An Improved Method for 21cm Foreground Removal
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...
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| Format: | Article |
| Language: | en_US |
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Oxford University Press
2013
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| Online Access: | http://hdl.handle.net/1721.1/76695 https://orcid.org/0000-0002-4117-570X https://orcid.org/0000-0001-7670-7190 https://orcid.org/0000-0001-6876-0928 |
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| author | Liu, Adrian Chi-Yan Tegmark, Max Erik Bowman, Judd D. Hewitt, Jacqueline N. Zaldarriaga, Matias, 1971- |
| author2 | Massachusetts Institute of Technology. Department of Physics |
| author_facet | Massachusetts Institute of Technology. Department of Physics Liu, Adrian Chi-Yan Tegmark, Max Erik Bowman, Judd D. Hewitt, Jacqueline N. Zaldarriaga, Matias, 1971- |
| author_sort | Liu, Adrian Chi-Yan |
| collection | MIT |
| description | 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. |
| first_indexed | 2024-09-23T09:47:54Z |
| format | Article |
| id | mit-1721.1/76695 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T09:47:54Z |
| publishDate | 2013 |
| publisher | Oxford University Press |
| record_format | dspace |
| spelling | mit-1721.1/766952022-09-26T13:47:15Z An Improved Method for 21cm Foreground Removal Liu, Adrian Chi-Yan Tegmark, Max Erik Bowman, Judd D. Hewitt, Jacqueline N. Zaldarriaga, Matias, 1971- Massachusetts Institute of Technology. Department of Physics MIT Kavli Institute for Astrophysics and Space Research Liu, Adrian Chi-Yan Tegmark, Max Erik Hewitt, Jacqueline N. 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. National Science Foundation (U.S.) (Grant AST-0134999) National Science Foundation (U.S.) (Grant AST-05-06556) David & Lucile Packard Foundation Research Corporation 2013-01-30T21:38:51Z 2013-01-30T21:38:51Z 2009-09 2009-05 Article http://purl.org/eprint/type/JournalArticle 0035-8711 1365-8711 http://hdl.handle.net/1721.1/76695 Liu, Adrian et al. “An Improved Method for 21-cm Foreground Removal.” Monthly Notices of the Royal Astronomical Society 398.1 (2009): 401–406. https://orcid.org/0000-0002-4117-570X https://orcid.org/0000-0001-7670-7190 https://orcid.org/0000-0001-6876-0928 en_US http://dx.doi.org/10.1111/j.1365-2966.2009.15156.x Monthly Notices of the Royal Astronomical Society Creative Commons Attribution-Noncommercial-Share Alike 3.0 http://creativecommons.org/licenses/by-nc-sa/3.0/ application/pdf Oxford University Press arXiv |
| spellingShingle | Liu, Adrian Chi-Yan Tegmark, Max Erik Bowman, Judd D. Hewitt, Jacqueline N. Zaldarriaga, Matias, 1971- An Improved Method for 21cm Foreground Removal |
| title | An Improved Method for 21cm Foreground Removal |
| title_full | An Improved Method for 21cm Foreground Removal |
| title_fullStr | An Improved Method for 21cm Foreground Removal |
| title_full_unstemmed | An Improved Method for 21cm Foreground Removal |
| title_short | An Improved Method for 21cm Foreground Removal |
| title_sort | improved method for 21cm foreground removal |
| url | http://hdl.handle.net/1721.1/76695 https://orcid.org/0000-0002-4117-570X https://orcid.org/0000-0001-7670-7190 https://orcid.org/0000-0001-6876-0928 |
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