Speaker: Dr. Le Ngoc Tram (MPIfR Bonn), Host: Dr. Thiem Hoang (KASI & UST, South Korea)

Abstract: Absorption polarization from interstellar dust was discovered in the 50s, and emission polarization was first reported in the 80s. Many more dust polarization observations with higher sensitivity and resolution have been deployed in the last decades. Theories have also been proposed and updated to understand observations comprehensively. The most popular theory is the Radiative Torque Alignment (RAT-A), which relies on the interaction between an incident anisotropic radiation field and an irregular-shaped dust grain. Recently, suprathermal dust rotation by radiative torques has been found to induce rotational fragmentation of the largest grains. This new non-thermal disruption is called Radiative Torque Disruption (RAT-D). The combination of the RAT-A theory and the RAT-D mechanism is known as the RAT paradigm. The vast majority of predictions made by the RAT paradigm have been tested from observations. In this talk, I review the fundamentals of the RAT paradigm and the application for single and multiple-wavelength observations, both from dust absorption and emission polarization.

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