Stoyanovskaya O.P.   Снытников В.Н.   Снытников Н.В.   Воробьев Э.И.   Жилкин А.Г.  

The burst mode of accretion in massive circumstellar discs: simulations with Smoothed Particle Hydrodynamics and grid-based gravitational solver

Reporter: Stoyanovskaya O.P.

THE BURST MODE OF ACCRETION IN MASSIVE CIRCUMSTELLAR DISCS: SIMULATIONS WITH SMOOTHED PARTICLE HYDRODYNAMICS AND GRID-BASED GRAVITATIONAL SOLVER

O. P. Stoyanovskaya 1,2, N. V. Snytnikov 3, E. I. Vorobyov5,6, A. G. Zhilkin4, V. N. Snytnikov 1,2
1IC SB RAS, Novosibirsk2;  Novosibirsk state university, Novosibirsk;
3ICMMG SB RAS, Novosibirsk;   4INASAN, Moscow;
5Sourthen federal university, Rostov-on-Don
6Department of Astrophysics, University of Vienna, Vienna, Austria
stop@catalysis.ru, nik@ssd.sscc.ru, eduard.vorobiev@univie.ac.at, zhilkin@inasan.ru, snyt@catalysis.ru

We present a numerical algorithm for modeling transient phenomena of gravitational gas dynamics applied to simulations of protostellar accretion in gravitationally unstable disks. The algorithm is based on the Smoothed particle hydrodynamics (SPH) combined with a grid-based solver for the Poisson equation. This combination of methods allows treating the formation and long-term migration of high-density clumps in massive gaseous discs with acceptable time-stepping and without introduction of inhomogeneities in the SPH (such as the sink particle technique developed to treat the global disc dynamics when local gravitational collapse take place in the medium [1]). Practically important features of coupling the SPH with the grid-based solver and numerical issues with a large number of SPH neighbors are discussed in the paper.  We found that the accretion rate of gas on the central body for self-regulated and fragmenting discs obtained by our numerical algorithm is in good agreement with results of other numerical simulations of protostellar accretion.  The existence of the burst mode of accretion first studied with the grid-based code by Vorobyov and Basu 2005 [2] was confirmed using the SPH simulations.
The project has been partially supported by Ministry of Science and Education of Russian Federation, grants RFBR 14–01–31516, 14–01–31088, 15-32-51204, 14-02-00719.

REFERENCES
1. Bate M.R., Bonnell I.A., Price N.M. Modeling accretion in protobinary systems // MNRAS. 1995. V. 277. P. 362-376.

2. Vorobyov E.I., Basu S. The origin of episodic accretion bursts in the early stages of star formation // The Astrophysical Journal. 2005. V. 633. L137-L140.


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