Substructures induced by dust drag in protoplanetary disks

Dust substructures observed in protoplanetary disks are commonly attributed to embedded planets; however, intrinsic gas--dust interactions can also generate complex morphologies. We performed two-dimensional, axisymmetric simulations of gas and dust that include dust back-reaction and parameterized turbulence to investigate how the streaming instability (SI) and vertical shear instability (VSI) shape dust distributions. With moderate viscosity and sufficiently high metallicity, we identify a cha