Gravitational instability in a planet-forming disk

• 成果类型: Article
• 署名作者: Speedie, Jessica; Dong, Ruobing; Hall, Cassandra; Longarini, Cristiano; Veronesi, Benedetta; Paneque-Carreno, Teresa; Lodato, Giuseppe; Tang, Ya-Wen; Teague, Richard; Hashimoto, Jun
• 署名单位: University of Victoria; Peking University; University System of Georgia; University of Georgia; University System of Georgia; University of Georgia; University of Milan; University of Cambridge; Universite Claude Bernard Lyon 1; Centre National de la Recherche Scientifique (CNRS); CNRS - National Institute for Earth Sciences & Astronomy (INSU); Ecole Normale Superieure de Lyon (ENS de LYON); Leiden University - Excl LUMC; Leiden University; European Southern Observatory; Academia Sinica - Taiwan; Massachusetts Institute of Technology (MIT); National Institutes of Natural Sciences (NINS) - Japan; Astrobiology Center (ABC); National Institutes of Natural Sciences (NINS) - Japan; National Astronomical Observatory of Japan (NAOJ); Graduate University for Advanced Studies - Japan
• 刊物名称: Nature
• ISSN/ISSBN: 0028-5662
• DOI: 10.1038/s41586-024-07877-0
• 发表日期: 2024-09-05
• 页码: 58-+
• 关键词: herbig ae/be stars; radiative-transfer; ab-aur; accretion; dust; transport; velocity; locality; solar

摘要

The canonical theory for planet formation in circumstellar disks proposes that planets are grown from initially much smaller seeds(1-5). The long-considered alternative theory proposes that giant protoplanets can be formed directly from collapsing fragments of vast spiral arms(6-11) induced by gravitational instability(12-14)-if the disk is gravitationally unstable. For this to be possible, the disk must be massive compared with the central star: a disk-to-star mass ratio of 1:10 is widely held as the rough threshold for triggering gravitational instability, inciting substantial non-Keplerian dynamics and generating prominent spiral arms(15-18). Although estimating disk masses has historically been challenging(19-21), the motion of the gas can reveal the presence of gravitational instability through its effect on the disk-velocity structure(22-24). Here we present kinematic evidence of gravitational instability in the disk around AB Aurigae, using deep observations of (CO)-C-13 and (CO)-O-18 line emission with the Atacama Large Millimeter/submillimeter Array (ALMA). The observed kinematic signals strongly resemble predictions from simulations and analytic modelling. From quantitative comparisons, we infer a disk mass of up to a third of the stellar mass enclosed within 1 '' to 5 '' on the sky.