2008/10/16 by J. W. Rich, W. J. G. de Blok, T. J. Cornwell +7 · 2 citations
Physics and Astronomy · #Experimental and Theoretical Physics Studies #astro-ph
paper · pdf · doi:10.1088/0004-6256/136/6/2897
Accepted for publication in the AJ special THINGS issue. For a high-resolution version visit: http://www.mpia.de/THINGS/Publications.html
arxiv created 2008/10/16 · openalex publication_date 2008/11/19 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
A practical evaluation of the multi-scale clean algorithm is presented. The data used in the comparisons are taken from The H i Nearby Galaxy Survey. 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 significantly reduces the effects of the clean "bowl" that is 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: H i holes in the interstellar medium and anomalous gas structures outside the main galactic disk.