Roman Virtual Lecture

Apr. 15, 2021

Speaker (Affiliation):
Russell Ryan (STScI)

Galactic Archaeology with Brown Dwarfs with the Nancy Grace Roman Space Telescope


I will discuss the large-scale distribution and properties of brown dwarfs in the Milky Way. I will present semi-analytic modeling of the Galaxy to predict the observed distribution functions (ie. luminosity, effective temperature) and kinematics. This model shows that since brown dwarfs are cooling throughout their lifetimes, they should have a lower vertical velocity dispersion and populate a thinner Galactic disk than late-type main-sequence stars. I will discuss the limitations of current space- and ground-based surveys to constrain the evolutionary properties of brown dwarfs and their application to Galactic archaeology. With its very wide-field, medium-deep infrared imaging and spectroscopy, and high angular resolution, the Nancy Grace Roman Space Telescope is expected to find >10^4 brown dwarfs at <10 kpc, which makes it the ideal laboratory to examine the evolution of brown dwarfs by their Galactic-scale distribution and properties.