  We carry out three-dimensional SPH simulations to study whether planets can
survive in self-gravitating protoplanetary discs. The discs modelled here use a
cooling prescription that mimics a real disc which is only gravitationally
unstable in the outer regions. We do this by modelling the cooling using a
simplified method such that the cooling time in the outer parts of the disc is
shorter than in the inner regions, as expected in real discs. We find that both
giant (> M_Sat) and low mass (< M_Nep) planets initially migrate inwards very
rapidly, but are able to slow down in the inner gravitationally stable regions
of the disc without needing to open up a gap. This is in contrast to previous
studies where the cooling was modelled in a more simplified manner where
regardless of mass, the planets were unable to slow down their inward
migration. This shows the important effect the thermodynamics has on planet
migration. In a broader context, these results show that planets that form in
the early stages of the discs' evolution, when they are still quite massive and
self-gravitating, can survive.
