THE ROSAT ALL-SKY SURVEY OF ACTIVE BINARY CORONAE .2. CORONAL TEMPERATURES OF THE RS CANUM-VENATICORUM SYSTEMS

We present the results from an analysis of X-ray spectra of 44 RS CVn systems obtained during the ROSAT All-Sky Survey with the Position Sensitive Proportional Counter (PSPC). Thermal plasma models with two temperature components are found to reproduce the observations better than single or continuous temperature models. We typically find that a bimodal distribution of temperatures centered near 2 x 10(6) and 1.6 x 10(7) K fit the data best. We show that the PSPC temperatures agree well with those from similar low-resolution measurements, although differences exist, primarily due to differing detector bandpasses. After comparing coronal characteristics-temperature or emission measure-with stellar parameters including rotation period and dynamo number, we find no compelling relationship. Including a gravity term, as suggested by previous investigators, leads to a deceptive relationship, because gravity is a strong function of rotation period for these systems. Similarly, the height integrated emission measures of the components in the two-temperature models, including a gravity term, are found to be well correlated with temperature.