Evolution of the Solar Nebula. VII. Formation and Survival of Protoplanets Formed by Disk Instability

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

64

Instabilities, Stars: Planetary Systems, Solar System: Formation

Scientific paper

A major concern for the disk instability mechanism for giant planet formation is survival of the self-gravitating clumps that form in a marginally gravitationally unstable disk. Previous grid-based calculations have found that these clumps may only survive for an orbital period or two, an outcome that has been attributed to insufficient spatial resolution of the clumps. Here we use the highest spatial resolution grid-based models to date (effectively over 8×106 grid points, with a locally refined radial grid and 1024 azimuthal grid points) to demonstrate that clump formation and survival are enhanced as the numerical resolution is increased, even with a full treatment of disk thermodynamics and radiative transfer. The overall disk evolution appears to be converging toward a solution with robust spiral arms and self-gravitating protoplanets. The survival of these protoplanets is then further explored by introducing ``virtual protoplanets,'' point masses representing massive protoplanets that accrete gas from the disk and interact with the disk as they orbit around the protostar. While growing cores and protoplanets formed by core accretion are thought to be subject to significant orbital migration, the virtual protoplanet models show that protoplanets formed by disk instability are likely to avoid rapid inward orbital migration, at least initially, because the self-gravitating disk gas flows inward, past the protoplanets, while the protoplanets orbit relatively undisturbed. Subsequent orbital migration in this case may depend primarily on the outer disk lifetime and hence on the star-forming environment, i.e., whether it is Taurus-like with relatively long-lived outer disks or Orion-like with relatively short-lived outer disks. The latter environment should lead to minimal inward orbital migration, as appears to be the case for our solar system, while the former may lead to sufficient inward migration to produce the observed short-period gas giant planets.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Evolution of the Solar Nebula. VII. Formation and Survival of Protoplanets Formed by Disk Instability does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Evolution of the Solar Nebula. VII. Formation and Survival of Protoplanets Formed by Disk Instability, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Evolution of the Solar Nebula. VII. Formation and Survival of Protoplanets Formed by Disk Instability will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1346924

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.