Detailed structure of the outer disk around HD 169142 with polarized light in H-band
Detailed structure of the outer disk around HD 169142 with polarized light in H-band
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H波段偏振光HD 169142周围外盘的详细结构
DOI：
10.1093/pasj/psv051
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发表时间：
2015
影响因子：
2.3
通讯作者：
Jun Hashimoto et al.
中科院分区：
文献类型：
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作者：
Munetake Momose;Ayaka Morita;Misato Fukagawa;Takayuki Muto;Taku Takeuchi;Jun Hashimoto et al.
利用Subaru/HiCIAO在h波段偏振强度（PI）下对HD 169142周围的星周盘进行了日冕成像。成功探测到02≤r≤12或29≤r≤174 au范围内尘埃颗粒散射在盘面的发射。PI的方位平均径向分布呈双幂律分布，其中PI的inr= 29 ~ 52 au和r= 81.2 ~ 145 au分别呈−3相关关系。这两个幂律区与过渡区（TZ）平滑相连，表现出明显的间隙inr= 40-70 au。内幂律区域的PI显示出深极小值，其位置似乎与λ = 7 mm的点源一致。这可以看作是TZ中存在原行星的另一个迹象。观察到的PI的径向轮廓是由具有不规则表面密度分布、不规则温度分布或两者结合的最小张开盘再现的。通过简单的模型计算，得出内幂律区（r< 50 au）表面密度损耗因子≥0.16。得到的PI图像在幂律区域外也显示出小尺度的不对称性。这些不对称的可能来源包括外部区域散射表面的波纹，以及内部幂律区域膨胀结构的阴影效应。
Coronagraphic imagery of the circumstellar disk around HD 169142 inH-band polarized intensity (PI) with Subaru/HiCIAO is presented. The emission scattered by dust particles at the disk surface in 02 ≤r≤ 12, or 29 ≤r≤ 174 au, is successfully detected. The azimuthally averaged radial profile of the PI shows a double power-law distribution, in which the PIs inr= 29–52 au andr= 81.2–145 au respectively showr−3dependence. These two power-law regions are connected smoothly with a transition zone (TZ), exhibiting an apparent gap inr= 40–70 au. The PI in the inner power-law region shows a deep minimum whose location seems to coincide with the point source at λ = 7 mm. This can be regarded as another sign of a protoplanet in the TZ. The observed radial profile of the PI is reproduced by a minimally flaring disk with an irregular surface density distribution, an irregular temperature distribution, or with a combination of both. The depletion factor of surface density in the inner power-law region (r< 50 au) is derived to be ≥ 0.16 from a simple model calculation. The obtained PI image also shows small-scale asymmetries in the outer power-law region. Possible origins for these asymmetries include corrugation of the scattering surface in the outer region, and a shadowing effect by a puffed-up structure in the inner power-law region.