An improved method for 21-cm foreground removal
Abstract
21-cm tomography is expected to be difficult in part because of serious foreground contamination. Previous studies have found that line-of-sight approaches are capable of cleaning foregrounds to an acceptable level on large spatial scales, but not on small spatial scales. In this paper, we introduce a Fourier space formalism for describing the line-of-sight methods, and use it to introduce an improved new method for 21-cm foreground cleaning. Heuristically, this method involves fitting foregrounds in Fourier space using weighted polynomial fits, with each pixel weighted according to its information content. We show that the new method reproduces the old one on large angular scales, and gives marked improvements on small scales at essentially no extra computational cost.
Additional Information
© 2009 The Authors. Accepted 2009 May 28. Received 2009 May 20; in original form 2009 April 3. We wish to thank Mike Matejek, Miguel Morales, Leslie Rogers and Christopher Williams for helpful comments. MT was supported by NSF grants AST-0134999 and AST-05-06556 as well as fellowships from the David and Lucile Packard Foundation and the Research Corporation. MZ was supported by NASA NNG05GJ40G and NSF AST-05-06556 as well as the David and Lucile Packard, Alfred P. Sloan and John D. and Catherine T. MacArthur foundations.Attached Files
Published - Liu2009p5822Mon_Not_R_Astron_Soc.pdf
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Additional details
- Eprint ID
- 15748
- Resolver ID
- CaltechAUTHORS:20090911-073815681
- AST-0134999
- NSF
- AST-05-06556
- NSF
- NNG05GJ40G
- NASA
- AST-05-06556
- NSF
- David and Lucile Packard foundation
- Alfred P. Sloan foundation
- John D. and Catherine T. MacArthur foundation
- Created
-
2009-09-14Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field