Astrophysical lasers in optical Fe II lines in gas condensations near η Carinae
We report here on the discovery of laser action in the range 0.9-2 μm in several spectral lines of Fe II, which are associated with transitions from "pseudo-metastable" states populated by spontaneous transitions from Lyα pumped Fe II levels. The intense Lyα radiation is formed in the HII region of gas condensations close to the star η Car. The laser transitions form together with spontaneous tran