Disc and Planet Evolution in Circumbinary Systems
Abstract
The inner regions of discs around close binary systems are dominated by tidally truncated
eccentric cavities. These are believed to play a key role in dictating
where planets formed in these circumbinary discs halt their disc-driven migration.
In this thesis we present work examining processes which could impact the
evolution and structure of this region, and the planets which interact with it.
First, we investigate the role of self-gravity and disc-mass on circumbinary discs
and planets. The greatest impact of self-gravity was found in discs around highly
eccentric binaries, and in discs with high masses. In these cases, self-gravity
acts to compact the scale of the inner cavity region. For the highest disc masses,
additional eccentric features arise in the outer disc. A range of scenarios examining
planetary migration, accretion and disc dissipation find that if planets form and
evolve in a high-mass environment, the disc structures formed by self-gravity can
leave a fingerprint on the planetary architecture once the disc has dissipated.
We also significantly modify the publicly available fargo-adsg hydrodynamical
code, to include radiative effects such as disc irradiation by the binary stars,
radiative transport and disc surface cooling. We present preliminary results of
simulations of adiabatic circumbinary discs with these effects included, and consider
also the migration of protoplanets within them. Fully radiative discs produce
a smaller inner cavity than obtained in previous isothermal models – a promising
result for the end point of planet migration in these discs.
Whilst we have found significant alteration of the circumbinary enviroment by
self-gravity and radiative effects, future simulations that capture the 3-D nature
of these discs will be required to fully describe the observed architecture of the
circumbinary systems.
Authors
Mutter, Matthew MCollections
- Theses [4222]