The solar coronal origin of a slowly drifting decimetric-metric pulsation structure

¹ Mullard Space Science Laboratory, University College London, Holmbury Saint Mary, Dorking, Surrey, RH5 6NT, UK
² Institute of Space & Astronautical Science, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510, Japan
³ Observatoire de Paris, Section de Meudon, DASOP, LPSH, UMR 8645 du CNRS, 5 place Jules Janssen, 92195 Meudon Cedex, France
⁴ Institute of Astronomy, ETH Zentrum, 8092 Zürich, Switzerland
⁵ Paul Scherrer Institute, 5232 Villigen PSI, Switzerland

Corresponding author: J. I. Khan, jkhan@spd.aas.org

Received: 6 December 2001
Accepted: 12 March 2002

Abstract

We report observations associated with a short duration, slowly drifting decimetric-metric pulsation structure seen by the Phoenix-2 Radio Spectrometer on 2000 August 25. The range of frequencies over which this drifting radio feature occurred included frequencies observed by the Nançay Radioheliograph enabling the spatial location and development of such a radio source to be determined for the first time. The radio feature was closely associated with a solar flare. This flare was observed by the Yohkoh Soft X-ray Telescope (SXT) allowing us to compare the radio locations with the development of coronal structures seen in soft X-rays. The Yohkoh SXT images reveal two main soft X-ray features: a small flaring kernel region consisting of one or more bright loops located low in the corona and much fainter soft X-ray ejecta observed above the flare kernel region. The radio sources of the drifting pulsation structure moved outward with the soft X-ray ejecta. Our results indicate that the drifting decimetric-metric burst for this event was closely associated with the soft X-ray ejecta.