The possibility of observation of the Lα-line of positronium (e+e−) from astronomical objects

We analyze from a physical point of view the possibility of observation of the Lα-line of the positronium (Ps). In a broad range of temperatures the processes of recombination to states of Ps with different quantum numbers nl and collisions of Ps with electrons and protons are examined. It is shown that the electron density in annihilation sources can be obtained from the intensity of the Lα-line of positronium