As the only large spiral galaxy in which we can study a significant fraction of the individual stars, the Milky Way offers astronomers a unique laboratory to study the processes that shape galaxies. As much of our fundamental understanding of astrophysics is anchored in the Milky Way, study of our Galaxy is critical to broad areas of astrophysics, including extragalactic astronomy. Ongoing surveys are transforming our understanding of the Milky Way by precisely determining distances, kinematics and elemental abundances of hundreds of millions of stars. My research program focuses on applying new computational methods to this unprecedented volume of high-quality Milky Way (MW) data. I focus on two areas of MW astrophysics: determining the gravitational potential using stellar kinematics, thus uncovering the distribution of dark matter on sub-galactic scales and putting constraints on the cold dark matter paradigm in this regime; and determining the distribution, properties and evolution of interstellar dust, which plays a key role in the chemistry of the interstellar medium (ISM) and affects myriad astronomical observations. Using 130 million low-resolution Gaia stellar spectra, my research group has developed the first 3D map of variations in the dust extinction curve, shedding light on the properties of dust throughout the Galaxy. My group has also pioneered a method for determining the gravitational potential from stellar kinematics, using computational tools borrowed from machine learning, which we are now applying to Gaia data. Together with advances in computational methods, large new datasets, such as Gaia Data Release 4, CSST, SPHEREx and Roman will transform our knowledge of the structure and dynamics of the Milky Way forward in the coming decade.
BIO
Dr. Gregory Green studies the structure and dynamics of the Milky Way, with a particular focus on both the three-dimensional distribution of interstellar dust, and on kinematic modeling to uncover the gravitational potential - and thus the distribution of dark matter in our Galaxy. He was awarded a Sofja Kovalevskaja Prize by the Alexander von Humboldt Foundation in 2020 to found and lead his current research group at the Max Planck Institute for Astronomy in Heidelberg, Germany. Dr. Green previously worked with Prof. Risa Wechsler as a Porat Postdoctoral Fellow at the Kavli Institute for Particle Astrophysics and Cosmology at Stanford University. He obtained his Ph.D. from Harvard University in 2016 under the supervision of Prof. Douglas Finkbeiner, creating the first large-scale three-dimensional map of dust in the Milky Way. As an undergraduate, he studied physics, history and German at the University of Michigan, where he worked with Prof. August Evrard on cosmology. Outside of astronomy, Dr. Green takes a keen interest in languages, having studied German, French and Mandarin Chinese, and in hiking in the Alps.
