Small-Scale Magnetic Features in the Active Region NOAA 11024

Abstract

To reveal and study magnetic features in the active region NOAA 11024, temporal changes in the profiles of the Stokes parameter V of photospheric lines Fe I λ 630.15 nm, Fe I λ 630.25 nm, Fe I λ 630.35 nm, and Ti I λ 630.38 nm were analyzed. Data of spectropolarimetric observations carried out with a high temporal and spatial resolution at the French-Italian solar telescope THEMIS (Tenerife Island, Spain) on July 4, 2009, were used. The examined area of the active region includes two pores of opposite polarity and two plages. One of the pores was rapidly developing. For 20 minutes of observations, eruptive processes, such as three Ellerman bombs and chromospheric surges, took place in this area. The V profiles of the photospheric lines substantially differ in different places of the active region. They are normal in most cases. In the pores, their amplitude increases toward outer edges of the pores. The maximum amplitude was noticed in the profiles at the boundary between the emerging pore and the Ellerman bomb. It was rapidly increasing with time. Two small patches with abnormal V profiles of the photospheric lines Fe I λ 630.15 and 630.25 nm have been found. The amplitude of the profiles in these patches was reduced. The amplitude and the shape of the profiles changed with time. One of the patches was between the pores, while the other was in the plage area. During the observations, the polarity of the photospheric magnetic field in these patches changed. Evidence of new, emerging, small-scale magnetic fluxes of opposite polarity was obtained. Due to the emergence of these fluxes, magnetic reconnections started and chromospheric surges and an Ellerman bomb appeared. It has been found that there are strong oscillations in the amplitude of the V profiles of photospheric lines Fe I λ 630.15 and 630.25 nm during Ellerman bombs, which may indicate the pulsed energy realize.