No Sub-Saturn Mass Planet Desert in the CORALIE/HARPS Radial Velocity Sample

TL;DR

This study analyzes the CORALIE/HARPS exoplanet data to test the predicted planet mass desert caused by runaway gas accretion, finding no evidence for such a desert and challenging core accretion theory predictions.

Contribution

It provides the first observational test of the predicted planet mass desert at 10-100 M_ ext{Jup} using radial velocity data, showing no such desert exists.

Findings

No evidence of the predicted planet mass desert.

Results align with microlensing surveys showing no desert.

Implications for planet formation theories.

Abstract

We analyze the CORALIE/HARPS sample of exoplanets (Mayor et al. 2011) found by the Doppler radial velocity method for signs of the predicted "desert" at 10-$100 M_\odot$ caused by runaway gas accretion at semimajor axes of $< 3\,$AU. We find that these data are not consistent with this prediction. This result is similar to the finding by the MOA gravitational microlensing survey that found no desert in the exoplanet distribution for exoplanets in slightly longer period orbits and somewhat lower host masses (Suzuki et al. 2018). Together, these results imply that the runaway accretion scenario of the core accretion theory does not have a large influence on the final mass and semimajor axis distribution of exoplanets.