Icy pebbles surviving the meter-size barrier in the ice dominant region of protoplanetary disks

Pebble growth through collisions between like-sized dust and ice grains is one of the first steps in planet formation. However, this growth comes to a complete stop once these grains reach millimeter- to meter-sizes depending on where they are in their protoplanetary disk. Collisions at these sizes lead to fragmentation rather than growth and the pebbles rapidly inspiral towards their host-star before they are able to grow. This is known as the meter-size barrier of planet formation. Previous studies of grain evolution make many simplifying assumptions about the grain dynamics and compositions resulting in an incomplete understanding of whether all grains undergo collisional fragmentation. We create an analytic model considering all the relevant drag forces, material compositions, protoplanetary disk properties, and icelines in order to test grain stability and motion across an extremely broad parameter space. We find that for certain grain compositions in the outer disk, namely H₂O, CO₂, and CO ice, fragmentation may not be a dominating factor and can potentially allow particles to grow to large sizes where the growth barriers are no longer relevant.