论文标题
SAO 206462 Protoplanetary磁盘中的螺旋臂模式运动
Spiral Arm Pattern Motion in the SAO 206462 Protoplanetary Disk
论文作者
论文摘要
在十多个原始磁盘中观察到了螺旋臂，但是几乎所有系统的起源都在争论中。螺旋形臂形态的多个上周期监测为区分两种领先的臂形成机制提供了一种动态的方式：伴侣驱动和引力不稳定性诱导，因为这些机制可以预测不同的运动模式。通过分析2015年和2016年在非常大的望远镜（VLT）上使用球形仪器对SAO 206462系统的多上述J波段观测值，我们在极光光中测量了其两个突出的螺旋臂的模式运动。一方面，如果两臂都在共处，则可以由$ 86 _ { - 13}^{+18} $ au在圆形轨道上以$ 86 _ { - 13}^{ - 13}^{+18} $ au驱动，而引力不稳定运动排除在外。另一方面，它们可以由两个行星以$ 120 _ { - 30}^{+30} $ au和$ 49 _ { - 5}^{+6} $ au驱动，提供了暂时的证据（3.0 $σ$），表明两个螺旋都在独立移动。我们在1998年和2005年使用NICMOS仪器在Hubble空间望远镜（HST）上重新还原档案观测的分析可以支持独立的手臂运动，但是包括阴影在内的人工制品可以在HST观察中表现出虚假的手臂运动。我们希望将来的重新观察能够更好地限制SAO 206462螺旋臂的运动机制。
Spiral arms have been observed in more than a dozen protoplanetary disks, yet the origin of nearly all systems is under debate. Multi-epoch monitoring of spiral arm morphology offers a dynamical way in distinguishing two leading arm formation mechanisms: companion-driven, and gravitational instability induction, since these mechanisms predict distinct motion patterns. By analyzing multi-epoch J-band observations of the SAO 206462 system using the SPHERE instrument on the Very Large Telescope (VLT) in 2015 and 2016, we measure the pattern motion for its two prominent spiral arms in polarized light. On one hand, if both arms are comoving, they can be driven by a planet at $86_{-13}^{+18}$ au on a circular orbit, with gravitational instability motion ruled out. On the other hand, they can be driven by two planets at $120_{-30}^{+30}$ au and $49_{-5}^{+6}$ au, offering a tentative evidence (3.0$σ$) that the two spirals are moving independently. The independent arm motion is possibly supported by our analysis of a re-reduction of archival observations using the NICMOS instrument onboard the Hubble Space Telescope (HST) in 1998 and 2005, yet artifacts including shadows can manifest spurious arm motion in HST observations. We expect future re-observations to better constrain the motion mechanism for the SAO 206462 spiral arms.
