Abstract

Contributed Talk - Splinter DustEvol

Thursday, 12 September 2024, 15:20   (S12)

The dynamics and evolution of rotating dust grains

Stefan Reissl, Paul Meehan, Jonathan Jäger, Ralf Klessen
Institut für Theoretische Astrophysik

Dust is a ubiquitous component of the interstellar medium (ISM) and plays a crucial role in regulating astrophysical processes, including star formation, gas heating and cooling, planet formation, and surface chemistry. In this talk, I present my latest research on the microphysics and dynamical processes related to interstellar dust grains. The alignment of these grains with the magnetic field orientation is closely tied to rapid grain rotation. However, grain rotation is a critical process that is often overlooked in modeling the alignment, surface chemistry, and growth of interstellar dust. I present results from self-consistent N-body simulations of complex rotating dust aggregates. These simulation results offer an explanation for the observed flattened grain shapes in the ISM and the sudden disruption of larger grains. Additionally, I introduce a new model of the mechanical alignment of dust (MAD) through gas collisions, serving as a complementary spin-up mechanism to the canonical radiative torques. I demonstrate how the free parameters of the MAD model can be constrained using Monte Carlo simulations of gas-dust collisions. Finally, I discuss potential observational tests that can support the MAD model.