Probing relationship between young planet and protoplanetary disk by ALMA

2018 Fiscal Year Final Research Report

• Project/Area Number: 17K14258
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Astronomy
• Research Institution: National Astronomical Observatory of Japan
• Principal Investigator: Hashimoto Jun 国立天文台, 光赤外研究部, 特任助教 (20588610)
• Research Collaborator: Muto Takayuki ; Konishi Mihoko
• Project Period (FY): 2017-04-01 – 2019-03-31
• Keywords: 原始惑星系円盤 / 光赤外天文学 / 電波天文学

Outline of Final Research Achievements

The purpose of this research project is to investigate young forming planets by analyzing the spacial distributions of dust grains and gas in the protoplanetary disks, and the circumplanetary disks around them with ALMA. Though fine structures in dust disks have been obtained by this research, I failed to detect any circumplanetary disks and planets potentially inducing these fine structures. I also attempted to estimate the mass of planets by analyzing the gap structures in the gas disks; however, no gap structure can be found in the gas disks. On the other hand, both a potential increase of the velocity dispersion in the gas and a warped inner gas disk toward an outer disk possibly induced by planet-disk interaction has been found in this research project.

Free Research Field

天文学

Academic Significance and Societal Importance of the Research Achievements

若い惑星（年齢100万年程度）の直接撮像は系外惑星の初期空間分布を明らかにする上で重要である。しかし若い中心星が明るすぎるため、直接撮像の成功例は極めて限られている。その代替手法として、惑星が形成母体の原始惑星系円盤に埋もれている際に生じるギャップ構造に着目して系外惑星の軌道半径や質量を見積もる方法が考案されている。本研究ではそれら間接手法に加え、惑星の軌道や質量に制限を与えるガスの速度分散や速度構造のケプラー回転からのズレを検出した。これら手法を用いることで、系外惑星の空間分布を間接的に明らかにすることができると考えられるため、学術的意義は大きい。