Interplanetary Scintillation with the Murchison Widefield Array I: a sub-arcsecond survey over 900 deg2 at 79 and 158 MHz
We present the first dedicated observations of Interplanetary Scintillation (IPS) with the Murchison Widefield Array. We have developed a synthesis imaging technique, tailored to the properties of modern 'large-N' low-frequency radio telescopes. This allows us to image the variability on I...
| Main Authors: | , , , , , , , , |
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| Format: | Journal Article |
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Oxford University Press
2018
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| Online Access: | http://hdl.handle.net/20.500.11937/67446 |
| _version_ | 1848761568181878784 |
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| author | Morgan, John Macquart, Jean-Pierre Ekers, Ronald Chhetri, Rajan Tokumaru, M. Manoharan, P. Tremblay, Steven Bisi, M. Jackson, B. |
| author_facet | Morgan, John Macquart, Jean-Pierre Ekers, Ronald Chhetri, Rajan Tokumaru, M. Manoharan, P. Tremblay, Steven Bisi, M. Jackson, B. |
| author_sort | Morgan, John |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | We present the first dedicated observations of Interplanetary Scintillation (IPS) with the Murchison Widefield Array. We have developed a synthesis imaging technique, tailored to the properties of modern 'large-N' low-frequency radio telescopes. This allows us to image the variability on IPS time-scales across 900 deg 2 simultaneously. We show that for our observations, a sampling rate of just 2 Hz is sufficient to resolve the IPS signature of most sources. We develop tests to ensure that IPS variability is separated from ionospheric or instrumental variability. We validate our results by comparison with existing catalogues of IPS sources, and near-contemporaneous observations by other IPS facilities. Using just 5 min of data, we produce catalogues at both 79 and 158 MHz, each containing over 350 scintillating sources. At the field centre, we detect approximately one scintillating source per square degree, with a minimum scintillating flux density at 158MHz of 110 mJy, corresponding to a compact flux density of approximately 400 mJy. Each of these sources is a known radio source, however only a minority were previously known to contain sub-arcsecond components. We discuss our findings and the prospects they hold for future astrophysical and heliospheric studies. |
| first_indexed | 2025-11-14T10:33:44Z |
| format | Journal Article |
| id | curtin-20.500.11937-67446 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T10:33:44Z |
| publishDate | 2018 |
| publisher | Oxford University Press |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-674462018-09-26T06:32:15Z Interplanetary Scintillation with the Murchison Widefield Array I: a sub-arcsecond survey over 900 deg2 at 79 and 158 MHz Morgan, John Macquart, Jean-Pierre Ekers, Ronald Chhetri, Rajan Tokumaru, M. Manoharan, P. Tremblay, Steven Bisi, M. Jackson, B. We present the first dedicated observations of Interplanetary Scintillation (IPS) with the Murchison Widefield Array. We have developed a synthesis imaging technique, tailored to the properties of modern 'large-N' low-frequency radio telescopes. This allows us to image the variability on IPS time-scales across 900 deg 2 simultaneously. We show that for our observations, a sampling rate of just 2 Hz is sufficient to resolve the IPS signature of most sources. We develop tests to ensure that IPS variability is separated from ionospheric or instrumental variability. We validate our results by comparison with existing catalogues of IPS sources, and near-contemporaneous observations by other IPS facilities. Using just 5 min of data, we produce catalogues at both 79 and 158 MHz, each containing over 350 scintillating sources. At the field centre, we detect approximately one scintillating source per square degree, with a minimum scintillating flux density at 158MHz of 110 mJy, corresponding to a compact flux density of approximately 400 mJy. Each of these sources is a known radio source, however only a minority were previously known to contain sub-arcsecond components. We discuss our findings and the prospects they hold for future astrophysical and heliospheric studies. 2018 Journal Article http://hdl.handle.net/20.500.11937/67446 10.1093/mnras/stx2284 Oxford University Press fulltext |
| spellingShingle | Morgan, John Macquart, Jean-Pierre Ekers, Ronald Chhetri, Rajan Tokumaru, M. Manoharan, P. Tremblay, Steven Bisi, M. Jackson, B. Interplanetary Scintillation with the Murchison Widefield Array I: a sub-arcsecond survey over 900 deg2 at 79 and 158 MHz |
| title | Interplanetary Scintillation with the Murchison Widefield Array I: a sub-arcsecond survey over 900 deg2 at 79 and 158 MHz |
| title_full | Interplanetary Scintillation with the Murchison Widefield Array I: a sub-arcsecond survey over 900 deg2 at 79 and 158 MHz |
| title_fullStr | Interplanetary Scintillation with the Murchison Widefield Array I: a sub-arcsecond survey over 900 deg2 at 79 and 158 MHz |
| title_full_unstemmed | Interplanetary Scintillation with the Murchison Widefield Array I: a sub-arcsecond survey over 900 deg2 at 79 and 158 MHz |
| title_short | Interplanetary Scintillation with the Murchison Widefield Array I: a sub-arcsecond survey over 900 deg2 at 79 and 158 MHz |
| title_sort | interplanetary scintillation with the murchison widefield array i: a sub-arcsecond survey over 900 deg2 at 79 and 158 mhz |
| url | http://hdl.handle.net/20.500.11937/67446 |