A CO/ and IRAS study of Cometary GLOBULE:12

Observations of the J = 2 - 1 CO and C¹⁸O lines are reported towards the reflection nebula NGC 5367 in the head of Cometary Globule CG 12, which show it to be only the second example known to date of molecular outflow activity in such an object. The CO has a bipolar shape, centred close to the infrared source IRAS 13547-3944. This has a bolometric luminosity ~110 L⊙, and lies close to a 13.5 M⊙ molecular core whose kinetic temperature ~20K and diameter ~0.15 pc. This core appears virialised, and offset from the highest temperature material along the eastern edge of the dense gas - which is probably heated by the UV radiation of a nearby B4 star. A highly collimated (axial ratio ≥5) and low-luminosity molecular outflow originates close to this core, extends over a length of 0.9 pc, and contains ~0.05 M⊙ of outfiowing material. The structure of the outflow is discussed along with its relationship to the rest of the globule. This is an example of a relatively isolated low-intermediate mass star formation region, which is speculated to have formed as the result of a nearby supernova event 10 - 20 million years ago, and has to date converted about 20 percent of its gas mass into stars