X-rays in intermediate polars ( IPs ) originate in a compact region near the surface of a magnetic white dwarf ( WD ) and interact with the complex environment surrounding the emission region .
Here we report a case study of two IPs , TV Col and V2731 Oph with selected archival X-ray observations ( NuSTAR , Swift , Suzaku , and XMM- Newton ) .
For TV Col , we were successful in simultaneously accounting for the primary X-rays , the secondary X-rays due to Compton scattering and fluorescence , and the effects of local absorbers .
In this case , we were able to demonstrate that the shock height is small , based on the high reflection amplitude , and hence the maximum temperature of the post-shock region can be used to derive the WD mass of 0.735 \pm 0.015 M _ { \odot } .
Despite the high specific accretion rate required to explain the small shock height , we do not detect any spin modulation in our NuSTAR data , consistent with the modest amount of complex absorption seen spectroscopically .
We argue that our results are robust because they are based on the joint temporal-spectral analysis of broadband X-ray data .
The spectrum of V2731 Oph is more highly absorbed .
Through our analysis of the Suzaku data , we present a spectral model with nitrogen overabundance without the previously claimed soft blackbody that should be further explored .
We have been unable to constrain reflection amplitude for V2731 Oph ; this and the detection of spin modulation above 10 keV suggest that it may have a tall shock , hence we only derive a lower limit to the mass of its WD ( > 0.9 M _ { \odot } ) .