The Asymmetric Thermal Emission of the Protoplanetary Disk Surrounding HD 142527 Seen by Subaru/COMICS
The Asymmetric Thermal Emission of the Protoplanetary Disk Surrounding HD 142527 Seen by Subaru/COMICS
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DOI：
10.1086/505597
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发表时间：
2006-06
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影响因子：
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通讯作者：
H. Fujiwara;M. Honda;H. Kataza;T. Yamashita;T. Onaka;M. Fukagawa;Y. Okamoto;T. Miyata;S. Sako;T. Fujiyoshi;I. Sakon
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作者：
H. Fujiwara;M. Honda;H. Kataza;T. Yamashita;T. Onaka;M. Fukagawa;Y. Okamoto;T. Miyata;S. Sako;T. Fujiyoshi;I. Sakon
用Subaru/COMICS获得了赫比格Ae星星HD 142527的18.8和24.5 μm的中红外图像。在两幅图像中，在r = 0.″85处识别出明亮的扩展弧形发射（外盘）以及强中心源（内盘）和r = 0.″6附近的间隙。在MIR中，东侧的热辐射比西侧的热辐射亮得多。根据观测到的扩展发射的颜色和与星星的距离，我们估计尘埃的大小为几微米。由这两幅图像还得到了尘埃温度T和光学厚度τ，东侧为T = 82 ± 1 K，τ = 0.052 ± 0.001，西侧为T = 85 ± 3 K，τ = 0.018 ± 0.001。观察到的亮度不对称性可以归因于发射中红外线的尘埃的光学深度的差异。为了解释目前的观测结果，我们提出了一个倾斜盘模型，其中外盘沿沿着东西方向倾斜，东侧位于远侧，而东侧外盘的内缘直接暴露于我们。所提出的模型可以成功地解释MIR观测以及散射光的近红外图像，其中不对称性在相反的意义上被看到，并且其中前向散射光（近侧-西侧）更亮。
Mid-infrared (MIR) images of the Herbig Ae star HD 142527 were obtained at 18.8 and 24.5 μm with the Subaru/COMICS. Bright extended arclike emission (outer disk) is recognized at r = 0.″85 together with a strong central source (inner disk) and a gap around r = 0.″6 in both images. The thermal emission on the eastern side is much brighter than that on the western side in the MIR. We estimate the dust size to be a few microns from the observed color of the extended emission and the distance from the star. The dust temperature T and the optical depth τ of the MIR-emitting dust are also derived from the two images as T = 82 ± 1 K, τ = 0.052 ± 0.001 for the eastern side and T = 85 ± 3 K, τ = 0.018 ± 0.001 for the western side. The observed asymmetry in the brightness can be attributed to the difference in the optical depth of the MIR-emitting dust. To account for the present observations, we propose an inclined disk model, in which the outer disk is inclined along the east-west direction with the eastern side being on the far side while the inner rim of the outer disk on the eastern side is directly exposed to us. The proposed model can successfully account for the MIR observations as well as the near-infrared images of the scattering light, in which the asymmetry is seen in the opposite sense and in which the forward scattering light (near side-western side) is brighter.