WHITE DWARF MASSES FOR CATACLYSMIC VARIABLES WITH VERY HARD ENERGY SPECTRA

The hard Xrays from accreting white dwarfs (WDs) in magnetic cataclysmicvariables (CVs) are produced by shockheating in the accretion column,and the measured temperature depends on the mass of the WD. By obtaininghighquality hard Xray spectra, it is possible to measure the temperatureand constrain the WD mass. An important question is whether the WD massdistribution extends up to the Chandrasekhar limit. The best place to lookfor highmass WDs is among CVs with the hardest spectra, making CVs foundin the 20100 keV INTEGRAL survey good candidates for having more massiveWDs. We propose NuSTAR and XMM observations of two IGR CVs. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]