The origin of the occurrence rate profile of gas giants inside 100 d

The origin of the occurrence rate profile of gas giants inside 100 d

We investigate the origin of the period distribution of giant planets. We fit the bias-corrected distribution of gas-giant planets inside 300 d found by Santerne et al. using a planet formation model based on pebble accretion. We investigate two possible initial conditions: a linear distribution of planetary seeds, and seeds injected exclusively on the water and CO icelines. Our simulations exclude the linear initial distribution of seeds with a high degree of confidence. Our bimodal model based on snowlines gives a more reasonable fit to the data, with the discrepancies reducing significantly if we assume the water snowline to be a factor of 3-10 less efficient at producing planets. This model moreover performs better on both the warm/hot Jupiters ratio and a Gaussian mixture model as comparison criteria. Our results hint that the gas-giant exoplanets population inside 300 d is more compatible with planets forming preferentially at special locations.

This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2017 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.