GRAVITATIONAL ACCRETION OF PARTICLES ONTO MOONLETS EMBEDDED IN SATURN's RINGS

Yasui, Yuki; Ohtsuki, Keiji; Daisaka, Hiroshi

doi:10.1088/0004-637X/797/2/93

Title: GRAVITATIONAL ACCRETION OF PARTICLES ONTO MOONLETS EMBEDDED IN SATURN's RINGS

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Abstract

Using a local N-body simulation, we examine gravitational accretion of ring particles onto moonlet cores in Saturn's rings. We find that gravitational accretion of particles onto moonlet cores is unlikely to occur in the C ring and probably difficult in the inner B ring as well provided that the cores are rigid water ice. Dependence of particle accretion on ring thickness changes when the radial distance from the planet and/or the density of particles is varied: the former determines the size of the core's Hill radius relative to its physical size, while the latter changes the effect of self-gravity of accreted particles. We find that particle accretion onto high-latitude regions of the core surface can occur even if the rings' vertical thickness is much smaller than the core radius, although redistribution of particles onto the high-latitude regions would not be perfectly efficient in outer regions of the rings such as the outer A ring, where the size of the core's Hill sphere in the vertical direction is significantly larger than the core's physical radius. Our results suggest that large boulders recently inferred from observations of transparent holes in the C ring are not formed locally by gravitational accretion, while propellermore »« less

Authors:

Yasui, Yuki; Ohtsuki, Keiji ^[1]; Daisaka, Hiroshi ^[2]

Department of Earth and Planetary Sciences, Kobe University, Kobe 657-8501 (Japan)
Graduate School of Commerce and Management, Hitotsubashi University, Tokyo 186-8601 (Japan)

Publication Date:: Sat Dec 20 00:00:00 EST 2014

OSTI Identifier:: 22364854

Resource Type:: Journal Article

Journal Name:: Astrophysical Journal

Additional Journal Information:: Journal Volume: 797; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X

Country of Publication:: United States

Language:: English

Subject:: 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COMPUTERIZED SIMULATION; DENSITY; DISTANCE; GRAVITATION; ICE; PARTICLES; PLANET-SYSTEM ACCRETION; RINGS; SATELLITES; SATURN PLANET; SOLAR SYSTEM EVOLUTION; WATER

Citation Formats


                    Yasui, Yuki, Ohtsuki, Keiji, and Daisaka, Hiroshi. GRAVITATIONAL ACCRETION OF PARTICLES ONTO MOONLETS EMBEDDED IN SATURN's RINGS.  United States: N. p., 2014. 
        Web.  doi:10.1088/0004-637X/797/2/93.

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                    Yasui, Yuki, Ohtsuki, Keiji, & Daisaka, Hiroshi. GRAVITATIONAL ACCRETION OF PARTICLES ONTO MOONLETS EMBEDDED IN SATURN's RINGS.  United States.  https://doi.org/10.1088/0004-637X/797/2/93

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                    Yasui, Yuki, Ohtsuki, Keiji, and Daisaka, Hiroshi. 2014.  
        "GRAVITATIONAL ACCRETION OF PARTICLES ONTO MOONLETS EMBEDDED IN SATURN's RINGS".  United States.  https://doi.org/10.1088/0004-637X/797/2/93.

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@article{osti_22364854,

  title        = {GRAVITATIONAL ACCRETION OF PARTICLES ONTO MOONLETS EMBEDDED IN SATURN's RINGS},

  author       = {Yasui, Yuki and Ohtsuki, Keiji and Daisaka, Hiroshi},

  abstractNote = {Using a local N-body simulation, we examine gravitational accretion of ring particles onto moonlet cores in Saturn's rings. We find that gravitational accretion of particles onto moonlet cores is unlikely to occur in the C ring and probably difficult in the inner B ring as well provided that the cores are rigid water ice. Dependence of particle accretion on ring thickness changes when the radial distance from the planet and/or the density of particles is varied: the former determines the size of the core's Hill radius relative to its physical size, while the latter changes the effect of self-gravity of accreted particles. We find that particle accretion onto high-latitude regions of the core surface can occur even if the rings' vertical thickness is much smaller than the core radius, although redistribution of particles onto the high-latitude regions would not be perfectly efficient in outer regions of the rings such as the outer A ring, where the size of the core's Hill sphere in the vertical direction is significantly larger than the core's physical radius. Our results suggest that large boulders recently inferred from observations of transparent holes in the C ring are not formed locally by gravitational accretion, while propeller moonlets in the A ring would be gravitational aggregates formed by particle accretion onto dense cores. Our results also imply that the main bodies of small satellites near the outer edge of Saturn's rings may have been formed in rather thin rings.},

  doi          = {10.1088/0004-637X/797/2/93},

  url          = {https://www.osti.gov/biblio/22364854},
  journal      = {Astrophysical Journal},

  issn         = {0004-637X},

  number       = 2,

  volume       = 797,

  place        = {United States},

  year         = {Sat Dec 20 00:00:00 EST 2014},

  month        = {Sat Dec 20 00:00:00 EST 2014}

}

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