A microflare with hard X-ray-correlated gyroresonance line emission at 314 MHz

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

3

Sun: Corona, Magnetic Fields, Sun: Flares, Sun: Radio Radiation, Sun: X-Rays, Gamma Rays

Scientific paper

Context. Small energy release events in the solar corona can give insights into the flare process which are regularly hidden in the complex morphology of larger events. For one case we find a narrowband radio signal well correlated with the hard X-ray flare. We investigate wether these signals are probes for the flare current sheet. Aims: We aim to establish the relation between narrowband and short-duration features (<1% of the observing frequency in the spectral range 250-340 MHz, and some 5 s until 2 min, respectively) in dynamic radio spectral diagrams and simultaneously occuring HXR bursts. Methods: We use dynamic radio spectra from the Astrophysical Institute Potsdam, HXR images of RHESSI, TRACE coronal and chromospheric images, SOHO-MDI high resolution magnetogram data, and its potential field extrapolation for the analysis of one small flare event in AR10465 on September 26, 2003. We point to similar effects in e.g. the X-class flare on November 03, 2003 to demonstrate that we are not dealing with a singular phenomenon. Results: We confirm the solar origin of the extremely narrowband radio emission. From RHESSI images and the magnetic field data we identify the probable site of the radio source as well as the HXR footpoint and the SXR flare loop emission. The flare loop is included in an ongoing change of magnetic connectivity as confirmed by TRACE images of hot coronal loops. The flare energy is stored in the nonpotential magnetic field substructure around the microflare site which is relaxed to a potential one. Conclusions: We conclude that the correlated HXR footpoint/narrowband radio emission, and the transition to a second energy release in HXR without associated radio emission are direct probes of changing magnetic connectivity during the flare. We suppose that the narrowband radio emission is due to gyroresonance radiation at the second harmonic of the local electron cyclotron frequency. It follows an upper limit of the magnetic field in the radio source volume of less than 50% of the mean potential field in the same height range. This supports the idea that the narrowband radio source is situated in the immediate surroundings of the flare current sheet.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

A microflare with hard X-ray-correlated gyroresonance line emission at 314 MHz does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with A microflare with hard X-ray-correlated gyroresonance line emission at 314 MHz, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A microflare with hard X-ray-correlated gyroresonance line emission at 314 MHz will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1344067

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.