We present mapping observations of molecular lines 12CO (2-1), 12CO (3-2), 13CO (2-1), and 13CO (3-2) toward the massive star-forming region IRAS 04000+5052 that suggest kinematics consistent with cloud-cloud collision and a possible unusual abundance ratio of carbon isotopes. Together with the previous spectroscopic study that shows an extreme deficiency in heavy elements in the surrounding nebulosity - suggestive of primordial nature - we propose that the cloud material is of intergalactic origin and that the young star cluster in IRAS 04000+5052 is the consequence of triggered star formation due to the collision of a Galactic cloud with accreted intergalactic material.
- Intergalactic medium
- ISM: abundances
- ISM: clouds
- Online material: color figures
- Stars: formation