Exploratory X-ray Observations of Quiescent Recurrent Novae in CVs

For a binary to be a recurrent nova (RN), it must contain a massive white dwarfnear the Chandrasekhar limit, making it a candidate progenitor of type Iasupernova. The symbiotic RN, T CrB, is now known to be a virgul10^34 erg/s hard Xraysource. While we have initiated a program of pointed Xray observations ofsymbiotic RN systems, other RNe are in cataclysmic variable (CV) systems with aRochelobe filling mass donor. Because we believe that the high Xraytemperature and luminosity seen in T CrB are due to the high mass of the whitedwarf, we expect that there are additional Xray luminous objects among CV RNe.We propose to test this prediction by observing 4 such objects (V394 CrA, CIAql, IM Nor and U Sco) in quiescence with XMMNewton. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]