AI 中文总结
本研究针对金牛座26个原恒星盘系统，利用ALMA与VLA观测及CO同位素体建模，测量了不同波段下的尘埃、气体质量与盘尺寸，明确了金牛座原恒星盘的相关特性及气体尘埃比范围。
AI 中文摘要
包层嵌入的原恒星盘代表了原行星盘演化的最早阶段，但其质量和大小难以测量，因为盘的发射与包层纠缠在一起。我们利用ALMA 7波段（345 GHz；~0.3''）和VLA Ka波段（33 GHz；~0.2''）的连续谱观测，结合分子线数据，分析了金牛座的26个原恒星盘系统，以约束盘气体质量。在345 GHz下，中值流量密度、尘埃质量和半径分别为71 mJy、5.5 M⊕和28 AU，68%范围为54-107 mJy、3.9-9.4 M⊕、25-39 AU；在33 GHz下，对应中值为0.43 mJy、39 M⊕、32 AU，范围为0.41-0.80 mJy、34-52 M⊕、29-33 AU。金牛座I类盘比猎户座的盘更暗、质量更小，与英仙座I类盘相当，但比英仙座0类盘暗，且比蛇夫座的盘更亮、质量更大。在金牛座内部，0/I类盘在两个频率下都比II类盘更亮，尽管在345 GHz下推断的尘埃质量相当，在33 GHz下略高。对CO同位素体发射的辐射传输建模得出中值气体质量为6.7×10⁻⁴ M☉。由此推断的CO气体与尘埃质量比范围广泛，均值为147±75，中值为26，16-84百分位范围为8-147。该分布低端与金牛座II类群体重叠，高端则包含类似ISM或更高的值，包括AGE-PRO蛇夫座0/I类群体。
英文摘要
Envelope-embedded protostellar disks represent the earliest stage of protoplanetary disk evolution, but their masses and sizes are difficult to measure because disk emission is entangled with the envelope. We analyze 26 protostellar disk systems in Taurus using ALMA Band 7 (345 GHz; ~0.3'') and VLA Ka-band (33 GHz; ~0.2'') continuum observations, together with molecular-line data to constrain disk gas masses. At 345 GHz, the median flux density, dust mass, and radius are 71 mJy, 5.5 M_Mearth, and 28 AU, with 68% ranges of 54-107 mJy, 3.9-9.4 M_Mearth, and 25-39 AU. At 33 GHz, the corresponding medians are 0.43 mJy, 39 M_Mearth, and 32 AU, with ranges of 0.41-0.80 mJy, 34-52 M_Mearth, and 29-33 AU. Taurus Class I disks are fainter and less massive than those in Orion, comparable to Perseus Class I disks but fainter than Perseus Class 0 disks, and brighter and more massive than those in Ophiuchus. Within Taurus, Class 0/I disks are brighter than Class II disks at both frequencies, although their inferred dust masses are comparable at 345 GHz and slightly higher at 33 GHz. Radiative-transfer modeling of CO isotopologue emission yields a median gas mass of 6.7 x 10^-4 M_Msun. The resulting CO-inferred gas-to-dust ratios span a broad range, with a mean of 147 +/- 75, a median of 26, and a 16th-84th percentile range of 8-147. This distribution overlaps the Taurus Class II population at the low end and ISM-like or higher values, including the AGE-PRO Ophiuchus Class 0/I population, at the high end.
Comments31 pages, 11 Figures, Figure 10 and 11 are figure sets with 28 figures and 58 figures respectively
