Star formation in the Galactic Centre and across cosmic time
Observations of star forming regions in the solar neighbourhood provide the empirical foundation for our current understanding of star and planet formation. In this paradigm, gas is converted into stellar systems in an environmentally independent process which can be described by “universal” dense-gas-star-formation relations. The resulting stellar systems form in isolation, and there is minimal dynamical evolution of planetary architectures after they have finished forming and left their natal environment.
I will share recent results using the Galactic Centre as a laboratory to test this paradigm in conditions which are more cosmologically representative of the environment in which most stars in the Universe formed. We find that “universal” dense-gas-star-formation relations fail to describe the conversion of gas into stars — star formation is inhibited in collapsing gas clouds until they reach densities orders of magnitude higher than predicted critical densities. When star formation eventually begins, the proto-stellar densities are so high that stellar feedback is expected to destroy proto-planetary disks on ~Myr timescales — the epoch over which planets assemble the bulk of their mass. Finally, we find evidence that the extreme orbits of `Hot Jupiter’ exoplanets originate from environmental perturbations rather than internal migration or planet-planet scattering.
These results point to a paradigm in which environment is a key factor determining the outcome of the star and planet formation process, and the evolution of the planetary system architectures, over cosmic time. I will end by discussing the potential implications of these results in the context of the question that motivated this research, ‘Where do we expect to find life elsewhere in the Universe?’