JDISC 调查：I 类/平谱盘的内盘化学及早期卵石漂移的初步证据
The JDISC Survey: Inner Disk Chemistry of Class I/FS Disks and Tentative Evidence for Early Pebble Drift
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中文总结 AI 辅助
利用 JWST MIRI/MRS 对蛇夫座恒星形成区的 I/FS 盘进行化学调查，通过测量和建模表征分子库，与 II 类盘比较，发现相关化学特征及与盘半径关系，符合卵石漂移模型，提供盘化学演化框架。
中文摘要 AI 辅助
我们利用詹姆斯·韦布空间望远镜的中红外仪器/中分辨率光谱仪对 I 类和平谱（I/FS）盘进行了首次化学调查，以蛇夫座恒星形成区的 16 个源为目标。通过经验线光度测量和多组分平板建模，我们对这些年轻系统的分子库进行了表征，并将它们与 12 个类似恒星质量的 II 类盘进行了比较。在倾角\(i < 70^{\circ}\)的 I/FS 源中经常检测到水、HCN、C₂H₂和 CO₂，而边缘系统的发射则明显受到抑制。与 II 类盘相比，I/FS 源显示出冷水（约 200K）质量升高和 CO₂激发温度降低的迹象，尽管尚未达到统计学显著水平。统计分析确定吸积光度是两个演化阶段分子质量的主要相关因素。消除这种依赖性后，冷水和 CO₂质量与毫米尘埃盘半径呈反相关，而热水对盘大小不敏感。这些模式与卵石漂移模型定性一致，该模型预测早期水富集，随后 CO₂输送延迟，表明从贫分子的 0 类源，经过富水的 I/FS 盘，到冷水过剩减少的 II 类盘的演化进程。这项工作为盘化学提供了一个初步的演化框架，需要更大的多区域样本进行确认。
英文摘要
We present the first chemical survey of Class I and Flat-Spectrum (I/FS) disks using JWST MIRI/MRS, targeting sixteen sources in the Ophiuchus star-forming region. Through empirical line luminosity measurements and multi-component slab modeling, we characterize the molecular reservoir of these young systems and compare them to twelve Class II disks of similar stellar mass. Water, HCN, C$_2$H$_2$, and CO$_2$ are frequently detected in I/FS sources with inclinations $i < 70^{\circ}$, whereas edge-on systems show significantly suppressed emission. Compared to Class II disks, I/FS sources show suggestive---though not yet statistically significant---evidence for elevated cold water ($\sim$200\,K) mass and lower CO$_2$ excitation temperatures. Statistical analyses identify accretion luminosity as the primary correlate of molecular mass across both evolutionary stages. Once this dependence is removed, cold water and CO$_2$ masses anti-correlate with mm-dust disk radius, while hot water remains insensitive to disk size. These patterns are qualitatively consistent with pebble drift models that predict early water enrichment followed by delayed CO$_2$ delivery, suggesting an evolutionary progression from molecular-poor Class 0 sources, through water-rich Class I/FS disks, to Class II disks with reduced cold water excess. This work provides an initial evolutionary framework for disk chemistry that requires larger, multi-region samples to confirm.
