# Presentation: 037914

## Radio and Hard X-Ray Imaging Observations of the M 5.7 Flare of2002 March 14

- E.J. Schmahl1,2, M.R. Kundu1, and V.I. Garaimov1

- 1Astronomy Department, University of Maryland, College Park, MD 20742

- 2Lab for Solar and Space Physics, NASA Goddard Space Flight Center, Greenbelt, MD 20771

- 1

## Abstract

- The former is the main flare  site where we observe microwave, HXR, and EUV emissions.  In HXR there are two main identifiable loop  systems, an elongated one filled with energetic electrons primarily  emitting lower energy (12-25 keV) HXR with a co-located microwave  source; this source has distinct foot points at higher X-ray  energies. The second loop system is implied by compact HXR sources  in opposite magnetic polarities separated by a distance greater than
-   the length of the first loop system.  Spectroscopic analysis of the  RHESSI data hows that the spectrum can be fitted with a  thick-target model with a thermal component and a broken power-law  component of the electron energy distribution. This model isused to address the thermal/nonthermal and radio/HXR number problems.

- We describe a flare of GOES class 5.7 which was observed simultaneously by RHESSI and NoRH. The flare occurred in active region AR 9866 located near disk center. The hard X-ray, microwave, EIT and TRACE 195 A observations indicate that the flaring region consisted of a complex of multiple loops. In the microwave domain the source morphology, the timing, the polarization characteristics, and the photospheric magnetic fields indicate clearly that it is of a class characterized as a ``double loop'' configuration, meaning two systems of magnetic flux, each consisting of many smaller loops.

- The observations suggest the existence of a small loop system created by the emergence of new flux, which  interacts with an old flux system and of a remote flare site which is observed primarily in radio. The former is the main flare site where we observe microwave, HXR, and EUV emissions.
- In HXR there are two main identifiable loop systems,
- an elongated one filled with energetic electrons primarily  emitting lower energy (12-25 keV) HXR with a co-located microwave  source; this source has distinct foot points at higher X-ray  energies.
- The second loop system is implied by compact HXR sources  in opposite magnetic polarities separated by a distance greater than  the length of the first loop system.
- Spectroscopic analysis of the  RHESSI data shows that the spectrum can be fitted with a  thick-target model with a thermal component and a broken power-law  component of the electron energy distribution. This model is used to address the thermal/nonthermal and radio/HXR number problems.

## INTRODUCTION

## OBSERVATIONS

## RHESSI HARD X-RAY OBSERVATIONS 

## RHESSI Maps

## RHESSI & TRACE

## Slide 9

## NORH RADIO OBSERVATIONS

## 17 GHz & TRACE

## FLARE & REMOTE SOURCE

## REMOTE SOURCE

- 6b

## TRACE and V 17 Ghz

## RHESSI & 17 Ghz I on MDI

- Fig 8

## RHESSI, TRACE & 17 Ghz I

- Fig 10

## Time Profiles, Main & Remote Sources

## 17 & 34 Ghz Profiles

## E & W Profiles Compared

## HARD X-RAY SPECTROSCOPY – RHESSI SPECTRA

## SPECTRAL PARAMETERS

## DISCUSSION

## CONCLUSIONS