2006ApJ...642..330L

We present BIMA and SCUBA observations of the young cluster associated with BD +40 4124 in the dense molecular gas tracer CS J=2⟶1 and the continuum dust emission at λ=3.1 mm and 850 µm. The dense gas and dust in the system are aligned in a long ridge morphology extending ∼0.4 pc with 16 gas clumps of estimated masses ranging from 0.14 to 1.8 M_☉. A north-south variation in the CS center line velocity can be explained with a two-cloud model. We posit that the BD +40 4124 stellar cluster formed from a cloud-cloud collision. The largest line widths occur near V1318 Cyg S, a massive star affecting its natal environment. In contrast, the dense gas near the other, more evolved, massive stars displays no evidence for disruption; the material must either be processed into the star, dissipate, or relax fairly quickly. The more evolved low-mass protostars are more likely to be found near the massive stars. If the majority of low-mass stars are coeval, the seemingly evolved low-mass protostars are not older: the massive stars have eroded their structures. Finally, at the highest resolution, the λ=3.1 mm dust emission is resolved into a flattened structure 3100x1500 AU with an estimated mass of 3.4 M_☉. The continuum and CS emission are offset by 1".1 from the southern binary source. A simple estimate of the extinction due to the continuum emission structure is A_V∼700 mag. From the offset and because the southern source is detected in the optical, the continuum emission is from a previously unknown very young, intermediate-mass, embedded stellar object.