Polarized Mid-infrared Synchrotron Emission in the Core of Cygnus A
Polarized Mid-infrared Synchrotron Emission in the Core of Cygnus A
复制标题
天鹅座 A 核心的偏振中红外同步加速器发射
DOI：
10.1088/0004-637x/793/2/81
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
C. M. Telesco
中科院分区：
文献类型：
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作者：
E. Lopez-Rodriguez;C. Packham;C. Tadhunter;R. Mason;E. Perlman;A. Alonso-Herrero;C. Ramos Almeida;K. Ichikawa;N. A. Levenson;J. Rodríguez-Espinosa;C. Álvarez;E. A. Ramírez;C. M. Telesco
利用10.4 m大望远镜Canarias上的CanariCam对天鹅座A的8.7 μm和11.6 μm滤光片进行了高角分辨率（100 farcs 4）的中红外偏振观测。在0farcs 38（φ 380pc）孔径下，观察到一个高极化核，其极化度分别为11%±3%和12%±3%，极化位置角分别为27±8和35±8。观测到的偏振通量密度随波长增加而增加的现象与天鹅座A核心附近秒差距尺度喷流的同步辐射一致。根据我们的偏振模型，在8.7 μm和11.6 μm滤光片中，来自秒差距尺度喷流的同步辐射分别占总通量密度的14%和17%。特征温度为220 K的黑体分量占所观测到的MIR总通量密度的> 75%。黑体辐射来自于（1）环面中的尘埃辐射和（2）核区域周围的弥散尘埃辐射的组合，但这两个分量的贡献在这些观测中不能很好地约束。
We present high-angular (∼ 0 farcs 4) resolution mid-infrared (MIR) polarimetric observations in the 8.7 μm and 11.6 μm filters of Cygnus A using CanariCam on the 10.4 m Gran Telescopio CANARIAS. A highly polarized nucleus is observed with a degree of polarization of 11%±3% and 12%±3% and a position angle of polarization of 27±8 and 35±8 in a 0 farcs 38 (∼ 380 pc) aperture for each filter. The observed rising of the polarized flux density with increasing wavelength is consistent with synchrotron radiation from the parsec-scale jet close to the core of Cygnus A. Based on our polarization model, the synchrotron emission from the parsec-scale jet is estimated to be 14% and 17% of the total flux density in the 8.7 μm and 11.6 μm filters, respectively. A blackbody component with a characteristic temperature of 220 K accounts for> 75% of the observed MIR total flux density. The blackbody emission arises from a combination of (1) dust emission in the torus; and (2) diffuse dust emission around the nuclear region, but the contributions of the two components cannot be well-constrained in these observations.