Predictions of the Nancy Grace Roman Space Telescope Galactic Exoplanet Survey II: Free-Floating Planet Detection Rates

Understand

The Nancy Grace Roman Space Telescope (Roman) will perform a Galactic Exoplanet Survey (RGES) to discover bound exoplanets with semi-major axes greater than 1 au using gravitational microlensing.

• Roman will even be sensitive to planetary mass objects that are not gravitationally bound to any host star.
• Such free-floating planetary mass objects (FFPs) will be detected as isolated microlensing events with timescales shorter than a few days.
• A measurement of the abundance and mass function of FFPs is a powerful diagnostic of the formation and evolution of planetary systems, as well as the physics of the formation of isolated objects via direct collapse.