Protostars and Planets VI, Heidelberg, July 15-20, 2013

Poster 1B001

The JCMT dense gas survey in dense molecular clouds: an HCO+/HCN comparison

Walker-Smith, Samantha (Cavendish Laboratory, University of Cambridge)
Richer, John (Cavendish Laboratory, University of Cambridge)
Buckle, Jane (Cavendish Laboratory, University of Cambridge)
Salji, Carl (Cavendish Laboratory, University of Cambridge)
Hatchell, Jennifer (School of Physics, University of Exeter)
Drabek, Emily (School of Physics, University of Exeter)

We present the results of a large-scale survey of the very dense molecular gas in Perseus, Orion A and B, Serpens and Ophiuchus using HCO+ and HCN (J = 4 - 3) transitions. We have used this emission to trace the structure and kinematics of gas at the extremely high densities found in pre- and protostellar cores; as well as tracing outflows powered by these early star-forming cores. We present a comparison of the HCO+/HCN data, highlighting regions where there is a marked discrepancy in the spectra of the two emission lines. This is particularly noticeable in some of the more powerful outflows driven by Class 0 sources, where the HCN is greatly enhanced in the linewings in comparison with HCO+. We also use the HCO+ to positively identify protostellar outflows and their driving sources. We present a statistical analysis of the outflow properties that we derive from this tracer. We show that our results are comparable to those obtained from similar outflow analyses using 12CO.

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