Investigating the contribution of extended radio sources to the Epoch of Reionization power spectrum
We investigate the contribution of extended radio sources such as Centaurus A, and Galactic supernova remnants (SNRs) to our ability to detect the statistical 21-cm signal from the Epoch of Reionisation (EoR) with the Murchison Widefield Array (MWA). These sources are typically ignored because they...
| Main Authors: | , , |
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| Format: | Journal Article |
| Language: | English |
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OXFORD UNIV PRESS
2022
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| Subjects: | |
| Online Access: | http://purl.org/au-research/grants/arc/CE170100013 http://hdl.handle.net/20.500.11937/91577 |
| _version_ | 1848765553257218048 |
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| author | Cook, J.H. Trott, Cathryn Line, Jack |
| author_facet | Cook, J.H. Trott, Cathryn Line, Jack |
| author_sort | Cook, J.H. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | We investigate the contribution of extended radio sources such as Centaurus A, and Galactic supernova remnants (SNRs) to our ability to detect the statistical 21-cm signal from the Epoch of Reionisation (EoR) with the Murchison Widefield Array (MWA). These sources are typically ignored because they are in highly attenuated parts of the MWA primary beam, however, in aggregate, these sources have apparent flux densities of 10, Jy on angular scales we expect to detect the 21-cm signal. We create bespoke multicomponent 2D Gaussian models for Galactic SNRs and for Centaurus A, and simulate the visibilities for two MWA snapshot observations. We grid those visibilities and then Fourier transform them with respect to frequency, averaging them both spherically and cylindrically to produce the 1D and 2D power spectra. We compare the simulated 1D power spectra to the expected 21-$\rm {cm}$ power spectrum. We find that although these extended sources are in highly attenuated parts of the MWA primary beam pattern, collectively they have enough power (∼104-105 m mK2 it h-3, Mpc3) on EoR significant modes (| k| ≲ 0.1\, h\,\rm Mpc-1) to prohibit detection of the 21-rm cm signal (∼104 rm mK2\, h-3,\rm Mpc3). We find that 50-90 per cent of sources must be removed in order to reduce leakage to a level of ∼ 10-20 per cent of the 21-rm cm power spectrum on EoR significant modes. The effects of wide-field extended sources will have implications on the detectability of the 21-rm cm signal for the MWA and with the future Square Kilometre Array (SKA). |
| first_indexed | 2025-11-14T11:37:05Z |
| format | Journal Article |
| id | curtin-20.500.11937-91577 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T11:37:05Z |
| publishDate | 2022 |
| publisher | OXFORD UNIV PRESS |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-915772023-05-16T02:29:15Z Investigating the contribution of extended radio sources to the Epoch of Reionization power spectrum Cook, J.H. Trott, Cathryn Line, Jack Science & Technology Physical Sciences Astronomy & Astrophysics methods: statistical techniques: interferometric stars: supernovae: general cosmology: dark ages, reionization, first stars COSMOLOGY CENTAURUS ARRAY INTERFEROMETRY SUBTRACTION EMISSION astro-ph.CO astro-ph.CO We investigate the contribution of extended radio sources such as Centaurus A, and Galactic supernova remnants (SNRs) to our ability to detect the statistical 21-cm signal from the Epoch of Reionisation (EoR) with the Murchison Widefield Array (MWA). These sources are typically ignored because they are in highly attenuated parts of the MWA primary beam, however, in aggregate, these sources have apparent flux densities of 10, Jy on angular scales we expect to detect the 21-cm signal. We create bespoke multicomponent 2D Gaussian models for Galactic SNRs and for Centaurus A, and simulate the visibilities for two MWA snapshot observations. We grid those visibilities and then Fourier transform them with respect to frequency, averaging them both spherically and cylindrically to produce the 1D and 2D power spectra. We compare the simulated 1D power spectra to the expected 21-$\rm {cm}$ power spectrum. We find that although these extended sources are in highly attenuated parts of the MWA primary beam pattern, collectively they have enough power (∼104-105 m mK2 it h-3, Mpc3) on EoR significant modes (| k| ≲ 0.1\, h\,\rm Mpc-1) to prohibit detection of the 21-rm cm signal (∼104 rm mK2\, h-3,\rm Mpc3). We find that 50-90 per cent of sources must be removed in order to reduce leakage to a level of ∼ 10-20 per cent of the 21-rm cm power spectrum on EoR significant modes. The effects of wide-field extended sources will have implications on the detectability of the 21-rm cm signal for the MWA and with the future Square Kilometre Array (SKA). 2022 Journal Article http://hdl.handle.net/20.500.11937/91577 10.1093/mnras/stac1330 English http://purl.org/au-research/grants/arc/CE170100013 http://purl.org/au-research/grants/arc/FT180100321 http://purl.org/au-research/grants/arc/LE160100031 OXFORD UNIV PRESS fulltext |
| spellingShingle | Science & Technology Physical Sciences Astronomy & Astrophysics methods: statistical techniques: interferometric stars: supernovae: general cosmology: dark ages, reionization, first stars COSMOLOGY CENTAURUS ARRAY INTERFEROMETRY SUBTRACTION EMISSION astro-ph.CO astro-ph.CO Cook, J.H. Trott, Cathryn Line, Jack Investigating the contribution of extended radio sources to the Epoch of Reionization power spectrum |
| title | Investigating the contribution of extended radio sources to the Epoch of Reionization power spectrum |
| title_full | Investigating the contribution of extended radio sources to the Epoch of Reionization power spectrum |
| title_fullStr | Investigating the contribution of extended radio sources to the Epoch of Reionization power spectrum |
| title_full_unstemmed | Investigating the contribution of extended radio sources to the Epoch of Reionization power spectrum |
| title_short | Investigating the contribution of extended radio sources to the Epoch of Reionization power spectrum |
| title_sort | investigating the contribution of extended radio sources to the epoch of reionization power spectrum |
| topic | Science & Technology Physical Sciences Astronomy & Astrophysics methods: statistical techniques: interferometric stars: supernovae: general cosmology: dark ages, reionization, first stars COSMOLOGY CENTAURUS ARRAY INTERFEROMETRY SUBTRACTION EMISSION astro-ph.CO astro-ph.CO |
| url | http://purl.org/au-research/grants/arc/CE170100013 http://purl.org/au-research/grants/arc/CE170100013 http://purl.org/au-research/grants/arc/CE170100013 http://hdl.handle.net/20.500.11937/91577 |