Testing the cooling flow model in magnetic cataclysmic variables

G. J. M. LUNA

Boston

Workshop; 15 Years of Science with Chandra; 2014

Chandra X-ray Center

We use the best available X-ray data from an intermediate polar to study the cooling-flow model often applied to model their X-ray spectra. After deriving the EMD from different models, we calculate line fluxes and H-like to He-like line ratios and compare them with a 496 ks Chandra/HETG observation of the intermediate polar EX Hya. We find that the H/He ratios are not well reproduced by simple isobaric cooling flow models. We discard mechanisms such as photoionization, resonant scattering, and Compton cooling. We are studying thermal conduction, which transfers energy from the region above 10^7.0 K, where the H-like lines are mostly formed, to the cooler region where the He-like ions of the lower-Z elements are formed, so it could help to at least partly resolves the problem.