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标题：Disk masses in the Orion Molecular Cloud-2: distinguishing time and environment ★
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作者：S. E. van Terwisga ; A. Hacar ; E. F. van Dishoeck 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：628
页码：1-14
DOI：10.1051/0004-6361/201935378
语种：English
出版社：EDP Sciences
摘要：Context.The mass evolution of protoplanetary disks is driven by internal processes and by external factors such as photoevaporation. Disentangling these two effects, however, remains difficult.Aims.We measured the dust masses of a sample of 132 disks in the Orion Molecular Cloud 2 (OMC-2) region, and compared them to externally photoevaporated disks in the Trapezium cluster, and to disks in nearby low-mass star-forming regions (SFRs). This allowed us to test whether initial disk properties are the same in high- and low-mass SFRs, and enabled a direct measurement of the effect of external photoevaporation on disks.Methods.A ~ 20′ × 4′ mosaic of 3 mm continuum observations from the Atacama Large Millimeter/submillimeter Array (ALMA) was used to measure the fluxes of 132 disks and 35 protostars >0.5 pc away from the Trapezium. We identify and characterize a sample of 34 point sources not included in theSpitzercatalog on which the sample is based.Results.Of the disks, 37 (28%) are detected, and have masses ranging from 7−270M⊕. The detection rate for protostars is higher (69%). Disks near the Trapezium are found to be less massive by a factor 0.18−0.11+0.18, implying a mass loss rate of 8 × 10−8M⊙yr−1.Conclusions.Our observations allow us to distinguish the impact of time and environment on disk evolution in a single SFR. The disk mass distribution in OMC-2 is statistically indistinguishable from that in nearby low-mass SFRs like Lupus and Taurus. We conclude that age is the main factor that determines the evolution of these disks. This result is robust with respect to assumptions of dust temperature, sample incompleteness, and biases. The difference between the OMC-2 and Trapezium cluster samples is consistent with mass loss driven by far-ultraviolet radiation near the Trapezium. Taken together, this implies that in isolation disk formation and evolution proceed similarly, regardless of cloud mass.
关键词：Key wordsenstars: pre-main sequenceprotoplanetary diskstechniques: interferometric