Institute for Advanced Study Astrophysics Seminar
Searching for “Lonely” Dark Objects with Microlensing
Galactic microlensing is the only known method to discover dark objects ranging from isolated stellar-mass black holes (BHs) down to Earth-mass free-floating planets (FFPs). The recent success of interferometric resolution of microlensed images with VLTI opens up a new venue for discovering isolated stellar remnants. I discuss how the VLTI-GRAVITY(+) instrument can significantly advance such discoveries, potentially leading to measuring the mass function of isolated stellar-mass BHs. Ground-based surveys have found more than a dozen ultra-short microlensing events, with the intriguing implication that FFPs are a few times more common than planets bound to stars. I will discuss the prospect of future space-based microlensing surveys to discover and characterize a large sample of low-mass FFPs.