Oral Presentation

Outflows in a 70-micron dark cloud: An SMA/ALMA study of star formation in SDC24

Author(s): Beth Jones (JBCA, The University of Manchester), Gary Fuller (JBCA, The University of Manchester; UK ARC Node), Alessio Traficante (IAPS-INAF), Adam Avison (JBCA, The University of Manchester; UK ARC Node), Ya-Wen Tang (ASIAA), Patrick Koch (ASIAA)

Presenter: Bethany Jones (Jodrell Bank Centre for Astrophysics, The University of Manchester)

Building a timeline for high-mass star formation requires the study of objects spanning range of evolutionary stages. Amongst the youngest, least evolved and least affected by the feedback from young stars are infrared dark clouds (IRDCs). Nevertheless IRDCs still contain a wide range of physical conditions: both cold ~10K gas and hot circumstellar material around young protostars; dense quiescent regions and gas dominated by shocks and feedback; and regions in which grain surface reactions have created a chemical composition rich in complex organics and deuterated species. To fully characterise this range of environments requires a range of spectral tracers while the clustered nature of these environments drives us to require higher spatial and spectral resolution to separate components on sub-parsec scales both on-sky and along the line of sight. In this talk, I present a new combined SMA and ALMA study of the clump SDC24. This clump has a mass of approx. 2000 Msol in a region of a few parsec in size and is a possible precursor to some of the most extreme high-mass star forming environments observed within infrared dark clouds, such as the OB association forming SDC335. SDC24 is seen in absorption at 70 microns, typically interpreted to mean that the region is starless. The spectral coverage and resolution of these new SMA and ALMA observations allow us to uncover and characterise the surprisingly complex activity within this region. Finally, I present the advances that the wSMA will allow in future studies of these regions.