通过核合并抛物线相遇组装的一颗大质量偏心原双星
An Eccentric Massive Protobinary Assembled via a Core-merger Parabolic Encounter
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中文总结 AI 辅助
通过ALMA、JVLA等多波段观测重建大质量原双星IRAS 07299-1651的三维轨道，发现其高偏心近抛物线轨道及星周盘错位，支持核合并场景，为偏心大质量双星形成提供重要路径。
中文摘要 AI 辅助
大多数大质量恒星形成于双星系统中，这深刻影响了它们随后的演化。然而，这类系统如何形成仍知之甚少，目前提出了几种相互竞争的场景，包括盘碎裂、核碎裂和捕获。因此，确定大质量双星的轨道结构，尤其是在其最早期的嵌入阶段，对于区分这些形成路径至关重要，但直接测量它们的三维运动一直异常困难。在此，我们展示了针对大质量原双星IRAS 07299$-$1651的高分辨率、多历元亚毫米至厘米波段的ALMA和JVLA观测，并辅以JWST和VLT红外成像。我们探测到了双星分量的轨道自行，从而实现了完整的三维轨道重建。结合轨道拟合、多波长连续谱建模、氢复合线运动学以及喷流观测，我们发现最优的轨道解具有高度偏心且接近抛物线的特征，而两个星周盘均与轨道平面强烈错位。这些性质自然地由“核合并”场景所解释，在该场景中，两颗原恒星最初独立形成于原本无界的核中，这些核近期经历了一次近抛物线相遇，产生了当前间距约200 au的偏心双星。这些发现表明，核合并过程可能代表了形成偏心大质量双星的一条重要路径。
英文摘要
Most massive stars form in binary systems, which profoundly influence their subsequent evolution. However, how such systems form remains poorly understood, with several competing scenarios proposed, including disk fragmentation, core fragmentation and capture. Determining the orbital architectures of massive binaries, particularly during their earliest embedded phases, is therefore crucial for distinguishing among these formation pathways, but direct measurements of their three-dimensional motions have remained exceptionally challenging. Here we present high-resolution, multi-epoch sub-millimeter-to-centimeter ALMA and JVLA observations of the massive protobinary IRAS 07299$-$1651, complemented by JWST and VLT infrared imaging. We detect orbital proper motion of the binary components, enabling a full three-dimensional orbital reconstruction. Combining orbital fitting, multi-wavelength continuum modelling, hydrogen recombination line kinematics and jet observations, we find that the preferred orbital solutions are highly eccentric and close to parabolic, while both circumstellar disks are strongly misaligned with the orbital plane. These properties are naturally explained by a ``core-merger'' scenario in which the two protostars originated independently from initially unbound cores that recently underwent a near-parabolic encounter, producing an eccentric binary with a current separation of about 200 au. These findings suggest that the core-merger process may represent an important pathway for forming eccentric massive binaries.
发表机构
- Shanghai Jiao Tong University（上海交通大学）
- Instituto de Astrofísica de Andalucía, CSIC（安达卢西亚天体物理研究所，西班牙高等科学研究委员会）
- Institute of Science Tokyo（东京科学大学）
- California Institute of Technology（加州理工学院）
- Space Science Institute（空间科学研究所）
机构由 AI 辅助整理，请以论文原文为准。
