FORMING the COLD CLASSICAL KUIPER BELT in A LIGHT DISK

Andrew Shannon, Yanqin Wu, Yoram Lithwick

Research output: Contribution to journalArticle

14 Scopus citations

Abstract

Large Kuiper Belt objects are conventionally thought to have formed out of a massive planetesimal belt that is a few thousand times its current mass. Such a picture, however, is incompatible with multiple lines of evidence. Here, we present a new model for the conglomeration of Cold Classical Kuiper Belt objects, out of a solid belt only a few times its current mass, or a few per cent of the solid density in a Minimum Mass Solar Nebula. This is made possible by depositing most of the primordial mass in grains of centimeter size or smaller. These grains collide frequently and maintain a dynamically cold belt out of which large bodies grow efficiently: an order-unity fraction of the solid mass can be converted into large bodies, in contrast to the ∼10-3 efficiency in conventional models. Such a light belt may represent the true outer edge of the solar system, and it may have effectively halted the outward migration of Neptune. In addition to the high efficiency, our model can also produce a mass spectrum that peaks at an intermediate size, similar to the observed Cold Classicals, if one includes the effect of cratering collisions. In particular, the observed power-law break observed at ∼30 km for Cold Classicals, one that has been interpreted as a result of collisional erosion, may be primordial in origin.

Original languageEnglish (US)
Article number175
JournalAstrophysical Journal
Volume818
Issue number2
DOIs
StatePublished - Feb 20 2016

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Keywords

  • Kuiper Belt: general
  • circumstellar matter
  • planetary systems
  • planets and satellites: formation

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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