Optical starlight polarization surveys

Image credit: Fosalba et al (2002)

Optical and near-infrared observations of linear polarization of stars have been used for decades to study magnetic fields and dust properties in clouds and filaments. Now, we are applying this technique also to characterize the global magnetic field in the Milky Way, probing the diffuse (though dusty) gas.

This project uses two exciting optical (V-band) surveys of stellar polarization, led by prof. Antonio Mario Magalhães (at IAP, São Paulo). These are:

• the SOUTH POL survey, an all-southern-sky survey which will be executed in the coming years at the Laborató Nacional de Astrofísica in Brazil.
• the Interstellar Polarization Survey (IPS). This is a pilot survey for SOUTH POL, of carefully selected fields of view in and around the Galactic plane. In this project, we have focused on the fields directed at "the general ISM", and developed methods to derive Galactic magnetic field information from these data.