文章基本信息

标题：An Unusual Reservoir of Water Emission in the VV CrA A Protoplanetary Disk
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作者：Colette Salyk ; Klaus M. Pontoppidan ; Andrea Banzatti 等
期刊名称：The Astronomical journal
印刷版ISSN：0004-6256
电子版ISSN：1538-3881
出版年度：2022
卷号：164
期号：4
页码：1-25
DOI：10.3847/1538-3881/ac8878
语种：English
出版社：American Institute of Physics
摘要：We present an analysis of an unusual pattern of water vapor emission from the ∼2 Myr old low-mass binary system VV CrA, as observed in IR spectra obtained with VLT-CRIRES, VLT-VISIR, and Spitzer-IRS. Each component of the binary shows emission from water vapor in both the L (∼3 μm) and N (∼12 μm) bands. The N-band and Spitzer spectra are similar to those previously observed from young stars with disks and are consistent with emission from an extended protoplanetary disk. Conversely, the CRIRES L-band data of VV CrA A show an unusual spectrum, which requires the presence of a water reservoir with high temperature (T ≳ 1500 K), column density (NH2O ∼ 3 × 1020 cm−2), and turbulent broadening (v ∼ 10 km s−1) but very small emitting area (A ≲ 0.005 au2). Similarity to previously observed water emission from V1331 Cyg and SVS 13 suggests that the presence of such a reservoir may be linked to evolutionary state, perhaps related to the presence of high accretion rates or winds. While the inner disk may harbor such a reservoir, simple Keplerian models do not match well with emitting line shapes, and alternative velocity fields must be considered. We also present a new idea, that the unusual emission could arise in a circumplanetary disk, embedded within the larger VV CrA A protoplanetary disk. Additional data are likely required to determine the true physical origin of this unusual spectral pattern.