SIMBAD references

In this paper we present a model of a magnetic loop in an RS CVn active star, in which nonthermal particles are episodically injected in the local thermal plasma. The main parameters of the loop, starspot dimension and maximum photospheric field, are derived from optical observations, while the thermal plasma density is left as a free parameter. It is shown that the computed radio emission, at different times after the injection, reproduces very well the observed common characteristics of the radio spectra observed at different epochs. The agreement with the observations, however, can be achieved only if the thermal plasma density is lower than 10⁷cm^–3. The calculations also show that the structure of the radio source evolves with time from a core-halo to a halo type in agreement with different VLBI observations. The emission measure, derived from the loop's volume and the above mentioned upper limit of thermal plasma density, is in agreement with those inferred from the X-ray observations of these type of stars, indicating a possible co-spatiality of the two emissions.