNr.2025.06.039942