White Dwarf Mass Estimation with X-ray Spectroscopy

Takayuki Hayashi
2019 Proceedings of Frontier Research in Astrophysics – III — PoS(FRAPWS2018)   unpublished
X-ray thermal and reflection spectral models of intermediate polars (IPs) are introduced. The thermal model is based on a hydrodynamical calculation for the Post-Shock Accretion Column (PSAC). The total PSAC spectrum is obtained by integrating the spectrum along the PSAC with the calculated plasma parameters. The thermal spectrum is harder with a more massive WD because of its deeper potential. The reflection is modeled by a Monte-Carlo simulation. The PSAC irradiates the cool WD with the
more » ... s thermal X-ray spectra by considering the stratified structure of the PSAC. Basically, the reflection spectrum is harder and more intense relative to the thermal with a more massive WD. The IP spectral models were applied to V1223 Sagittarii and reasonably reproduce its spectrum. The WD mass and accretion rate per unit area (specific accretion rate) were measured to be M WD = 0.92±0.02 M ⊙ and a > 10 0.3 g cm −2 s −1 , respectively.
doi:10.22323/1.331.0057 fatcat:leovouo4pjdmhezk4yyxgdncye