DIX Planetary Science Seminar

The snowline in protoplanetary disks is often invoked as a location for rapid dust accumulation and ensuing planetesimal formation. While dust is recognized as the primary source of disk opacity, the question of how its accumulation drives snowline evolution remains largely unaddressed. Here, we simulate the disk temperature response to evolving radial distributions of rocky and icy dust, as well as water vapor. Across typical ranges of disk parameters, the snowline naturally evolves into an extended region few AU wide, held at its defined temperature, within thousands of years. This region, termed the ``snowband," facilitates rapid planetesimal formation and pebble accretion owing to the enhanced ``stickiness" and size of near-sublimation pebbles. We incorporate the snowband into a revised model for the origin of non-carbonaceous (NC) and carbonaceous (CC) Solar System planetesimals, showing that it accommodates the diverse oxidation states of NC bodies, and the segregation of NC and CC materials via an early formed Jupiter. Applying the snowband framework to extrasolar systems, we show that it naturally explains the correlation between stellar metallicity and giant planet occurrence. In particular, giant planets form more readily around high-metallicity stars as greater dust abundance translates to wider snowbands wherein pebble accretion is favored.