Outward migration of a super-Earth in a disc with outward propagating density waves excited by a giant planet
Article first published online: 9 FEB 2012
© 2012 The Authors Monthly Notices of the Royal Astronomical Society © 2012 RAS
Monthly Notices of the Royal Astronomical Society
Volume 421, Issue 2, pages 1736–1756, April 2012
How to Cite
Podlewska-Gaca, E., Papaloizou, J. C. B. and Szuszkiewicz, E. (2012), Outward migration of a super-Earth in a disc with outward propagating density waves excited by a giant planet. Monthly Notices of the Royal Astronomical Society, 421: 1736–1756. doi: 10.1111/j.1365-2966.2012.20433.x
- Issue published online: 16 MAR 2012
- Article first published online: 9 FEB 2012
- Accepted 2011 December 21. Received 2011 December 20; in original form 2011 October 3
- methods: numerical;
- planets and satellites: formation;
- planet–disc interactions
In this paper, we consider a new mechanism for stopping the inward migration of a low-mass planet embedded in a gaseous protoplanetary disc. It operates when a low-mass planet (for example a super-Earth) encounters outgoing density waves excited by another source in the disc. This source could be a gas giant in an orbit interior to that of the low-mass planet. As the super-Earth passes through the wave field, angular momentum is transferred to the disc material and then communicated to the planet through co-orbital dynamics, with the consequence that its inward migration can be halted or even reversed.
We illustrate how the mechanism we consider works in a variety of different physical conditions employing global two-dimensional hydrodynamical calculations. We confirm our results by performing local shearing box simulations in which the super-Earth interacts with density waves excited by an independent harmonically varying potential. Finally, we discuss the constraints arising from the process considered here, on formation scenarios for systems containing a giant planet and lower mass planet in an outer orbit with a 2:1 commensurability such as GJ 876.