第一个静压堆芯候选体Cha-MMS1的动力学状态
The dynamical state of the First Hydrostatic Core Candidate Cha-MMS1
摘要：
第一流体静力学核心候选者的观测，理论上预测星前和原恒星阶段之间的进化联系，对于探测恒星形成的最早阶段至关重要。我们的目标是确定第一流体静力学核心候选人Cha-MMS 1的动力学状态。我们用APEX和Mopra望远镜观察了Cha-MMS 1的各种转变。利用辐射转移程序对分子发射进行建模，以导出包络运动学上的约束。我们得出的内部光度为0.08 - 0.18 Lsol。垂直于Cha-MMS 1所嵌入的暗条，发现在0.08秒差距上的平均速度梯度为3.1（0.1）km/s/pc。梯度在外部和最内部的2000 - 4000 AU是平坦的。这些特征表明，固体旋转超过4000 AU和更慢，差异旋转超过8000 AU。最里面部分的平坦梯度的起源尚不清楚。在HCO+ 3-2和CS 2-1中检测到经典的下落信号。辐射转移模拟表明，在包层的外部，有一个均匀的下落速度。以r^（-0.5）为尺度的下落速度场与r < 9000 AU的数据一致。在r > 3300 AU时，入射速度为0.1 - 0.2 km/s;在r < 3300 AU时，入射速度为0.04 - 0.6 km/s。Cha-MMS 1的内部光度和包层内的速度场与MHD模拟对第一核相的预测是一致的。没有证据表明Cha-MMS 1产生了快速、大规模的外流，但高密度示踪剂CS 5-4、CO 6-5和CO 7-6的过量排放表明内核存在高速物质。它的内部亮度排除了Cha-MMS 1是星前核心的可能性。它的包层的运动学性质与Cha-MMS 1是第一个核心候选者或非常年轻的0级原恒星是一致的。（节略）。
英文摘要：
Observations of First Hydrostatic Core candidates, a theoretically predicted evolutionary link between the prestellar and protostellar phases, are vital for probing the earliest phases of star formation. We aim to determine the dynamical state of the First Hydrostatic Core candidate Cha-MMS1. We observed Cha-MMS1 in various transitions with the APEX and Mopra telescopes. The molecular emission was modeled with a radiative transfer code to derive constraints on the envelope kinematics. We derive an internal luminosity of 0.08 - 0.18 Lsol. An average velocity gradient of 3.1(0.1) km/s/pc over 0.08 pc is found perpendicular to the filament in which Cha-MMS1 is embedded. The gradient is flatter in the outer parts and at the innermost 2000 - 4000 AU. These features suggest solid-body rotation beyond 4000 AU and slower, differential rotation beyond 8000 AU. The origin of the flatter gradient in the innermost parts is unclear. The classical infall signature is detected in HCO+ 3-2 and CS 2-1. The radiative transfer modeling indicates a uniform infall velocity in the outer parts of the envelope. An infall velocity field scaling with r^(-0.5) is consistent with the data for r < 9000 AU. The infall velocities are 0.1 - 0.2 km/s at r > 3300 AU and 0.04 - 0.6 km/s at r < 3300 AU. Both the internal luminosity of Cha-MMS1 and the infall velocity field in its envelope are consistent with predictions of MHD simulations for the first core phase. There is no evidence for a fast, large-scale outflow stemming from Cha-MMS1 but excess emission from the high-density tracers CS 5-4, CO 6-5, and CO 7-6 suggests the presence of higher-velocity material at the inner core. Its internal luminosity excludes Cha-MMS1 being a prestellar core. The kinematical properties of its envelope are consistent with Cha-MMS1 being a first core candidate or a very young Class 0 protostar.(abridged).
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
