Secular Gravitational Instability of Drifting Dust in Protoplanetary Disks: Formation of Dusty Rings without Significant Gas Substructures
| Autor: | Ryosuke T. Tominaga, Shu-ichiro Inutsuka, Sanemichi Z. Takahashi |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Physics
Earth and Planetary Astrophysics (astro-ph.EP) Planetesimal Gravitational instability 010504 meteorology & atmospheric sciences Continuum (design consultancy) FOS: Physical sciences Astronomy and Astrophysics Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics 01 natural sciences Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science 0103 physical sciences Emissivity Likely outcome Substructure Astrophysics::Earth and Planetary Astrophysics Diffusion (business) 010303 astronomy & astrophysics Solar and Stellar Astrophysics (astro-ph.SR) Astrophysics::Galaxy Astrophysics 0105 earth and related environmental sciences Astrophysics - Earth and Planetary Astrophysics |
| Popis: | Secular gravitational instability (GI) is one of the promising mechanisms for creating annular substructures and planetesimals in protoplanetary disks. We perform numerical simulations of the secular GI in a radially extended disk with inward drifting dust grains. The results show that, even in the presence of the dust diffusion, the dust rings form via the secular GI while the dust grains are moving inward, and the dust surface density increases by a factor of ten. Once the secular GI develops into a nonlinear regime, the total mass of the resultant rings can be a significant fraction of the dust disk mass. In this way, a large amount of drifting dust grains can be collected in the dusty rings and stored for planetesimal formation. In contrast to the emergence of remarkable dust substructures, the secular GI does not create significant gas substructures. This result indicates that observations of a gas density profile near the disk midplane enable us to distinguish the mechanisms for creating the annular substructures in the observed disks. The resultant rings start decaying once they enter the inner region stable to the secular GI. Since the ring-gap contrast smoothly decreases, it seems possible that the rings are observed even in the stable region. We also discuss the likely outcome of the non-linear growth and indicate the possibility that a significantly developed region of the secular GI may appear as a gap-like substructure in dust continuum emission since dust growth into larger solid bodies and planetesimal formation reduce the total emissivity. 22 pages, 14 figures, accepted for publication in ApJ |
| Databáze: | OpenAIRE |
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