Submillimeter array observations of NGC 2264-C: molecular outflows and driving sources

We present 1.3 mm Submillimeter Array (SMA) observations at ∼3 arcsec resolution towards the brightest section of the intermediate/massive star-forming cluster NGC 2264-C. The millimetre continuum emission reveals ten 1.3 mm continuum peaks, of which four are new detections. The observed frequency range includes the known molecular jet/outflow tracer SiO (5−4), thus providing the first high-resolution observations of SiO towards NGC 2264-C. We also detect molecular lines of 12 additional species towards this region, including CH₃CN, CH₃OH, SO, H₂CO, DCN, HC₃N, and ¹²CO. The SiO (5−4) emission reveals the presence of two collimated, high-velocity (up to 30 km s⁻¹ with respect to the systemic velocity) bipolar outflows in NGC 2264-C. In addition, the outflows are traced by emission from ¹²CO, SO, H₂CO, and CH₃OH. We find an evolutionary spread between cores residing in the same parent cloud. The two unambiguous outflows are driven by the brightest mm continuum cores, which are IR-dark, molecular line weak, and likely the youngest cores in the region. Furthermore, towards the Red MSX Source AFGL 989-IRS1, the IR-bright and most evolved source in NGC 2264-C, we observe no molecular outflow emission. A molecular line rich ridge feature, with no obvious directly associated continuum source, lies on the edge of a low-density cavity and may be formed from a wind driven by AFGL 989-IRS1. In addition, 229 GHz class I maser emission is detected towards this feature.