A survey for transients and variables with the Murchison Widefield Array 32-tile prototype at 154 MHz
We present a search for transient and variable radio sources at 154 MHz with the Murchison Widefield Array 32-tile prototype. Fifty-one images were obtained that cover a field of view of 1430 deg2 centred on Hydra A. The observations were obtained over three days in 2010 March and three days in 2011...
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| Format: | Journal Article |
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Oxford University Press
2013
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| Subjects: | |
| Online Access: | http://hdl.handle.net/20.500.11937/35596 |
| _version_ | 1848754538762207232 |
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| author | Trott, Cathryn Hurley-Walker, Natasha Wayth, Randall Macquart, Jean-Pierre Arcus, Wayne Emrich, David Herne, David Lynch, Mervyn Ord, Stephen Tingay, Steven Waterson, Mark Williams, Andrew Bell, M. Murphy, T. Kaplan, D. Hancock, P. Gaensler, B. Banyer, J. Bannister, K. Barnes, D. Bernardi, G. Bowman, J. Briggs, F. Bunton, J. Cappallo, R. Corey, B. Deshpande, A. deSouza, L. Goeke, R. Greenhill, L. Hazelton, B. Hewitt, J. Johnston-Hollitt, M. Kasper, J. Kincaid, B. Koenig, R. Kratzenberg, E. Lonsdale, C. McWhirter, S. Mitchell, D. Morales, M. Morgan, E. Oberoi, D. Pathikulangara, J. Prabu, T. Remillard, R. Rogers, A. Roshi, A. Salah, J. Sault, R. Udaya Shankar, N. Srivani, K. Stevens, J. Subrahmanyan, R. Webster, R. Whitney, A. Williams, C. Wyithe, J. |
| author_facet | Trott, Cathryn Hurley-Walker, Natasha Wayth, Randall Macquart, Jean-Pierre Arcus, Wayne Emrich, David Herne, David Lynch, Mervyn Ord, Stephen Tingay, Steven Waterson, Mark Williams, Andrew Bell, M. Murphy, T. Kaplan, D. Hancock, P. Gaensler, B. Banyer, J. Bannister, K. Barnes, D. Bernardi, G. Bowman, J. Briggs, F. Bunton, J. Cappallo, R. Corey, B. Deshpande, A. deSouza, L. Goeke, R. Greenhill, L. Hazelton, B. Hewitt, J. Johnston-Hollitt, M. Kasper, J. Kincaid, B. Koenig, R. Kratzenberg, E. Lonsdale, C. McWhirter, S. Mitchell, D. Morales, M. Morgan, E. Oberoi, D. Pathikulangara, J. Prabu, T. Remillard, R. Rogers, A. Roshi, A. Salah, J. Sault, R. Udaya Shankar, N. Srivani, K. Stevens, J. Subrahmanyan, R. Webster, R. Whitney, A. Williams, C. Wyithe, J. |
| author_sort | Trott, Cathryn |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | We present a search for transient and variable radio sources at 154 MHz with the Murchison Widefield Array 32-tile prototype. Fifty-one images were obtained that cover a field of view of 1430 deg2 centred on Hydra A. The observations were obtained over three days in 2010 March and three days in 2011 April and May. The mean cadence of the observations was 26 minutes and there was additional temporal information on day and year timescales. We explore the variability of a sample of 105 low frequency radio sources within the field. Four bright (S > 6 Jy) candidate variable radio sources were identified that displayed low levels of short timescale variability (26 minutes). We conclude that this variability is likely caused by simplifications in the calibration strategy or ionospheric effects. On the timescale of one year we find two sources that show significant variability. We attribute this variability to either refractive scintillation or intrinsic variability. No radio transients were identified and we place an upper limit on the surface density of sources p < 7.5 × 10-5 deg-2 with flux densities > 5.5 Jy, and characteristic timescales of both 26 minutes and one year. |
| first_indexed | 2025-11-14T08:42:00Z |
| format | Journal Article |
| id | curtin-20.500.11937-35596 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T08:42:00Z |
| publishDate | 2013 |
| publisher | Oxford University Press |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-355962017-09-13T15:36:21Z A survey for transients and variables with the Murchison Widefield Array 32-tile prototype at 154 MHz Trott, Cathryn Hurley-Walker, Natasha Wayth, Randall Macquart, Jean-Pierre Arcus, Wayne Emrich, David Herne, David Lynch, Mervyn Ord, Stephen Tingay, Steven Waterson, Mark Williams, Andrew Bell, M. Murphy, T. Kaplan, D. Hancock, P. Gaensler, B. Banyer, J. Bannister, K. Barnes, D. Bernardi, G. Bowman, J. Briggs, F. Bunton, J. Cappallo, R. Corey, B. Deshpande, A. deSouza, L. Goeke, R. Greenhill, L. Hazelton, B. Hewitt, J. Johnston-Hollitt, M. Kasper, J. Kincaid, B. Koenig, R. Kratzenberg, E. Lonsdale, C. McWhirter, S. Mitchell, D. Morales, M. Morgan, E. Oberoi, D. Pathikulangara, J. Prabu, T. Remillard, R. Rogers, A. Roshi, A. Salah, J. Sault, R. Udaya Shankar, N. Srivani, K. Stevens, J. Subrahmanyan, R. Webster, R. Whitney, A. Williams, C. Wyithe, J. catalogues radio continuum: general instrumentation: interferometers techniques: image processing We present a search for transient and variable radio sources at 154 MHz with the Murchison Widefield Array 32-tile prototype. Fifty-one images were obtained that cover a field of view of 1430 deg2 centred on Hydra A. The observations were obtained over three days in 2010 March and three days in 2011 April and May. The mean cadence of the observations was 26 minutes and there was additional temporal information on day and year timescales. We explore the variability of a sample of 105 low frequency radio sources within the field. Four bright (S > 6 Jy) candidate variable radio sources were identified that displayed low levels of short timescale variability (26 minutes). We conclude that this variability is likely caused by simplifications in the calibration strategy or ionospheric effects. On the timescale of one year we find two sources that show significant variability. We attribute this variability to either refractive scintillation or intrinsic variability. No radio transients were identified and we place an upper limit on the surface density of sources p < 7.5 × 10-5 deg-2 with flux densities > 5.5 Jy, and characteristic timescales of both 26 minutes and one year. 2013 Journal Article http://hdl.handle.net/20.500.11937/35596 10.1093/mnras/stt2200 Oxford University Press fulltext |
| spellingShingle | catalogues radio continuum: general instrumentation: interferometers techniques: image processing Trott, Cathryn Hurley-Walker, Natasha Wayth, Randall Macquart, Jean-Pierre Arcus, Wayne Emrich, David Herne, David Lynch, Mervyn Ord, Stephen Tingay, Steven Waterson, Mark Williams, Andrew Bell, M. Murphy, T. Kaplan, D. Hancock, P. Gaensler, B. Banyer, J. Bannister, K. Barnes, D. Bernardi, G. Bowman, J. Briggs, F. Bunton, J. Cappallo, R. Corey, B. Deshpande, A. deSouza, L. Goeke, R. Greenhill, L. Hazelton, B. Hewitt, J. Johnston-Hollitt, M. Kasper, J. Kincaid, B. Koenig, R. Kratzenberg, E. Lonsdale, C. McWhirter, S. Mitchell, D. Morales, M. Morgan, E. Oberoi, D. Pathikulangara, J. Prabu, T. Remillard, R. Rogers, A. Roshi, A. Salah, J. Sault, R. Udaya Shankar, N. Srivani, K. Stevens, J. Subrahmanyan, R. Webster, R. Whitney, A. Williams, C. Wyithe, J. A survey for transients and variables with the Murchison Widefield Array 32-tile prototype at 154 MHz |
| title | A survey for transients and variables with the Murchison Widefield Array 32-tile prototype at 154 MHz |
| title_full | A survey for transients and variables with the Murchison Widefield Array 32-tile prototype at 154 MHz |
| title_fullStr | A survey for transients and variables with the Murchison Widefield Array 32-tile prototype at 154 MHz |
| title_full_unstemmed | A survey for transients and variables with the Murchison Widefield Array 32-tile prototype at 154 MHz |
| title_short | A survey for transients and variables with the Murchison Widefield Array 32-tile prototype at 154 MHz |
| title_sort | survey for transients and variables with the murchison widefield array 32-tile prototype at 154 mhz |
| topic | catalogues radio continuum: general instrumentation: interferometers techniques: image processing |
| url | http://hdl.handle.net/20.500.11937/35596 |