Broadband high-frequency waves detected at dipolarization fronts

Abstract

Dipolarization front (DF) is a sharp boundary most probably separating the reconnection jet from the background plasma sheet. So far at this boundary, the observed waves are mainly in low-frequency range (e.g., magnetosonic waves and lower hybrid waves). Few high-frequency waves are observed in this region. In this paper, we report the broadband high-frequency wave emissions at the DF. These waves, having frequencies extending from the electron cyclotron frequency f_ce, up to the electron plasma frequency f_pe, could contribute 10% to the in situ measurement of intermittent energy conversion at the DF layer. Their generation may be attributed to electron beams, which are simultaneously observed at the DF as well.