Embryos grown in the dead zone: Assembling the first protoplanetary cores in low mass self-gravitating circumstellar disks of gas and solids
2008 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 491, no 3, L41-L44 p.Article in journal (Refereed) Published
Context: In the borders of the dead zones of protoplanetary disks, the inflow of gas produces a local density maximum that triggers the Rossby wave instability. The vortices that form are efficient in trapping solids. Aims: We aim to assess the possibility of gravitational collapse of the solids within the Rossby vortices. Methods: We perform global simulations of the dynamics of gas and solids in a low mass non-magnetized self-gravitating thin protoplanetary disk with the Pencil Code. We use multiple particle species of radius 1, 10, 30, and 100 cm. The dead zone is modelled as a region of low viscosity. Results: The Rossby vortices excited in the edges of the dead zone are efficient particle traps. Within 5 orbits after their appearance, the solids achieve critical density and undergo gravitational collapse into Mars sized objects. The velocity dispersions are of the order of 10 m s-1 for newly formed embryos, later lowering to less than 1 m s-1 by drag force cooling. After 200 orbits, over 300 gravitationally bound embryos were formed, 20 of them being more massive than Mars. Their mass spectrum follows a power law of index -2.3 ± 0.2.
Place, publisher, year, edition, pages
2008. Vol. 491, no 3, L41-L44 p.
Accretion, accretion disks; Instabilites; Stars: planetary systems: formation
IdentifiersURN: urn:nbn:se:uu:diva-98000DOI: 10.1051/0004-6361:200810626ISI: 000261152900001OAI: oai:DiVA.org:uu-98000DiVA: diva2:173151