Multiple scattering polarization – Application of Chandrasekhar’s formalisms to the atmosphere of brown dwarfs and extrasolar planets

摘要

Chandrasekhar’s formalisms for the transfer of polarized radiation are used to explain the observed dust scattering polarization of brown dwarfs in the optical band. Model polarization profiles for hot and young directly imaged extrasolar planets are presented with specific prediction of the degree of polarization in the infrared. The model invokes Chandrasekhar’s formalism for the rotation-induced oblateness of the objects that gives rise to the necessary asymmetry for yielding net non-zero disk integrated linear polarization. The observed optical polarization constrains the surface gravity and could be a tool to estimate the mass of extrasolar planets.