On the origin of the blue continuum of white-light flares

A new model for white-light flares is proposed in order to explain the observed blue continuum (i.e., the higher contrast longward of the Balmer jump, around 4000 A). Its broad temperature plateau between 60,000 and 90,000 K is compatible with chromospheric evaporation. The predicted UV emission, computed here in the Si IV resonance lines (1402 and 1393 A), is, however, too large by two orders of magnitude, as compared to the emission from weak flares. Because of the lack of a comprehensive set of measurements in white-light flares, the validity of such a model is still open.