PIXON-BASED MULTIRESOLUTION IMAGE RECONSTRUCTION FOR YOHKOH'S HARD X-RAY TELESCOPE

Thomas R. Metcalf, Hugh S. Hudson
Institute for Astronomy, University of Hawaii

Takeo Kosugi
National Astronomical Observatory of Japan

R. C. Puetter, R. K. Piña
Center for Astrophysics and Space Sciences, University of California, San Diego

To appear in the Proceedings of the MaxEnt95 Workshop

We present results from the application of pixon-based multiresolution image reconstruction to data from Yohkoh's Hard X-ray Telescope. The goal of the pixon algorithm is to minimize the number of degrees of freedom used to describe an image within the accuracy allowed by the noise. This leads to a reconstruction which is optimally constrained. We apply the pixon code to two solar flares in the HXT database and compare the results of the pixon reconstruction to the results of a direct, linear, smoothed inversion of the HXT Fourier synthesis data and to a maximum entropy reconstruction. The maximum entropy reconstruction is vastly better than the direct inversion, but the pixon reconstruction gives superior noise suppression and photometry. Further, the pixon reconstruction does not suffer from over-resolution of the images.