Polarization Observations of the Anomalous Microwave Emission in the Perseus Molecular Complex with the COSMOSOMAS Experiment
Polarization Observations of the Anomalous Microwave Emission in the Perseus Molecular Complex with the COSMOSOMAS Experiment
复制标题
用 COSMOSOMAS 实验对英仙座分子复合物中反常微波发射的偏振观测
DOI：
10.1086/506254
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
R. Hoyland
中科院分区：
文献类型：
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作者：
E. Battistelli;E. Battistelli;R. Rebolo;J. Rubiño;S. Hildebrandt;R. Watson;R. Watson;Carlos M. Gutiérrez;R. Hoyland
Watson等人在英仙座分子复合物中探测到的异常微波发射已经通过COSMOSOMAS实验在11 GHz下通过双正交偏振观测到。Stokes U和Q图的分辨率为~0。°9为30°× 30°区域，包括英仙座分子复合物。微弱偏振发射已经被测量；我们发现Q = -0.2%±1.0%和U = -3.4%，两者都在95%的置信水平上，系统不确定度估计低于1%，这是通过使用我们地图中的非极化源作为零假设对仪器性能进行测试确定的。得到的总极化能级为Π = 3.4%。这是对异常微波发射源极化特性的第一个限制。低水平的极化似乎表明，在英仙座分子复合体中负责这种发射的粒子在整个区域内并没有明显地排列在一个共同的方向上，这是发射粒子高度结构对称性或低强度磁场的结果。我们的弱探测完全符合电偶极子发射和共振弛豫在这个频率上的预测。
The anomalous microwave emission detected in the Perseus molecular complex by Watson et al. has been observed at 11 GHz through dual orthogonal polarizations with the COSMOSOMAS experiment. Stokes U and Q maps were obtained at a resolution of ~0.°9 for a 30° × 30° region including the Perseus molecular complex. Faint polarized emission has been measured; we find Q = -0.2% ± 1.0% and U = -3.4%, both at the 95% confidence level, with a systematic uncertainty estimated to be lower than 1% determined from tests of the instrumental performance using unpolarized sources in our map as null hypothesis. The resulting total polarization level is Π = 3.4%. These are the first constraints on the polarization properties of an anomalous microwave emission source. The low level of polarization seems to indicate that the particles responsible for this emission in the Perseus molecular complex are not significantly aligned in a common direction over the whole region, as a consequence of either a high structural symmetry in the emitting particle or a low-intensity magnetic field. Our weak detection is fully consistent with predictions from electric dipole emission and resonance relaxation at this frequency.