The JCMT Gould Belt Survey: a quantitative comparison between SCUBA-2 data reduction methods
JCMT Gould Belt survey Team
Monthly Notices of the Royal Astronomical Society
Oxford University Press for Royal Astronomical Society
Performing ground-based submillimetre observations is a difficult task as the measurements are subject to absorption and emission from water vapour in the Earth's atmosphere and time variation in weather and instrument stability. Removing these features and other artefacts from the data is a vital process which affects the characteristics of the recovered astronomical structure we seek to study. In this paper, we explore two data reduction methods for data taken with the Submillimetre Common-User Bolometer Array-2 (SCUBA-2) at the James Clerk Maxwell Telescope (JCMT). The JCMT Legacy Reduction 1 (JCMT LR1) and The Gould Belt Legacy Survey Legacy Release 1 (GBS LR1) reduction both use the same software (STARLINK) but differ in their choice of data reduction parameters. We find that the JCMT LR1 reduction is suitable for determining whether or not compact emission is present in a given region and the GBS LR1 reduction is tuned in a robust way to uncover more extended emission, which better serves more in-depth physical analyses of star-forming regions. Using the GBS LR1 method, we find that compact sources are recovered well, even at a peak brightness of only three times the noise, whereas the reconstruction of larger objects requires much care when drawing boundaries around the expected astronomical signal in the data reduction process. Incorrect boundaries can lead to false structure identification or it can cause structure to be missed. In the JCMT LR1 reduction, the extent of the true structure of objects larger than a point source is never fully recovered.
Natural Sciences and Engineering Research Council (NSERC) of Canada
Science and Technology Facilities Council of the United Kingdom
National Research Council of Canada
Netherlands Organization for Scientific Research
Canada Foundation for Innovation
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society © 2015 The Authors. Journal compilation © 2015 RAS. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
Vol. 454, Iss.3, pp. 2557 - 2579