Constraining the emission geometry and mass of the white Dwarf Pulsar AR Sco

Abstract

Marsh et al. (2016) detected radio and optical pulsations from the binary system AR Scorpii (AR Sco). This system, with an orbital period of 3.55 h, is composed of a cool, low-mass M-dwarf and a white dwarf with a spin period of 1.95 min. Buckley et al. (2017) found that the emission from the white dwarf is strongly linearly polarised (up to 40%) with periodically changing intensities. This periodic non-thermal emission is thought to be synchrotron emission (Buckley et al., 2017; Takata et al., 2017) that is powered by the highly magnetised \begin{equation} <> alpha=\left(86.6_{-2.8}^{+3.0}\right)^{\circ} \end{equation} </>Using these observations, I was able to do rst-order spectral calculations to constrain some of the parameters for the system. Lastly, using phase-resolved optical observations, I was able to obtain and at the di erent orbital phases.