3-D SPH simulations of the FUOR flares in the clumpy accretion model

TL;DR

This study uses 3D hydrodynamic SPH simulations to explore how gas clump infall onto protoplanetary disks can trigger FUOR-like accretion bursts and create inclined inner disks, offering an alternative to planetary influence explanations.

Contribution

The paper demonstrates through simulations that clump infall can cause FUOR outbursts and produce inclined inner disks, providing a new perspective on disk inclination phenomena.

Findings

Clump infall causes FUOR-like accretion bursts.

Infall leads to formation of inclined gas rings and tilted disks.

Inner disk inclination decreases over time, reaching a few degrees after 100 revolutions.

Abstract

One of the early hypotheses about the origin of FUOR outbursts explains them by the fall of gas clumps from the remnants of protostellar clouds onto protoplanetary disks surrounding young stars (Hartmann and Kenyon 1985). To calculate the consequences of such an event we make 3D hydrodynamic simulations by SPH method. It is shown that the fall of the clump on the disk in the vicinity of the star actually causes a burst of the star's accretion activity, resembling in its characteristics the flares of known FUORs. In the region of incidence, an inhomogeneous gas ring is formed, which is inclined relative to the outer disk. During several revolutions around the star, this ring combines with the inner disk and forms a tilted disk. In the process of evolution, the inner disk expands, and its inclination relative to the outer disk decreases. After 100 revolutions, the angle of inclination is a few degrees. This result is of interest in connection with the discovery in recent years of protoplanetary disks, the inner region of which is inclined relative to the outer one. Such structures are usually associated with the existence in the vicinity of a star of a massive body (planet or brown dwarf), whose orbit is inclined relative to the plane of the disk. The results of our modeling indicate the possibility of an alternative explanation for this phenomenon.