JpGU-AGU Joint Meeting 2017

講演情報

[EJ] ポスター発表

セッション記号 P (宇宙惑星科学) » P-PS 惑星科学

[P-PS04] [EJ] アルマによる惑星科学の新展開

2017年5月24日(水) 15:30 〜 17:00 ポスター会場 (国際展示場 7ホール)

コンビーナ:百瀬 宗武(茨城大学理学部)、小林 浩(名古屋大学理学研究科)、下条 圭美(国立天文台チリ観測所)、野村 英子(東京工業大学理学院地球惑星科学系)

[PPS04-P05] ALMA Observation of AB Aur: the Inner Gaseous Spirals Observed inside the Dust Cavity

Tang Ya-Wen2、*武藤 恭之1 (1.工学院大学基礎・教養教育部門、2.Academia Sinica, Institute of Astronomy and Astrophysics)

キーワード:原始惑星系円盤、惑星形成、ALMA

We report the results of ALMA observations of protoplanetary disk surrounding a Herbig Ae star AB Aur. We obtained high-resolution (~ 0.1 asec, corresponding to ~14 AU) images in 12CO (J=2-1) emission and dust continuum at the wavelength of 1.3 mm. The continuum emission shows a ring-like structure with the radius of ~120 AU and the CO gas emission shows (at least) two prominent spiral arm like structures within the dust continuum ring. Gas kinematics is consistent with the Keplerian rotation with the inclination of 23 degrees, and the CO spiral arms appear to be about four times brighter than the surrounding medium. Comparison with near infrared (NIR) polarized intensity image (Hashimoto et al. 2011) shows that both CO and NIR images show similar pattern, with NIR polarized emission (scattered light from the central star) locating slightly closer to the central star.

One possible scenario to explain the observed morphology of dust and gas is the disturbances by (an) unseen companion(s). A massive planet at approximately 80 AU from the central star may explain the both spiral structures in gas and dust ring. It is known from near infrared imaging observations that the disk morphology in the outer part of the disk does not change over 5.8 year period. The companion at this radius is far enough from the central star so that the patterns that the companion induces do not change very much. However, this 80 AU companion only does not explain all the morphology. Additional companion at inner radii (which is inaccessible with near infrared imaging observations about a decade ago) or disk warp could be responsible for inner disk structures.

This presentation is based on Tang et al. (2017), which is submitted to AAS Journals.