1997A&A...327.1185R

We have studied the complex of small globules discovered by A.D. Thackeray in the southern HII region IC 2944. They are located precisely on the line-of-sight to the luminous OB stars in the region, and thus appear as shadows against the bright HII region. Thanks to this geometry, exceptionally fine details can be discerned on CCD images, which show that the globules are generally sharp-edged and highly structured, and that the complex contains a multitude of fragments in all sizes down to the resolution element of about one arcsec (1800AU). CO millimeter observations reveal that the largest globule consists of two kinematically separate entities, with masses of about 11 and 4M_☉. Very large velocity differences exist between the various globules, suggesting that the globules comprise a highly dynamic system perhaps one million years old. We believe that the globules are the remnants of an elephant-trunk observed from behind, originating as a Rayleigh-Taylor instability in an expanding neutral shell powered by the hot HII region. The globule complex is now in an advanced stage of disintegration. We have found no evidence for star formation in any of the globules.