تقرير
Polarisation Observations of H$_{2}$O $J_{K_{-1}K_{1}} = 5_{32} - 4_{41}$ 620.701 GHz Maser Emission with Herschel/HIFI in Orion KL
| العنوان: | Polarisation Observations of H$_{2}$O $J_{K_{-1}K_{1}} = 5_{32} - 4_{41}$ 620.701 GHz Maser Emission with Herschel/HIFI in Orion KL |
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| المؤلفون: | Jones, S. C., Houde, M., Harwit, M., Kidger, M., Kraus, A., McCoey, C., Marston, A., Melnick, G., Menten, K. M., Morris, P., Teyssier, D., Tolls, V. |
| المصدر: | A&A 567, A31 (2014) |
| سنة النشر: | 2014 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Astrophysics of Galaxies |
| الوصف: | Context. The high intensities and narrow bandwidths exhibited by some astronomical masers make them ideal tools for studying star-forming giant molecular clouds. The water maser transition $J_{K_{-1}K_{1}}=5_{32}-4_{41}$ at 620.701 GHz can only be observed from above Earth's strongly absorbing atmosphere; its emission has recently been detected from space. Aims. We sought to further characterize the star-forming environment of Orion KL by investigating the linear polarisation of a source emitting a narrow 620.701 GHz maser feature with the heterodyne spectrometer HIFI on board the Herschel Space Observatory. Methods. High-resolution spectral datasets were collected over a thirteen month period beginning in 2011 March, to establish not only the linear polarisation but also the temporal variability of the source. Results. Within a $3\sigma$ uncertainty, no polarisation was detected to an upper limit of approximately 2%. These results are compared with coeval linear polarisation measurements of the 22.235 GHz $J_{K_{-1}K_{1}}=6_{16}-5_{23}$ maser line from the Effelsberg 100-m radio telescope, typically a much stronger maser transition. Although strongly polarised emission is observed for one component of the 22.235 GHz maser at 7.2 km s$^{-1}$, a weaker component at the same velocity as the 620.701 GHz maser at 11.7 km s$^{-1}$ is much less polarised. Comment: Accepted for publication in A&A |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1051/0004-6361/201323267 |
| URL الوصول: | http://arxiv.org/abs/1406.3841 |
| رقم الأكسشن: | edsarx.1406.3841 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1051/0004-6361/201323267 |
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