An Empirical Correlation of T max–M WD of Dwarf Novae and the Average White Dwarf Mass in Cataclysmic Variables in the Galactic Bulge

Zhuo-li Yu, Xiao-jie Xu, Xiang-Dong Li, Tong Bao, Ying-xi Li, Yu-chen Xing, Yu-fu Shen
2018 Astrophysical Journal  
The mean white dwarf (WD) mass in the Galactic bulge cataclysmic variables (CVs) was measured by applying the the shock temperature-WD mass correlation of magnetic cataclysmic variables (mCVs) to the Galactic Bulge X-ray Emission (GBXE) spectra. However, the resulting mean WD mass is lower than that of the local CVs. This discrepancy could be explained by the dominating sources in the GBXE are non-mCVs instead of mCVs. In this work, we conduct an thorough investigation on the X-ray spectra of
more » ... cal DNe from archives, and derive semi-empirical correlations between the shock temperature T_ max, the flux ratio of to lines, and WD mass for quiescent, non-magnetic CVs. By applying these correlations to the GBXE, we derive the average WD mass of CVs in the Galactic bulge to be 0.81± 0.07M_. This value is consistent with previous optical measurements of WD mass in local CVs.
doi:10.3847/1538-4357/aaa47d fatcat:tqmm6vo6g5eulevwol4trlayqq