2010MNRAS.408.2298B

We have derived an X-ray luminosity function using parallax-based distance measurements of a set of 12 dwarf novae, consisting of Suzaku, XMM-Newton and ASCA observations. The shape of the X-ray luminosity function obtained is the most accurate to date, and the luminosities of our sample are concentrated between ∼10³⁰ and 10³¹ erg/s, lower than previous measurements of X-ray luminosity functions of dwarf novae. Based on the integrated X-ray luminosity function, the sample becomes more incomplete below ∼3x10³⁰erg/s than it is above this luminosity limit, and the sample is dominated by X-ray bright dwarf novae. The total integrated luminosity within a radius of 200 pc is 1.48x10³² erg/s over the luminosity range of 1x10²⁸ erg/s and the maximum luminosity of the sample (1.50x10³² erg/s). The total absolute lower limit for the normalized luminosity per solar mass is 1.81x10²⁶ erg/s/M_☉ which accounts for ∼16 per cent of the total X-ray emissivity of cataclysmic variables as estimated by Sazonov et al.