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Title: N-BODY SIMULATION OF PLANETESIMAL FORMATION THROUGH GRAVITATIONAL INSTABILITY AND COAGULATION. II. ACCRETION MODEL

Abstract

The gravitational instability of a dust layer is one of the scenarios for planetesimal formation. If the density of a dust layer becomes sufficiently high as a result of the sedimentation of dust grains toward the midplane of a protoplanetary disk, the layer becomes gravitationally unstable and spontaneously fragments into planetesimals. Using a shearing box method, we performed local N-body simulations of gravitational instability of a dust layer and subsequent coagulation without gas and investigated the basic formation process of planetesimals. In this paper, we adopted the accretion model as a collision model. A gravitationally bound pair of particles is replaced by a single particle with the total mass of the pair. This accretion model enables us to perform long-term and large-scale calculations. We confirmed that the formation process of planetesimals is the same as that in the previous paper with the rubble pile models. The formation process is divided into three stages: the formation of nonaxisymmetric structures; the creation of planetesimal seeds; and their collisional growth. We investigated the dependence of the planetesimal mass on the simulation domain size. We found that the mean mass of planetesimals formed in simulations is proportional to L {sup 3/2} {sub y}, wheremore » L{sub y} is the size of the computational domain in the direction of rotation. However, the mean mass of planetesimals is independent of L{sub x} , where L{sub x} is the size of the computational domain in the radial direction if L{sub x} is sufficiently large. We presented the estimation formula of the planetesimal mass taking into account the simulation domain size.« less

Authors:
;  [1];  [2]
  1. Center for Computational Astrophysics, National Astronomical Observatory of Japan, Osawa, Mitaka, Tokyo 181-8588 (Japan)
  2. Department of Physics, Kyoto University, Kyoto 606-8502 (Japan)
Publication Date:
OSTI Identifier:
21371902
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 703; Journal Issue: 2; Other Information: DOI: 10.1088/0004-637X/703/2/1363; Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COLLISIONS; DUSTS; GRAVITATION; GRAVITATIONAL INSTABILITY; MASS; PLANETS; PROTOPLANETS; ROTATION; SATELLITES; SIMULATION; INSTABILITY; MOTION; PLASMA INSTABILITY

Citation Formats

Michikoshi, Shugo, Kokubo, Eiichiro, and Inutsuka, Shu-ichiro. N-BODY SIMULATION OF PLANETESIMAL FORMATION THROUGH GRAVITATIONAL INSTABILITY AND COAGULATION. II. ACCRETION MODEL. United States: N. p., 2009. Web. doi:10.1088/0004-637X/703/2/1363.
Michikoshi, Shugo, Kokubo, Eiichiro, & Inutsuka, Shu-ichiro. N-BODY SIMULATION OF PLANETESIMAL FORMATION THROUGH GRAVITATIONAL INSTABILITY AND COAGULATION. II. ACCRETION MODEL. United States. https://doi.org/10.1088/0004-637X/703/2/1363
Michikoshi, Shugo, Kokubo, Eiichiro, and Inutsuka, Shu-ichiro. 2009. "N-BODY SIMULATION OF PLANETESIMAL FORMATION THROUGH GRAVITATIONAL INSTABILITY AND COAGULATION. II. ACCRETION MODEL". United States. https://doi.org/10.1088/0004-637X/703/2/1363.
@article{osti_21371902,
title = {N-BODY SIMULATION OF PLANETESIMAL FORMATION THROUGH GRAVITATIONAL INSTABILITY AND COAGULATION. II. ACCRETION MODEL},
author = {Michikoshi, Shugo and Kokubo, Eiichiro and Inutsuka, Shu-ichiro},
abstractNote = {The gravitational instability of a dust layer is one of the scenarios for planetesimal formation. If the density of a dust layer becomes sufficiently high as a result of the sedimentation of dust grains toward the midplane of a protoplanetary disk, the layer becomes gravitationally unstable and spontaneously fragments into planetesimals. Using a shearing box method, we performed local N-body simulations of gravitational instability of a dust layer and subsequent coagulation without gas and investigated the basic formation process of planetesimals. In this paper, we adopted the accretion model as a collision model. A gravitationally bound pair of particles is replaced by a single particle with the total mass of the pair. This accretion model enables us to perform long-term and large-scale calculations. We confirmed that the formation process of planetesimals is the same as that in the previous paper with the rubble pile models. The formation process is divided into three stages: the formation of nonaxisymmetric structures; the creation of planetesimal seeds; and their collisional growth. We investigated the dependence of the planetesimal mass on the simulation domain size. We found that the mean mass of planetesimals formed in simulations is proportional to L {sup 3/2} {sub y}, where L{sub y} is the size of the computational domain in the direction of rotation. However, the mean mass of planetesimals is independent of L{sub x} , where L{sub x} is the size of the computational domain in the radial direction if L{sub x} is sufficiently large. We presented the estimation formula of the planetesimal mass taking into account the simulation domain size.},
doi = {10.1088/0004-637X/703/2/1363},
url = {https://www.osti.gov/biblio/21371902}, journal = {Astrophysical Journal},
issn = {0004-637X},
number = 2,
volume = 703,
place = {United States},
year = {Thu Oct 01 00:00:00 EDT 2009},
month = {Thu Oct 01 00:00:00 EDT 2009}
}