Images of gradual millimeter emission and multi-wavelength observations ofthe 17 August 1994 solar flare

We present a comprehensive analysis of the 17 August 1994 flare, the first flare imaged at millimeter (86 GHz) wavelengths. The temporal evolution of this flare displays a prominent impulsive peak shortly after 01:02 UT, obse rved in hard X-rays and at microwave frequencies, followed by a gradual dec ay phase. The gradual phase was also detected at 86 GHz. Soft X-ray images show a compact emitting region (less than or similar to 20 "), which is res olved into two sources: a footpoint and a loop top source. Nonthermal emiss ions at microwave and hard X-ray wavelengths are analyzed and the accelerat ed electron spectrum is calculated. This energy spectrum derived from the m icrowave and hard X-ray observations suggests that these emissions were cre ated by the same electron population. The millimeter emission during the gr adual phase is thermal bremsstrahlung originating mostly from the top of th e flaring loop. The soft X-rays and the millimeter flux density from the fo otpoint source are only consistent with the presence of a multi-temperature plasma at the footpoint.