SPLASH: the Southern Parkes Large-Area Survey in Hydroxyl – first science from the pilot region
The Southern Parkes Large-Area Survey in Hydroxyl (SPLASH) is a sensitive, unbiased, and fully sampled survey of the southern Galactic plane and Galactic Centre in all four ground-state transitions of the hydroxyl (OH) radical. The survey provides a deep census of 1612-, 1665-, 1667-, and 1720-MHz O...
| Main Authors: | , , , , , , , , , , , , , , , , , , , , , , |
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| Format: | Journal Article |
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Oxford University Press
2014
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| Subjects: | |
| Online Access: | http://hdl.handle.net/20.500.11937/23538 |
| _version_ | 1848751179005165568 |
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| author | Dawson, J. Walsh, Andrew Jones, P. Breen, S. Cunningham, M. Lowe, V. Jones, C. Purcell, C. Caswell, J. Carretti, E. McClure-Griffiths, N. Ellingsen, S. Green, J. Gómez, J. Krishnan, V. Dickey, J. Imai, H. Gibson, S. Hennebelle, P. Lo, N. Hayakawa, T. Fukui, Y. Mizuno, A. |
| author_facet | Dawson, J. Walsh, Andrew Jones, P. Breen, S. Cunningham, M. Lowe, V. Jones, C. Purcell, C. Caswell, J. Carretti, E. McClure-Griffiths, N. Ellingsen, S. Green, J. Gómez, J. Krishnan, V. Dickey, J. Imai, H. Gibson, S. Hennebelle, P. Lo, N. Hayakawa, T. Fukui, Y. Mizuno, A. |
| author_sort | Dawson, J. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | The Southern Parkes Large-Area Survey in Hydroxyl (SPLASH) is a sensitive, unbiased, and fully sampled survey of the southern Galactic plane and Galactic Centre in all four ground-state transitions of the hydroxyl (OH) radical. The survey provides a deep census of 1612-, 1665-, 1667-, and 1720-MHz OH absorption and emission from the Galactic interstellar medium, and is also an unbiased search for maser sources in these transitions. We present here first results from the SPLASH pilot region, which covers Galactic longitudes 334° to 344° and latitudes ±2?. Diffuse OH is widely detected in all four transitions, with optical depths that are always small (averaged over the Parkes beam), and with departures from local thermodynamic equilibrium common even in the 1665- and 1667-MHz main lines. To a 3σ sensitivity of ~30 mK, we find no evidence of OH envelopes extending beyond the CO-bright regions of molecular cloud complexes, and conclude that the similarity of the OH excitation temperature and the level of the continuum background is at least partly responsible for this. We detect masers and maser candidates in all four transitions, approximately 50 per cent of which are new detections. This implies that SPLASH will produce a substantial increase in the known population of ground-state OH masers in the southern Galactic plane. |
| first_indexed | 2025-11-14T07:48:36Z |
| format | Journal Article |
| id | curtin-20.500.11937-23538 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T07:48:36Z |
| publishDate | 2014 |
| publisher | Oxford University Press |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-235382017-09-13T13:59:02Z SPLASH: the Southern Parkes Large-Area Survey in Hydroxyl – first science from the pilot region Dawson, J. Walsh, Andrew Jones, P. Breen, S. Cunningham, M. Lowe, V. Jones, C. Purcell, C. Caswell, J. Carretti, E. McClure-Griffiths, N. Ellingsen, S. Green, J. Gómez, J. Krishnan, V. Dickey, J. Imai, H. Gibson, S. Hennebelle, P. Lo, N. Hayakawa, T. Fukui, Y. Mizuno, A. Galaxy: disc ISM: molecules masers surveys radio lines: ISM The Southern Parkes Large-Area Survey in Hydroxyl (SPLASH) is a sensitive, unbiased, and fully sampled survey of the southern Galactic plane and Galactic Centre in all four ground-state transitions of the hydroxyl (OH) radical. The survey provides a deep census of 1612-, 1665-, 1667-, and 1720-MHz OH absorption and emission from the Galactic interstellar medium, and is also an unbiased search for maser sources in these transitions. We present here first results from the SPLASH pilot region, which covers Galactic longitudes 334° to 344° and latitudes ±2?. Diffuse OH is widely detected in all four transitions, with optical depths that are always small (averaged over the Parkes beam), and with departures from local thermodynamic equilibrium common even in the 1665- and 1667-MHz main lines. To a 3σ sensitivity of ~30 mK, we find no evidence of OH envelopes extending beyond the CO-bright regions of molecular cloud complexes, and conclude that the similarity of the OH excitation temperature and the level of the continuum background is at least partly responsible for this. We detect masers and maser candidates in all four transitions, approximately 50 per cent of which are new detections. This implies that SPLASH will produce a substantial increase in the known population of ground-state OH masers in the southern Galactic plane. 2014 Journal Article http://hdl.handle.net/20.500.11937/23538 10.1093/mnras/stu032 Oxford University Press fulltext |
| spellingShingle | Galaxy: disc ISM: molecules masers surveys radio lines: ISM Dawson, J. Walsh, Andrew Jones, P. Breen, S. Cunningham, M. Lowe, V. Jones, C. Purcell, C. Caswell, J. Carretti, E. McClure-Griffiths, N. Ellingsen, S. Green, J. Gómez, J. Krishnan, V. Dickey, J. Imai, H. Gibson, S. Hennebelle, P. Lo, N. Hayakawa, T. Fukui, Y. Mizuno, A. SPLASH: the Southern Parkes Large-Area Survey in Hydroxyl – first science from the pilot region |
| title | SPLASH: the Southern Parkes Large-Area Survey in Hydroxyl – first science from the pilot region |
| title_full | SPLASH: the Southern Parkes Large-Area Survey in Hydroxyl – first science from the pilot region |
| title_fullStr | SPLASH: the Southern Parkes Large-Area Survey in Hydroxyl – first science from the pilot region |
| title_full_unstemmed | SPLASH: the Southern Parkes Large-Area Survey in Hydroxyl – first science from the pilot region |
| title_short | SPLASH: the Southern Parkes Large-Area Survey in Hydroxyl – first science from the pilot region |
| title_sort | splash: the southern parkes large-area survey in hydroxyl – first science from the pilot region |
| topic | Galaxy: disc ISM: molecules masers surveys radio lines: ISM |
| url | http://hdl.handle.net/20.500.11937/23538 |