Seismic waves from the solar flares of 2003 October 28 and 29

We report the detection of seismic waves emitted from powerful solar flares that occurred in NOAA Active Region 10486 on 2003 October 28 and 29. We used helioseismic holography to image seismic sources of the waves. This technique was previously used to image seismic emission discovered by Kosovichev and Zharkova from the large solar flare of 1996 July 9. Egression power maps at 6 mHz with a 2 mHz bandwidth reveal extended acoustic sources strongly associated with the footpoints of the coronal loops that hosted the flares. The acoustic signatures are co-aligned with the RHESSI hard X-ray contours suggesting a direct link between energetic particles accelerated during the flare and the hydrodynamic response of the chromosphere to these particles at the footpoints of the loop.