Subtraction of Bright Point Sources from Synthesis Images of the Epoch of Reionization
Bright point sources associated with extragalactic active galactic nuclei and radio galaxies are an important foreground for low-frequency radio experiments aimed at detecting the redshifted 21-cm emission from neutral hydrogen during the epoch of reionization. The frequency dependence of the synthe...
| Main Authors: | , , , , , |
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| Format: | Journal Article |
| Published: |
CSIRO
2011
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| Online Access: | http://hdl.handle.net/20.500.11937/46168 |
| _version_ | 1848757484145082368 |
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| author | Pindor, B. Wyithe, J. Mitchell, D. Ord, Stephen Wayth, Randall Greenhill, L. |
| author_facet | Pindor, B. Wyithe, J. Mitchell, D. Ord, Stephen Wayth, Randall Greenhill, L. |
| author_sort | Pindor, B. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Bright point sources associated with extragalactic active galactic nuclei and radio galaxies are an important foreground for low-frequency radio experiments aimed at detecting the redshifted 21-cm emission from neutral hydrogen during the epoch of reionization. The frequency dependence of the synthesized beam implies that the sidelobes of these sources will move across the field of view as a function of observing frequency, hence frustrating line-of-sight foreground subtraction techniques. We describe a method for subtracting these point sources from dirty maps produced by an instrument such as the MWA. This technique combines matched filters with an iterative centroiding scheme to locate and characterize point sources in the presence of a diffuse background. Simulations show that this technique can improve the dynamic range of epoch-of-reionization maps by 2–3 orders of magnitude. |
| first_indexed | 2025-11-14T09:28:49Z |
| format | Journal Article |
| id | curtin-20.500.11937-46168 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T09:28:49Z |
| publishDate | 2011 |
| publisher | CSIRO |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-461682017-09-13T16:07:34Z Subtraction of Bright Point Sources from Synthesis Images of the Epoch of Reionization Pindor, B. Wyithe, J. Mitchell, D. Ord, Stephen Wayth, Randall Greenhill, L. Bright point sources associated with extragalactic active galactic nuclei and radio galaxies are an important foreground for low-frequency radio experiments aimed at detecting the redshifted 21-cm emission from neutral hydrogen during the epoch of reionization. The frequency dependence of the synthesized beam implies that the sidelobes of these sources will move across the field of view as a function of observing frequency, hence frustrating line-of-sight foreground subtraction techniques. We describe a method for subtracting these point sources from dirty maps produced by an instrument such as the MWA. This technique combines matched filters with an iterative centroiding scheme to locate and characterize point sources in the presence of a diffuse background. Simulations show that this technique can improve the dynamic range of epoch-of-reionization maps by 2–3 orders of magnitude. 2011 Journal Article http://hdl.handle.net/20.500.11937/46168 10.1071/AS10023 CSIRO unknown |
| spellingShingle | Pindor, B. Wyithe, J. Mitchell, D. Ord, Stephen Wayth, Randall Greenhill, L. Subtraction of Bright Point Sources from Synthesis Images of the Epoch of Reionization |
| title | Subtraction of Bright Point Sources from Synthesis Images of the Epoch of Reionization |
| title_full | Subtraction of Bright Point Sources from Synthesis Images of the Epoch of Reionization |
| title_fullStr | Subtraction of Bright Point Sources from Synthesis Images of the Epoch of Reionization |
| title_full_unstemmed | Subtraction of Bright Point Sources from Synthesis Images of the Epoch of Reionization |
| title_short | Subtraction of Bright Point Sources from Synthesis Images of the Epoch of Reionization |
| title_sort | subtraction of bright point sources from synthesis images of the epoch of reionization |
| url | http://hdl.handle.net/20.500.11937/46168 |