The Migrating Embryo Model for Planet Formation

Author(s)

Shantanu Basu, E. Vorobyov

Abstract

A new view of disk evolution and planet formation is emerging from

self-consistent numerical simulation modeling of the formation of

circumstellar disks from the direct collapse of prestellar cloud cores.

A defining result is that the early evolution of a disk is crucially

affected by the continuing mass loading from the core envelope, with

recurrent phases of gravitational instability occurring in the disk.

Nonlinear spiral arms formed during these episodes fragment to form

gaseous clumps. These clumps generally migrate inward due to

gravitational torques arising from their interaction with a trailing

spiral arm. Occasionally, a clump can open up a gap in the disk and

settle into a stable orbit, revealing a direct pathway to the formation

of companion stars, brown dwarfs, or giant planets. At other times, when

multiple clumps are present, a low mass clump may even be ejected from

the system, providing a pathway to the formation of free-floating brown

dwarfs and giant planets in addition to low mass stars. Finally, the

inward migration of gaseous clumps may provide the proper conditions for

the transport of high-temperature processed solids from the outer disk

to the inner disk, and even possibly accelerate the formation of

terrestrial planets in the inner disk. All of these features arising

from clump formation and migration can be tied together conceptually in

a migrating embryo model that can complement the well-known core

accretion model for planet formation.

Organisation(s)

Department of Astrophysics

External organisation(s)

Case Western Reserve University

Publication date

01-2014

Peer reviewed

Yes

Austrian Fields of Science 2012

103004 Astrophysics

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