Growing and moving low-mass planets in non-isothermal disks

Aims. We study the interaction of a low-mass planet with a protoplanetary disk with a realistic treatment of the energy balance by doing radiation-hydrodynamical simulations. We look at accretion and migration rates and compare them to isothermal studies. Methods. We used a three-dimensional version of the hydrodynamical method RODEO, together with radiative transport in the fluxlimited diffusion approach. Results. The accretion rate, as well as the torque on the planet, depen d critically on the ability of the disk to cool efficiently. Fo r densities appropriate to 5 AU in the solar nebula, the accret ion rate drops by more than an order of magnitude compared to isothermal models, while at the same time the torque on the planet is positive, indicating outward migration. It is necessary to lower the density by a factor of 2 to recover inward migration and more than 2 orders of magnitude to recover the usual Type I migration. The torque appears to be proportional to the radial entropy gradient in the unpe rturbed disk. These findings are critical for the survival of protoplanets, and they should ultimately find their way into population syn thesis models.