Protostars and Planets VI, Heidelberg, July 15-20, 2013

Poster 2H040

On the Corotation Torque of Embedded Low-mass Eccentric Protoplanets

Fendyke, Stephen M. (Queen Mary, University of London)
Nelson, Richard P. (Queen Mary, University of London)

Abstract:
Embedded protoplanets in inviscid, isothermal protoplanetary discs rapidly migrate inward under the action of Lindblad torques (Type I migration). This behaviour can be slowed or even reversed by corotation torques, fuelled by sustained vortensity and entropy gradients across the corotation region. Previous work has suggested that this corotation torque attenuates for eccentric planets. We present results from a series of high-resolution 2D hydrodynamic simulations of low-mass eccentric protoplanets, from which we obtain the corotation torque as a function of eccentricity for disc aspect ratios between H/r=0.03 and H/r=0.10. We find an attenuation of corotation torque with increasing eccentricity for all disc aspect ratios, with a significant decrease for even modest eccentricities of the kind expected to be excited by planetplanet interaction. This attenuation is closely connected with the narrowing of the corotation region where material librates on horseshoe orbits under the influence of the planetís gravitational potential.

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