Multi-Scale CLEAN: A comparison of its performance against classical CLEAN in galaxies using THINGS
Abstract
A practical evaluation of the Multi-Scale CLEAN algorithm is presented. The data used in the comparisons are taken from The HI Nearby Galaxy Survey (THINGS). The implementation of Multi-Scale CLEAN in the CASA software package is used, although comparisons are made against the very similar Multi-Resolution CLEAN algorithm implemented in AIPS. Both are compared against the classical CLEAN algorithm (as implemented in AIPS). The results of this comparison show that several of the well-known characteristics and issues of using classical CLEAN are significantly lessened (or eliminated completely) when using the Multi-Scale CLEAN algorithm. Importantly, Multi-Scale CLEAN reduces significantly the effects of the clean `bowl' caused by missing short-spacings, and the `pedestal' of low-level un-cleaned flux (which affects flux scales and resolution). Multi-Scale CLEAN can clean down to the noise level without the divergence suffered by classical CLEAN. We discuss practical applications of the added contrast provided by Multi-Scale CLEAN using two selected astronomical examples: HI holes in the interstellar medium and anomalous gas structures outside the main galactic disk.
Cite
@article{arxiv.0810.2825,
title = {Multi-Scale CLEAN: A comparison of its performance against classical CLEAN in galaxies using THINGS},
author = {J. W. Rich and W. J. G. de Blok and T. J. Cornwell and E. Brinks and F. Walter and I. Bagetakos and R. C. Kennicutt},
journal= {arXiv preprint arXiv:0810.2825},
year = {2009}
}
Comments
Accepted for publication in the AJ special THINGS issue. For a high-resolution version visit: http://www.mpia.de/THINGS/Publications.html