Studying the decay phase of a short-lived active region with coordinated DST/IBIS, Hinode/EIS+SOT+XRT, SOHO/MDI and TRACE observations

This study concerns the physical processes occurring during the decay phase of the short-lived active region NOAA 10977, as evaluated from analysis of data gathered using ground- (DST/IBIS) and space-based (Hinode/EIS+SOT+XRT, SOHO/MDI and TRACE) facilities. The coordinated observing campaign was performed from December 1st to 9th, 2007, covering several spectral ranges, with unprecedented spatial and spectral resolution. We present preliminary results of the Doppler analysis of plasma motions evaluated from monochromatic images taken along the Ca II (8542 Å) and the Fe I (7049 Å) spectral lines with IBIS. We also report results concerning the horizontal displacements of photospheric magnetic structures and advection flows as obtained from application of Local Correlation Tracking (LCT) and Two-Level Structure Tracking (TST) techniques to both the LoS magnetograms taken by MDI and to high resolution intensity maps obtained by IBIS at DST/NSO.

Further contributions to understanding the mechanisms at the base of the magnetic field diffusion are provided from the inversion of the Stokes profiles of the photospheric Fe I lines at 6301.5 Å and 6302.5 Å, obtained with SOT/SP, and the analysis of filtergrams in the core of the Ca II H line (3968.5 ± 3 Å) and images in G-band (4305 ± 8 Å) taken by SOT/BFI, as well as EIS data and images taken by the thin Be of XRT, and by TRACE at 171 Å and 1600 Å.