嵌入盘中的早期行星形成（eDisk）. XXIV：基于可见性分析的盘结构系统研究
Early Planet Formation in Embedded Disks (eDisk). XXIV: Systematic Investigation of Disk Structures based on Visibility Analysis
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中文总结 AI 辅助
本研究针对eDisk样本的23个原恒星盘，通过ALMA观测开展uv平面参数化模型分析，明确早期盘非轴对称性普遍存在、盘半径与恒星质量正相关，且仅少数演化程度高的盘具间隙环结构。
中文摘要 AI 辅助
年轻原恒星盘的尘埃连续谱辐射编码了其质量分布与早期演化的关键信息，但统一的高分辨率对比研究仍较为有限。我们对来自eDisk样本的23个盘（包含19个原恒星系统，其中4个为双星系统）的ALMA Band-6（1.3毫米）观测数据开展了系统的uv平面参数化强度模型分析，所用模型涵盖高斯轮廓、带指数尾的幂律核（PLCT）及非对称延伸结构。高斯模型通常无法复现多数观测盘中存在的中心峰状辐射与延展外结构，而PLCT框架对径向亮度轮廓的描述精度显著提升；纳入方位非对称性后，17个倾斜盘中的15个残差进一步降低，表明早期阶段偏离轴对称性的现象普遍存在。仅L1489 IRS与Oph IRS63两个盘呈现清晰的间隙与环子结构，其余多数盘在本次观测的空间分辨率与灵敏度下表现平滑；这些系统属于样本中演化程度最高的，且未包含平谱源，限制了所探测的演化范围，说明盘演化最早阶段并不普遍存在明显的间隙与环结构。采用基于95% enclosed通量的盘半径统一定义，我们发现盘半径与恒星质量呈正相关，关系为$R_{\rm disk} \boldsymbol{\times} M_{\rm \boldsymbol{\bigstar}}^{1.5 \boldsymbol{\times} 0.1}$，且双星系统中的盘系统性小于孤立原恒星周围的盘。尽管模型可捕捉整体形态与大尺度非对称性，但区分光学厚区域的本征结构与辐射转移效应仍具挑战性。
英文摘要
The dust continuum emission from young protostellar disks encodes key information about their mass distribution and early evolution, yet uniform high-resolution comparative studies remain limited. We present a systematic uv-plane analysis of parametric intensity models applied to ALMA Band-6 (1.3 mm) observations of 23 disks (19 protostellar systems with 4 being in binary) from the eDisk sample, spanning Gaussian profiles to power-law cores with exponential tails (PLCT), including asymmetric extensions. Gaussian models generally fail to reproduce the centrally peaked emission and extended outer structure observed in most disks, whereas the PLCT framework provides a significantly improved description of radial brightness profiles. Incorporating azimuthal asymmetries further reduces residuals in 15 of 17 inclined disks, indicating that departures from axisymmetry are common at early stages. Only two disks, L1489 IRS and Oph IRS63, exhibit clear gap and ring substructures, while most appear smooth at the spatial resolution and sensitivity of our observations. These systems are among the most evolved in the sample, and the absence of flat-spectrum sources limits the evolutionary range probed, {suggesting that the detection of prominent gaps and rings is not common} in the earliest phases of disk evolution. Using a uniform definition of disk radius based on the 95\% enclosed flux, we find a positive correlation with stellar mass, $R_{\rm disk} \propto M_{\star}^{1.5 \pm 0.1}$, with disks in binary systems systematically smaller than those around isolated protostars. While the models capture overall morphology and large-scale asymmetries, distinguishing intrinsic structures from radiative transfer effects in optically thick regions remains challenging.
