1996A&AS..120C.349H

Intense γ-ray line emission at 4.44 and 6.13MeV from the nuclear deexcitation of ¹²C^*4.44 and ¹⁶O^*6.13 has recently been discovered (Bloemen et al. 1994A&A...281L...5B) by the COMPTEL experiment from the Orion complex, a nearby (∼450pc) molecular cloud with a resident association of massive OB stars. This emission is apparently produced by low energy (<30MeV/nucleon) cosmic rays, which are accelerated by shocks and undergo nuclear interactions with the dense cloud gas. To test this hypothesis, we have identified several similar candidate OB associations from which we would also expect comparable fluxes in these two nuclear γ-ray lines.