The Appearance of Vortices in Protoplanetary Disks in Near-Infrared Scattered Light

Abstract

Azimuthally asymmetric structures have been discovered in millimeter continuum emission from many protoplanetary disks. One hypothesis is that they are vortices produced by the Rossby wave instability, for example at edges of planet-opened gaps or deadzones. Confirming the vortex nature of these structures will have profound implications to planet formation. One way to test the hypothesis is to compare the observed morphology of vortex candidates in near-infrared scattered light with theoretical expectations. To this end, we synthesize the appearance of vortices in H-band polarized light by combining hydrodynamic and radiative transfer simulations of the Rossby wave instability at a deadzone edge. In a disk at 140 pc, at the peak in its evolution a vortex at 65 au may appear as a radially narrow arc 50% - 70% brighter compared with an axisymmetric disk model. The contrast depends on the inclination of the disk and the position angle of the vortex only weakly. Such contrast levels are well detectable in imaging observations of bright disks using instruments such as VLT/SPHERE, Subaru/SCExAO, and Gemini/GPI. A vortex also casts a shadow in the outer disk, which may aid its identification. Finally, at modest to high inclinations (e.g., 60 degrees) a vortex may mimic a one-armed spiral. In the HD 34282 disk, such a one-armed spiral with a shadowed region on the outside has been found in scattered light. This feature roughly coincides with an azimuthal asymmetry in mm continuum emission, signifying the presence of a vortex.

10 pages, 7 figures, ApJ accepted

References in corpus (20)

• Gaps, Rings, and Non-Axisymmetric Structures in Protoplanetary Disks - From Simulations to ALMA Observations
• Asymmetric features in the protoplanetary disk MWC758
• One Solution to the Mass Budget Problem for Planet Formation: Optically Thick Disks with Dust Scattering
• Protoplanetary disk rings and gaps across ages and luminosities
• Direct detection of scattered light gaps in the transitional disk around HD 97048 with VLT/SPHERE
• The anomalously low (sub)millimeter spectral indices of some protoplanetary disks may be explained by dust self-scattering
• Dust Trapping by Vortices in Transitional Disks: Evidence for Non-ideal MHD Effects in Protoplanetary Disks
• On the Stability of Elliptical Vortices in Accretion Discs
• On the origin of horseshoes in transitional discs
• Vortices and spirals in the HD135344B transition disk
• The Sizes and Depletions of the Dust and Gas Cavities in the Transitional Disk J160421.7-213028
• Dust traps in the protoplanetary disc MWC 758: two vortices produced by two giant planets?
• Slowly-growing gap-opening planets trigger weaker vortices
• Scattered light mapping of protoplanetary disks
• Signatures of an eccentric disc cavity: Dust and gas in IRS 48
• A 80 au cavity in the disk around HD 34282
• Surface Geometry of Protoplanetary Disks Inferred From Near-Infrared Imaging Polarimetry
• A Layered Debris Disk around M Star TWA 7 in Scattered Light
• Dynamical signatures of Rossby vortices in cavity-hosting disks
• Constraining the masses of planets in protoplanetary discs from the presence or absence of vortices -- Comparison with ALMA observations

Cited by in corpus (3)

• Imaging the inner astronomical unit of Herbig Be star HD 190073
• Emergence of vortices at the edges of planet-driven gaps in protoplanetary discs
• Multiple Rings and Asymmetric Structures in the Disk of SR 21