4th Gamow International Conference on Astrophysics and Cosmology after Gamow/9th Gamow Summer School, Odesa, Ukraine, 17 - 23 August 2009, vol.1206, pp.462-463
In this study, a spectral analysis of the dwarf nova WX Hyi (which is a Cataclysmic Variables (CV)) is presented. The system was observed during the normal ourburst with the XMM-Newton observatory. X-ray bolometric flux value (E-x <= 12 keV) is estimated to be similar to 2.98 x 10(-12) erg cm(-2) s(-1) and X-ray luminosity L-x= 5 x 10(31) erg / s. Elemental abundance was founded 3 factor of solar abundances. If the gas temperature is higher than 10(7)K, it is optically thin. Therefore, they are radiated as thermal bremsstrahlung X-ray emission. PN+MOS detector measurements indicate that X-ray emitting maximum plasma temperature is kT(Max),= 31.3 keV (3.6322 x 10(8) K). Hence, the X-ray spectrum analysis during the normal outburst of WX Hyi is indicated a hot and optically thin plasma in the boundary layer that cools via an isobaric cooling flow while settling onto the white dwarf. For this temperature, the mass accretion rate is estimated to be (M) over dot(BL)= 4 x 10(14) gr / s (6.3 x 10-12 M-circle dot/yr). The ratio of the Boundary Layer (BL) (X-ray) luminosity to the disc luminosity was estimated to be L-BL / L-disc similar to 0.3. We calculated the mass accretion ratio of BL to the accretion disc ((M) over dot(BL)/(M) over dot(disc)) to be similar to 0.74 and similar to 0.27 during the rise to the outburst and outburst, respectively. A great quantity of the accreting gas from the rise to the outburst is lost in a wind. Fe XXV line at 6.7 keV is originated from a plasma having temperature of 10(7) - 10(8) K. The obtained temperature value from this study is compatible with this plasma structure.