Polarization morphology of SiO masers in the circumstellar envelope of the asymptotic giant branch star R Cassiopeiae
Polarization morphology of SiO masers in the circumstellar envelope of the asymptotic giant branch star R Cassiopeiae
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渐近巨星分支星 R Cassiopeiae 星周包层 SiO 脉泽的偏振形貌
DOI：
10.1093/mnras/stt242
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发表时间：
2013
影响因子：
4.8
通讯作者：
Assaf K
中科院分区：
文献类型：
--
作者：
Assaf K
Silicon monoxide maser emission has been detected in the circumstellar envelopes of many evolved stars in various vibrationally-excited rotational transitions. It is considered a good tracer of the wind dynamics close to the photosphere of the star. We have investigated the polarization morphology in the circumstellar envelope of an AGB star, R Cas. We mapped the linear and circular polarization of SiO masers in the v=1, J=1-0 transition. The linear polarization is typically a few tens of percent while the circular polarization is a few percent. The fractional polarization tends to be higher for emission of lower total intensity. We found that, in some isolated features the fractional linear polarization appears to exceed 100%. We found the Faraday rotation is not negligible but is ~15 deg., which could produce small scale structure in polarized emission whilst total intensity is smoother and partly resolved out. The polarization angles vary considerably from feature to feature but there is a tendency to favour the directions parallel or perpendicular to the radial direction with respect to the star. In some features, the polarization angle abruptly flips 90 deg. We found that our data are in the regime where the model of Goldreich et al (1973) can be applied and the polarization angle flip is caused when the magnetic field is at close to 55 deg. to the line of sight. The polarization angle configuration is consistent with a radial magnetic field although other configurations are not excluded.
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DOI：
10.1111/j.1365-2966.2011.18629.x
发表时间：
2011-05
期刊：
arXiv: Astrophysics of Galaxies
影响因子：
--
作者：
K. Assaf;P. Diamond;A. Richards;M. Gray
通讯作者：
K. Assaf;P. Diamond;A. Richards;M. Gray
DOI：
10.1086/151852
发表时间：
1973
期刊：
The Astrophysical Journal
影响因子：
--
作者：
P. Goldreich;D. Keeley;J. Kwan
通讯作者：
J. Kwan
350 MHz 银河偏振射电背景中的结构特征
DOI：
--
发表时间：
2003
期刊：
影响因子：
--
作者：
M. Haverkorn;P. Katgert;A. G. D. B. Leiden;Netherlands.;Astron
通讯作者：
Astron
偏振周星SiO脉泽发射中π/2的电矢量旋转
DOI：
--
发表时间：
2011
期刊：
影响因子：
--
作者：
A. Kemball;P. Diamond;L. Richter;I. Gonidakis;R. Xue
通讯作者：
R. Xue
通过 SiO 微波激射观测得到的强度相关的圆偏振和星周磁场
DOI：
--
发表时间：
1994
期刊：
影响因子：
--
作者：
G. Nedoluha;W. D. Watson
通讯作者：
W. D. Watson