Dynamics of Porous Dust Aggregates and Gravitational Instability of Their Disk

Journal Article · Sat Jun 10 04:00:00 EDT 2017 · Astrophysical Journal

DOI:https://doi.org/10.3847/1538-4357/AA7388· OSTI ID:22872627

Michikoshi, Shugo ^[1]; Kokubo, Eiichiro ^[2]

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1. Center for Computational Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan)
2. Division of Theoretical Astronomy, National Astronomical Observatory of Japan, Osawa, Mitaka, Tokyo 181-8588 (Japan)

We consider the dynamics of porous icy dust aggregates in a turbulent gas disk and investigate the stability of the disk. We evaluate the random velocity of porous dust aggregates by considering their self-gravity, collisions, aerodynamic drag, turbulent stirring, and scattering due to gas. We extend our previous work by introducing the anisotropic velocity dispersion and the relaxation time of the random velocity. We find the minimum mass solar nebula model to be gravitationally unstable if the turbulent viscosity parameter α is less than about 4×10{sup −3}. The upper limit of α for the onset of gravitational instability is derived as a function of the disk parameters. We discuss the implications of the gravitational instability for planetesimal formation.

• OSTI ID: 22872627
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 842; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ANISOTROPY
COLLISIONS
COSMIC DUST
DISPERSIONS
GRAVITATION
GRAVITATIONAL INSTABILITY
MASS
PLANETS
PROTOPLANETS
RANDOMNESS
RELAXATION TIME
SATELLITES
SCATTERING
SOLAR NEBULA
VELOCITY