Evolution of small-scale magnetic fields from combined adaptive optics and phase-diverse speckle imaging


We have obtained movies of the photospheric magnetic field at a sustained resolution of 0.2 arcsec by combining the adaptive optics system at the Dunn Solar Telescope with the Zurich Imaging Polarimeter I (ZIMPOL) and processing the data with Phase-Diverse Speckle Imaging and speckle deconvolution. The adaptive optics was correcting the low-order aberrations with an update rate of about 1.5 kHz and fed a narrow-band channel through the Universal Birefringent Filter in the wing of the CaI 610.3 nm line and two white-light channels that were used to obtain one in-focus and one out-of-focus image for the phase- diversity processing, which removes the remaining aberrations. All three channels were equipped with ZIMPOL I cameras running simultaneously at 5 frames per second. The narrow-band intensity and magnetogram images were reconstructed using speckle deconvolution. This combined attack to obtain the best magnetogram movies of the solar surface was very successful and led to spectacular time sequences with a consistent spatial resolution of better than 0.2 arcsec. We will present the first scientific results on the evolution of the small-scale magnetic fields in an active region. This work was supported by the National Science Foundation.

AAS/Solar Physics Division Meeting #31