Abstract
We present studies of the massive protocluster AFGL 5142 in the J = 2-1 transition of the CO isotopologues, SO, CH 3 OH, and CH 3 CN lines, as well as in the continuum at 225 GHz and 8.4 GHz. The 225 GHz continuum emission reveals at least five dust continuum peaks. The strongest peaks, MM-1 and MM-2, are associated with hot cores with temperatures of 90 ± 20 and 250 ± 40 K, respectively. With similar core mass, the higher temperature and CH 3 CN abundance in the MM-2 core suggest that it might be at a more evolved stage than the MM-1 core. A total of 22 lines from nine molecules are detected. The line strength varies remarkably in the region. Strong SO emission is found both in molecular outflows and cloud cores. CH 3 OH emission, on the contrary, is much weaker in molecular outflows, and is detected toward hot cores MM-1 and MM-2, but is absent in the less massive and perhaps less evolved cores MM-3, MM-4, and MM-5. The CO and SO emission reveals at least three molecular outflows originating from the center of the dust core. The outflows are well collimated, with terminal velocities up to 50 km s -1 from the cloud velocity. Since jetlike outflows and disk-mediated accretion process are physically connected, the well-collimated outflows indicate that even in this cluster environment, accretion is responsible for the formation of individual stars in the cluster. © 2007. The American Astronomical Society. All rights reserved.