The Observer’s Guide to the Gamma-Ray Burst Supernova Connection

Figure 12

Schematic illustration of polarization in the SN ejecta. (a) When the photosphere is spherical, polarization is canceled out, and no polarization is expected. At the wavelength of a line, polarization produced by the electron scattering is depolarized by the line transition. (b) When the ion distribution is spherical, the remaining polarization is canceled, and no polarization is expected. (c) When the ion distribution is not spherical, the cancelation becomes incomplete, and line polarization could be detected (figure and caption taken from [241]).