Previous abstract Next abstract
We have constructed semi-empirical loop models that best fit key coronal parameters derived from ROSAT PSPC observations of selected low mass stars. The X-ray pulse-height distributions are represented by two dominant components. These include a soft component that is characterized by compact loop configurations with loop lengths that are one or more orders of magnitude smaller than the stellar radius. By contrast, two types of stable solutions can be found for the hard component, namely very long loops (much larger than a pressure scale height) with large filling factors, and very compact loops with very small filling factors. The ``long" solutions are physically excluded since they violate stability criteria. We identify the ``small" solutions with compact loop flares. The implications of these results for coronal structure and angular momentum evolution in low mass dwarfs will be discussed.
Wednesday program listing