Abstract
Provisional results are presented for three gradual microwave bursts.
Observations were made
with the Nobeyama Radioheliograph at 17 GHz
and simultaneously with the
Yohkoh /Soft X-ray
Telescope with partial coverage in time as well as radiometers at
Nobeyama and Toyokawa. 1993
March 23 flare shows a cusp-type structure in soft X-ray images in late
phase, where the 17GHz
images show weak emission in gradual phase. This new discovery is
explained in terms of a
simple model of trapped electrons in a weak field.