Data di Pubblicazione:
2006
Citazione:
Planetesimal formation via fragmentation in self-gravitating protoplanetary discs / W.K.M. Rice, G. Lodato, J.E. Pringle, P.J. Armitage, I. Bonnell. - In: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY. - ISSN 0035-8711. - 372:1(2006 Oct), pp. L9-L13. [10.1111/j.1745-3933.2006.00215.x]
Abstract:
An unsolved issue in the standard core accretion model for gaseous planet formation is how
kilometre-sized planetesimals form from, initially, micron-sized dust grains. Solid growth
beyond metre sizes can be difficult both because the sticking efficiency becomes very small,
and because these particles should rapidly migrate into the central star. We consider here how
metre-sized particles evolve in self-gravitating accretion discs using simulations in which the
gravitational influence of the solid particles is also included. Metre-sized particles become
strongly concentrated in the spiral structures present in the disc and, if the solid to gas density
ratio is sufficiently high, can fragment because of their own self-gravity to form planetesimals
directly. This result suggests that planetesimal formation may occur very early in the star
formation process while discs are still massive enough to be self-gravitating. The dependence
of this process on the surface density of the solids is also consistent with the observation that
extrasolar planets are preferentially found around high-metallicity stars.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
Accretion, accretion discs; Gravitation; Instabilities; Planetary systems: formation; Planetary systems: protoplanetary discs; Stars: formation
Elenco autori:
W.K.M. Rice, G. Lodato, J.E. Pringle, P.J. Armitage, I. Bonnell
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