Modelling circumbinary protoplanetary disks. I. Fluid simulations of the Kepler16 and 34 systems
Abstract
Context. The Kepler mission's discovery of a number of circumbinary planets orbiting close (a_{p}< 1.1 au) to the stellar binary raises questions as to how these planets could have formed given the intense gravitational perturbations the dual stars impart on the disk. The gas component of circumbinary protoplanetary disks is perturbed in a similar manner to the solid, planetesimal dominated counterpart, although the mechanism by which disk eccentricity originates differs.
Aims: This is the first work of a series that aims to investigate the conditions for planet formation in circumbinary protoplanetary disks.
Methods: We present a number of hydrodynamical simulations that explore the response of gas disks around two observed binary systems: Kepler16 and Kepler34. We probe the importance of disk viscosity, aspectratio, inner boundary condition, initial surface density gradient, and selfgravity on the dynamical evolution of the disk, as well as its quasisteadystate profile.
Results: We find there is a strong influence of binary type on the mean disk eccentricity, e̅_{d}, leading to e̅_{d} = 0.02  0.08 for Kepler16 and e̅_{d} = 0.10  0.15 in Kepler34. The value of αviscosity has little influence on the disk, but we find a strong increase in mean disk eccentricity with increasing aspectratio due to wave propagation effects. The choice of inner boundary condition only has a small effect on the surface density and eccentricity of the disk. Our primary finding is that including disk selfgravity has little impact on the evolution or final state of the disk for disks with masses less than 12.5 times that of the minimummass solar nebula. This finding contrasts with the results of selfgravity relevance in circumprimary disks, where its inclusion is found to be an important factor in describing the disk evolution.
 Publication:

Astronomy and Astrophysics
 Pub Date:
 October 2015
 DOI:
 10.1051/00046361/201526295
 arXiv:
 arXiv:1507.06998
 Bibcode:
 2015A&A...582A...5L
 Keywords:

 hydrodynamics;
 methods: numerical;
 planets and satellites: formation;
 protoplanetary disks;
 binaries: close;
 Astrophysics  Earth and Planetary Astrophysics
 EPrint:
 Accepted to A&