Studying the structure and dynamics in face-on high mass accretion systems by ALMA

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K17613
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Astronomy
• Research Institution: Yamaguchi University (2016-2017); National Astronomical Observatory of Japan (2015)
• Principal Investigator: Motogi Kazuhito 山口大学, 大学院創成科学研究科, 助教(テニュアトラック) (10722803)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 大質量星形成 / 電波干渉計 / ジェット/アウトフロー / 降着円盤

Outline of Final Research Achievements

This research intend to search and resolve the face-on high mass protostars, that are suitable target for direct imaging of the innermost accretion disk. We first detected five candidate of such face-on object by using the ATCA. We, next, performed a pilot-imaging observation using the ALMA long baseline towards the high mass protostellar object G353.273+0.641, which is the best candidate of a face-on object found in our ATCA survey. We successfully resolved compact accretion disk of 250 AU radius. This is the first spatially resolved view of the high mass accretion system in nearly face-on geometry. The disk showed highly anisotropic distribution of a surface density. Such a structure probably reflects the gravitational instability caused by mass accumulation via accretion flow from a surrounding molecular envelope found by CH3OH lines. This is the first detection of such a highly self-gravitating disk system in high mass star-formation.

Free Research Field

電波天文学