A search for long-time-scale, low-frequency radio transients
We present a search for transient and highly variable sources at low radio frequencies (150-200 MHz) that explores long timescales of 1-3 years. We conducted this search by comparing the TIFR GMRT Sky Survey Alternative Data Release 1 (TGSS ADR1) and the GaLactic and Extragalactic All-sky Murchison...
| Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
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| Format: | Journal Article |
| Published: |
Oxford University Press
2017
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| Online Access: | http://hdl.handle.net/20.500.11937/52622 |
| _version_ | 1848758972227518464 |
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| author | Murphy, T. Kaplan, D. Croft, S. Lynch, C. Callingham, J. Bannister, K. Bell, M. Hurley-Walker, Natasha Hancock, Paul Line, J. Rowlinson, A. Lenc, E. Intema, H. Jagannathan, P. Ekers, Ronald Tingay, Steven Yuan, F. Wolf, C. Onken, C. Dwarakanath, K. For, B. Gaensler, B. Hindson, L. Johnston-Hollitt, M. Kapinska, A. McKinley, B. Morgan, J. Offringa, A. Procopio, P. Staveley-Smith, L. Wayth, Randall Wu, C. Zheng, Q. |
| author_facet | Murphy, T. Kaplan, D. Croft, S. Lynch, C. Callingham, J. Bannister, K. Bell, M. Hurley-Walker, Natasha Hancock, Paul Line, J. Rowlinson, A. Lenc, E. Intema, H. Jagannathan, P. Ekers, Ronald Tingay, Steven Yuan, F. Wolf, C. Onken, C. Dwarakanath, K. For, B. Gaensler, B. Hindson, L. Johnston-Hollitt, M. Kapinska, A. McKinley, B. Morgan, J. Offringa, A. Procopio, P. Staveley-Smith, L. Wayth, Randall Wu, C. Zheng, Q. |
| author_sort | Murphy, T. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | We present a search for transient and highly variable sources at low radio frequencies (150-200 MHz) that explores long timescales of 1-3 years. We conducted this search by comparing the TIFR GMRT Sky Survey Alternative Data Release 1 (TGSS ADR1) and the GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey catalogues. To account for the different completeness thresholds in the individual surveys, we searched for compact GLEAM sources above a flux density limit of 100 mJy that were not present in the TGSS ADR1; and also for compact TGSS ADR1 sources above a flux density limit of 200 mJy that had no counterpart in GLEAM. From a total sample of 234 333 GLEAM sources and 275 612 TGSS ADR1 sources in the overlap region between the two surveys, there were 99658 GLEAM sources and 38 978 TGSS ADR sources that passed our flux density cutoff and compactness criteria. Analysis of these sources resulted in three candidate transient sources. Further analysis ruled out two candidates as imaging artefacts. We analyse the third candidate and show it is likely to be real, with a flux density of 182 +/- 26 mJy at 147.5 MHz. This gives a transient surface density of rho = (6.2 +/- 6) x 10-5 deg-2 . We present initial follow-up observations and discuss possible causes for this candidate. The small number of spurious sources from this search demonstrates the high reliability of these two new low-frequency radio catalogues. |
| first_indexed | 2025-11-14T09:52:28Z |
| format | Journal Article |
| id | curtin-20.500.11937-52622 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T09:52:28Z |
| publishDate | 2017 |
| publisher | Oxford University Press |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-526222017-09-13T15:48:30Z A search for long-time-scale, low-frequency radio transients Murphy, T. Kaplan, D. Croft, S. Lynch, C. Callingham, J. Bannister, K. Bell, M. Hurley-Walker, Natasha Hancock, Paul Line, J. Rowlinson, A. Lenc, E. Intema, H. Jagannathan, P. Ekers, Ronald Tingay, Steven Yuan, F. Wolf, C. Onken, C. Dwarakanath, K. For, B. Gaensler, B. Hindson, L. Johnston-Hollitt, M. Kapinska, A. McKinley, B. Morgan, J. Offringa, A. Procopio, P. Staveley-Smith, L. Wayth, Randall Wu, C. Zheng, Q. We present a search for transient and highly variable sources at low radio frequencies (150-200 MHz) that explores long timescales of 1-3 years. We conducted this search by comparing the TIFR GMRT Sky Survey Alternative Data Release 1 (TGSS ADR1) and the GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey catalogues. To account for the different completeness thresholds in the individual surveys, we searched for compact GLEAM sources above a flux density limit of 100 mJy that were not present in the TGSS ADR1; and also for compact TGSS ADR1 sources above a flux density limit of 200 mJy that had no counterpart in GLEAM. From a total sample of 234 333 GLEAM sources and 275 612 TGSS ADR1 sources in the overlap region between the two surveys, there were 99658 GLEAM sources and 38 978 TGSS ADR sources that passed our flux density cutoff and compactness criteria. Analysis of these sources resulted in three candidate transient sources. Further analysis ruled out two candidates as imaging artefacts. We analyse the third candidate and show it is likely to be real, with a flux density of 182 +/- 26 mJy at 147.5 MHz. This gives a transient surface density of rho = (6.2 +/- 6) x 10-5 deg-2 . We present initial follow-up observations and discuss possible causes for this candidate. The small number of spurious sources from this search demonstrates the high reliability of these two new low-frequency radio catalogues. 2017 Journal Article http://hdl.handle.net/20.500.11937/52622 10.1093/mnras/stw3087 Oxford University Press fulltext |
| spellingShingle | Murphy, T. Kaplan, D. Croft, S. Lynch, C. Callingham, J. Bannister, K. Bell, M. Hurley-Walker, Natasha Hancock, Paul Line, J. Rowlinson, A. Lenc, E. Intema, H. Jagannathan, P. Ekers, Ronald Tingay, Steven Yuan, F. Wolf, C. Onken, C. Dwarakanath, K. For, B. Gaensler, B. Hindson, L. Johnston-Hollitt, M. Kapinska, A. McKinley, B. Morgan, J. Offringa, A. Procopio, P. Staveley-Smith, L. Wayth, Randall Wu, C. Zheng, Q. A search for long-time-scale, low-frequency radio transients |
| title | A search for long-time-scale, low-frequency radio transients |
| title_full | A search for long-time-scale, low-frequency radio transients |
| title_fullStr | A search for long-time-scale, low-frequency radio transients |
| title_full_unstemmed | A search for long-time-scale, low-frequency radio transients |
| title_short | A search for long-time-scale, low-frequency radio transients |
| title_sort | search for long-time-scale, low-frequency radio transients |
| url | http://hdl.handle.net/20.500.11937/52622 |