Streaming instability of the dust layer in a protoplanetary disk

Abstract

In the dust layer of a protoplanetary disk, a dust aggregate move toward a central star due to the gas friction. On the other hand, the gas moves outward by gaining the angular momentum. Thus, dust and gas move in the different directions, respectively. In this case, it is known that the streaming instability occurs. We performed numerical simulations of shear and streaming instabilities in the dust layer. Our simulations show that stronger instability occurs if the gradient of the dust profile exists.