Positron excess in the center of the Milky Way from short-lived beta(=) emitting isotopes

摘要

Observations of the INTEGRAL satellite revealed the presence of yet unexplained excess in the central region of the Galaxy at energies around 511 keV. These gamma rays are produced in the process of positron annihilation; the needed rate is around 10(42) s(-1). In this short paper it is shown that beta(+) -emitting isotopes that are formed in interactions of subrelativistic cosmic rays with light nuclei (CNONe) can account for a considerable fraction-up to several tens of percent-of e(+) production rate in the central region.