Planetary Signatures in the SAO 206462 (HD 135344B) Disk: A Spiral Arm Passing through Vortex?

摘要: The disk surrounding SAO 206462, an 8 Myr old Herbig Ae star, has recently been reported to exhibit spiral arms, asymmetric dust continuum, and a dust-depleted inner cavity. By carrying out two-dimensional, two-fluid hydrodynamic calculations, we find that planetary-mass companion located at the outer could be responsible for these observed structures. In this model, planet excites primary secondary arms interior its orbit. It also carves gap generates local pressure bump edge where vortex forms through Rossby wave instability. traps radially drifting particles, forming cavity in disk. We propose is brightest southwestern peak seen infrared scattered light sub-millimeter continuum emission. particular, it possible boosted as one of passes high density region, although alone may able explain peak. suggest planetary with mass 10–15 orbiting 206462 100–120 au. Monitoring over next few years will help reveal origin because show distinguishable displacement.