日本地球惑星科学連合2019年大会

講演情報

[J] ポスター発表

セッション記号 P (宇宙惑星科学) » P-CG 宇宙惑星科学複合領域・一般

[P-CG24] アルマによる惑星科学の新展開

2019年5月29日(水) 15:30 〜 17:00 ポスター会場 (幕張メッセ国際展示場 8ホール)

コンビーナ:武藤 恭之(工学院大学 教育推進機構)、百瀬 宗武(茨城大学理学部)、佐川 英夫(京都産業大学理学部)、下条 圭美(国立天文台)

[PCG24-P02] Investigating the gas-to-dust ratio in the protoplanetary disk of HD 142527

*Soon Kang-Lou1百瀬 宗武1武藤 恭之2塚越 崇3片岡 章雅3花輪 知幸4深川 美里3西合 一矢3芝井 広5 (1.茨城大学、2.工学院大学、3.国立天文台、4.千葉大学、5.大阪大学)

キーワード:HD 142527、原始惑星系円盤、ガス・ダスト比

We present the ALMA observations of the 98.5 GHz dust continuum and the 13CO J = 1 – 0 and C18O J = 1 – 0 line emission towards the protoplanetary disk of HD 142527. The 98.5 GHz continuum shows a strong azimuthal-asymmetric distribution similar to the previously reported 336 GHz continuum, and its peak emission at the dust concentrated northern region is optically thin at approximately 8 K. In every position angle, the peak brightness temperature of C18O J = 1 – 0 emission (≦ 25 K) is lower than that of the optically thick 13CO J = 3 – 2 (≈ 36 K), indicating that the C18O is optically thin. We derive the gas and dust surface densities, Σg and Σd, of the disk of HD 142527 by using the ALMA Band 3 and Band 7 observations. In the analyses we assume the local thermodynamic equilibrium and the disk temperature to be the same as the peak brightness temperature of 13CO J = 3 – 2 with continuum emission. We successfully derived the gas-to-dust ratio G/D, defined as Σgd, distribution across the disk. The ratio varies azimuthally, where it is ∼3 and ∼20 in the disk northern and southern regions, respectively. We also found that Σg varies approximately as ∝ Σd0.5, or equivalently G/D ∝ Σd-0.5. In addition, our results show that the peak Σd is located ahead of the peak Σg; if the latter correspond to a vortex of high gas pressure, the results indicate that the dust are trapped ahead of the vortex, which is predicted by theoretical studies.