Multi-wavelength observations of compact solar flares

G. Del Zanna

H.E. Mason DAMTP, University of Cambridge, UK

A. Berlicki, B. Schmieder (Observatoire de Paris,Meudon)

Contents

1  Introduction

• The SOHO/Coronal Diagnostic Spectrometer provides essential spectroscopic information to understand the characteristics and dynamics of solar coronal features.
• We give a description of the main observational features and what types of measurements (densities, temperatures, flows) are obtained.
• These provide important observational constraints for flare modeling.
• CDS observations of a compact M1 flare that occurred on October 22 2002, also observed from the ground in chromospheric lines and by RHESSI.

  The flare occurred in a region of strong and mixed magnetic polarity, was compact and lasted only a short time.

1.1  paper

2  Overview

THEMIS observed continuously between 15:41-17:26 UT.

TRACE and VTT/MSDP observations were performed during the whole flare.

VTT/MSDP observations in Ha 9 scans between 15:30 and 16:17 UT

TRACE high cadence (40 s) in the 195 Å band between 15:29 and 15:41 UT

3  Pre-flare

4  Movies!

movie_mdi_long.html movie_mdi_long.mpg

movie_mdi_15_16.html movie_mdi_15_16.mpg

movie_trace.html movie_trace.mpg

5  The M1 flare

5.1  Zoom in

6  Post-flare CDS raster 15:43-17:07 UT

7  Conclusions

• Strong blue-shifts in lines emitted in the 1-8 MK range are observed at the bases of hot Fe XIX structures.
• The hot structures are also clearly visible in the TRACE 195 Å band
• The hot structures match the thermal emission as seen by RHESSI

Acknowledgements

Support from PPARC is acknowledged.