论文标题
原始多系统的运动学分析：测量原恒星质量并评估L1448 IRS3B和L1448 IRS3A磁盘中的重力不稳定性
Kinematic Analysis of a Protostellar Multiple System: Measuring the Protostar Masses and Assessing Gravitational Instability in the Disks of L1448 IRS3B and L1448 IRS3A
论文作者
论文摘要
我们提出了新的Atacama大毫米/亚毫米阵列（ALMA）观察结果，该观测值（230〜Au分离）三重原色系统L1448 IRS3B，\ contbeam〜分辨率为879〜 \ micron。周围磁盘内的螺旋臂结构在粉尘连续沿IRS3B的粉尘连续中得到很好的解析，我们检测到已知的宽（2300〜AU）伴侣IRS3A，也可以解决可能的螺旋子结构。使用密集的气体示踪剂，C17O，H13CO $+$和H13CN，我们解决了IRS3B中的圆周磁盘和IRS3A周围的磁盘的开普勒旋转。 Furthermore, we use the molecular line kinematic data and radiative transfer modeling of the molecular line emission to confirm that the disks are in Keplerian rotation with fitted masses of $1.19^{+0.13}_{-0.07}$ for IRS3B-ab, $1.51^{+0.06}_{-0.07}$~Msun for IRS3A, and将上限的上限放在第三纪IRS3B-C 0.2〜MSUN的中心质量上。我们测量IRS3B碎片盘的质量为0.29〜MSUN，从周围磁盘的尘埃连续发射，并估计IRS3B-C周围的团块的质量为0.07〜MSUN。我们还发现IRS3A周围的磁盘的质量为0.04〜MSUN。通过分析toomre〜q参数，我们发现IRS3A Internelar磁盘在重力上是稳定的（Q $> $ 5），而IRS3B磁盘与半径200-500〜AU之间的重力不稳定磁盘（Q $ <$ 1）保持一致。这与螺旋臂和三级伴侣IRS3B-C的位置相吻合，这支持了以下假设：IRS3B-C是通过重力不稳定磁盘的碎片原位形成的。
We present new Atacama Large Millimeter/submillimeter Array (ALMA) observations towards a compact (230~au separation) triple protostar system, L1448 IRS3B, at 879~\micron with \contbeam~resolution. Spiral arm structure within the circum-multiple disk is well resolved in dust continuum toward IRS3B, and we detect the known wide (2300~au) companion, IRS3A, also resolving possible spiral substructure. Using dense gas tracers, C17O, H13CO$+$, and H13CN, we resolve the Keplerian rotation for both the circum-triple disk in IRS3B and the disk around IRS3A. Furthermore, we use the molecular line kinematic data and radiative transfer modeling of the molecular line emission to confirm that the disks are in Keplerian rotation with fitted masses of $1.19^{+0.13}_{-0.07}$ for IRS3B-ab, $1.51^{+0.06}_{-0.07}$~Msun for IRS3A, and place an upper limit on the central protostar mass for the tertiary IRS3B-c of 0.2~Msun. We measure the mass of the fragmenting disk of IRS3B to be 0.29~Msun from the dust continuum emission of the circum-multiple disk and estimate the mass of the clump surrounding IRS3B-c to be 0.07~Msun. We also find that the disk around IRS3A has a mass of 0.04~Msun. By analyzing the Toomre~Q parameter, we find the IRS3A circumstellar disk is gravitationally stable (Q$>$5), while the IRS3B disk is consistent with a gravitationally unstable disk (Q$<$1) between the radii 200-500~au. This coincides with the location of the spiral arms and the tertiary companion IRS3B-c, supporting the hypothesis that IRS3B-c was formed in situ via fragmentation of a gravitationally unstable disk.
