Image credits: ESA & Planck Collaboration

The diagram above illustrates the interaction of a non-spherical dust grain with both the magnetic field and the radiation field or gas flow. The grain-radiation or grain-gas flow interaction generates RAdiative Torques (RATs) or MEchanical Torques (METs), which together with magnetic fields drive several key physical processes, including suprathermal grain rotation, grain alignment with magnetic fields, and grain rotational disruption. These processes, in turn, play a fundamental role in shaping various astrophysical processes and phenomena. This project aims to further develop the RAT and MET paradigms and extend their application across the cosmic ecosystem.

Note: The acronym RAT was first introduced in 2007 by Thiem Hoang, in collaboration with Alex Lazarian, as a compact term for RAdiative Torque. While unintentional, the acronym also resonates with the symbolic attributes of the rat in Asian cultures—intelligence, adaptability, and especially a pioneering spirit— as the first sign in the zodiac. Please don't be confused with the RAT used in wireless communication for Radio Access Technology or in Aviation for Ram Air Turbine.

From Truong & Hoang (2025, ApJ)