论文标题
A级Protostar L1489 IRS周围的磁盘结构由Alma揭示：扭曲的磁盘系统
Disk structure around the Class I protostar L1489 IRS revealed by ALMA: a warped disk system
论文作者
论文摘要
我们已经观察到I级Protostar L1489 IRS，带有第6段中的Atacama毫米/亚毫米阵列（ALMA）。C$^{18} $ o $ $ $ J = $ 2-1线排放显示，由于旋转而在同一方向上呈平面和非轴对称结构，并且由于旋转而在同一方向上。我们发现c $^{18} $ o发射显示倾角的半径〜200-300 au，而1.3毫米的连续发射则平稳地延伸至r〜400 au。在c $^{18} $ o的半径上，外部的旋转轴似乎与内部成分的旋转轴倾斜了约15度。相对于C $^{18} $ o的内部组件和外部组件都展示了$ r^{ - 0.5} $开普勒旋转配置文件，直到r〜600 au。这些结果不仅表明开普勒磁盘可扩展到〜600 au，而且磁盘已被扭曲。我们构建了一个在开普勒速度旋转的三维扭曲磁盘模型，并证明扭曲的磁盘模型在速度通道图和PV图中重现了观察到的主要特征。这种扭曲的磁盘系统可以通过未对准的信封中的大量积聚形成。我们还基于I和II类资源之间的磁盘半径和质量的比较讨论了可能的磁盘演化方案。
We have observed the Class I protostar L1489 IRS with the Atacama Millimeter/submillimeter Array (ALMA) in Band 6. The C$^{18}$O $J=$2-1 line emission shows flattened and non-axisymmetric structures in the same direction as its velocity gradient due to rotation. We discovered that the C$^{18}$O emission shows dips at a radius of ~200-300 au while the 1.3 mm continuum emission extends smoothly up to r~400 au. At the radius of the C$^{18}$O dips, the rotational axis of the outer portion appears to be tilted by ~15 degrees from that of the inner component. Both the inner and outer components with respect to the C$^{18}$O dips exhibit the $r^{-0.5}$ Keplerian rotation profiles until r~600 au. These results not only indicate that a Keplerian disk extends up to ~600 au but also that the disk is warped. We constructed a three dimensional warped disk model rotating at the Keplerian velocity, and demonstrated that the warped disk model reproduces main observed features in the velocity channel maps and the PV diagrams. Such a warped disk system can form by mass accretion from a misaligned envelope. We also discuss a possible disk evolution scenario based on comparisons of disk radii and masses between Class I and Class II sources.
