文章基本信息

标题：Discovery of a sub-Keplerian disk with jet around a 20 M ⊙ young star
其他标题：ALMA observations of G023.01–00.41
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作者：A. Sanna ; A. Kölligan ; L. Moscadelli 等
期刊名称：Astronomy & Astrophysics
印刷版ISSN：0004-6361
电子版ISSN：1432-0746
出版年度：2019
卷号：623
DOI：10.1051/0004-6361/201833411
语种：English
出版社：EDP Sciences
摘要：It is well established that solar-mass stars gain mass via disk accretion, until the mass reservoir of the disk is exhausted and dispersed, or condenses into planetesimals. Accretion disks are intimately coupled with mass ejection via polar cavities in the form of jets and less collimated winds, which allow mass accretion through the disk by removing a substantial fraction of its angular momentum. Whether disk accretion is the mechanism leading to the formation of stars with much higher masses is still unclear. Here, we are able to build a comprehensive picture of the formation of an O-type star by directly imaging a molecular disk, which rotates and undergoes infall around the central star, and drives a molecular jet that arises from the inner disk regions. The accretion disk is truncated between 2000 and 3000 au, it has a mass of about a tenth of the central star mass, and is infalling towards the central star at a high rate (6 × 10−4M⊙yr−1), so as to build up a very massive object. These findings, obtained with the Atacama Large Millimeter/submillimeter Array at 700 au resolution, provide observational proof that young massive stars can form via disk accretion much like solar-mass stars.
关键词：enstars: formationtechniques: high angular resolutionstars: massiveISM: kinematics and dynamics