Molecular line contamination in the SCUBA-2 450 and 850 μm continuum data
Di Francesco, J
Monthly Notices of the Royal Astronomical Society
Oxford University Press (OUP) / Royal Astronomical Society
Observations of the dust emission using millimetre/submillimetre bolometer arrays can be contaminated by molecular line flux, such as flux from 12CO. As the brightest molecular line in the submillimetre, it is important to quantify the contribution of CO flux to the dust continuum bands. Conversion factors were used to convert molecular line integrated intensities to flux detected by bolometer arrays in mJybeam -1. These factors were calculated for 12CO line integrated intensities to the SCUBA-2 850 and 450μm bands. The conversion factors were then applied to HARP 12CO 3-2 maps of NGC 1333 in the Perseus complex and NGC 2071 and NGC 2024 in the Orion B molecular cloud complex to quantify the respective 12CO flux contribution to the 850μm dust continuum emission. Sources with high molecular line contamination were analysed in further detail for molecular outflows and heating by nearby stars to determine the cause of the 12CO contribution. The majority of sources had a 12CO 3-2 flux contribution under 20per cent. However, in regions of molecular outflows, the 12CO can dominate the source dust continuum (up to 79per cent contamination) with 12CO fluxes reaching ∼68mJybeam -1. © 2012 The Authors Monthly Notices of the Royal Astronomical Society © 2012 RAS.
We would like to thank Antonio Chrysostomou and Simon Coudé for their helpful input for this paper. The JCMT is operated by the Joint Astronomy Centre (JAC) on behalf of the Science and Technology Facilities Council (STFC) of the United Kingdom, the National Research Council of Canada and the Netherlands Organisation for Scientific Research. This work made use of SIMBAD that is operated at CDS, Strasbourg, France. We acknowledge the data analysis facilities provided by the Starlink Project which is run by CCLRC on behalf of PPARC. In addition, the following Starlink package AUTOPHOTOM has been used. This research made use of APLpy, an open-source plotting package for python hosted at http://aplpy.github.com. ED acknowledges the support of a college studentship from the University of Exeter.
This is the final version of the article. Available from OUP via the DOI in this record.
Vol. 426 (1), pp. 23 - 39