Detailed modeling of dust distribution in the disk of HD?142527
Detailed modeling of dust distribution in the disk of HD?142527
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HD盘中灰尘分布的详细建模？142527
DOI：
10.1093/pasj/psx007
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发表时间：
2017
影响因子：
2.3
通讯作者：
Momose Munetake
中科院分区：
文献类型：
--
作者：
Soon Kang-Lou;Hanawa Tomoyuki;Muto Takayuki;Tsukagoshi Takashi;Momose Munetake
利用阿尔马第0周观测到的890 μ m连续谱观测资料，研究了HD 142527附近新月盘中的尘埃分布。该图被划分为18个方位角扇区，每个扇区的径向强度分布与一个二维磁盘模型再现。我们的模型考虑了散射和倾斜的磁盘以及方位角的强度依赖。当尘埃被假定为具有传统的成分和最大尺寸为1毫米时，西北地区（-351 °）无法再现。这是因为模型强度变得不敏感的表面密度的增加，由于严重的自散射，达到其上限远低于观察到的强度。天花板取决于位置角。当散射不透明度减少了10倍时，强度分布在所有扇区中成功地再现，包括西北区域中的那些扇区。最佳拟合模型参数依赖于南部地区的散射不透明度，光盘是光学薄。尘埃面密度的对比度约为40，远小于常规不透明度的值（70 - 130）。这些结果有力地表明，由于某种原因，至少在西北地区，海平面比所考虑的要低。
We investigate the dust distribution in the crescent disk around HD 142527 based on the continuum emission at 890 μm obtained by ALMA Cycle 0. The map is divided into 18 azimuthal sectors, and the radial intensity profile in each sector is reproduced with a two-dimensional disk model. Our model takes account of scattering and inclination of the disk as well as the azimuthal dependence in intensity. When the dust is assumed to have the conventional composition and a maximum size of 1 mm, the northwestern region (–351°) cannot be reproduced. This is because the model intensity becomes insensitive to the increase in surface density due to heavy self-scattering, reaching its ceiling much lower than the observed intensity. The ceiling depends on the position angle,. When the scattering opacity is reduced by a factor of 10, the intensity distribution is reproduced successfully in all the sectors, including those in the northwestern region. The best-fitting model parameters depend little on the scattering opacity in the southern region where the disk is optically thin. The contrast ratio of dust surface densities alongis derived to be about 40, much smaller than the value in the case of conventional opacities (70–130). These results strongly suggest that the albedo is lower than that considered for some reason, at least in the northwestern region.