Infrared polarimetry of Mrk 231: scattering off hot dust grains in the central core
Infrared polarimetry of Mrk 231: scattering off hot dust grains in the central core
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Mrk 231 的红外偏振测量：中心核心中热尘埃颗粒的散射
DOI：
10.1093/mnras/stw2491
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发表时间：
2017
影响因子：
4.8
通讯作者：
Telesco
中科院分区：
文献类型：
--
作者：
Lopez-Rodriguez;E.;Packham;C.;Jones;T. J.;Siebenmorgen;R.;Roche;P. F.;Levenson;N. A.;Alonso-Herrero;A.;Perlman;E.;Ichikawa;K.;Ramos Almeida;C.;Gonzalez-Martin;O.;Nikutta;R.;Martinez-Paredez;M.;Shenoy;D.;Gordon;M. S.;Telesco
我们在6.5-mMMT上使用MMT-Pol在3.1 μm滤波器中以及在10.4-mGran Telescopio CANARIAS上使用CanariCam在8.7，10.3和11.6 μm滤波器中对Mrk 231进行了高角度（0.17-0.35 arcsec）分辨率成像偏振观测。结合已发表的观测资料，我们编制了1-12 μm总的和极化的核谱能量分布（SED）。在中心400 pc的总通量SED被解释为（1）热（731 ± 4K）尘埃结构，由中央发动机直接照射，位于1.6 ± 0.1pc的极区，（2）光学厚度，围绕中央发动机的一个倾角为48± 23 °的光滑盘状尘埃结构（“环面”）;（3）一个熄灭的（AV= 36 ± 5等）星爆分量。偏振SED从1.2 μm处的0.77 ± 0.14%减小到11.6 μm处的0.31 ± 0.15%，并遵循幂律函数λ = 0.57。偏振角在1-12 μm波长范围内保持恒定（λ 108）。主导的偏振机制被解释为散射小康热尘埃颗粒在pc尺度的极地地区。
We present high-angular (0.17–0.35 arcsec) resolution imaging polarimetric observations of Mrk 231 in the 3.1 μm filter using MMT-Pol on the 6.5-m MMT, and in the 8.7, 10.3, and 11.6 μm filters using CanariCam on the 10.4-m Gran Telescopio CANARIAS. In combination with already published observations, we compile the 1–12 μm total and polarized nuclear spectral energy distribution (SED). The total flux SED in the central 400 pc is explained as the combination of (1) a hot (731 ± 4 K) dusty structure, directly irradiated by the central engine, which is at 1.6 ± 0.1 pc away and attributed to be in the pc-scale polar region, (2) an optically-thick, smooth and disc-like dusty structure (‘torus’) with an inclination of 48± 23surrounding the central engine, and (3) an extinguished (AV= 36 ± 5 mag) starburst component. The polarized SED decreases from 0.77 ± 0.14 per cent at 1.2 μm to 0.31 ± 0.15 per cent at 11.6 μm and follows a power-law function, λ∼0.57. The polarization angle remains constant (∼108) in the 1–12 μm wavelength range. The dominant polarization mechanism is explained as scattering-off hot dust grains in the pc-scale polar regions.