Flare-induced changes of the photospheric magnetic field in a $\delta$-spot deduced from ground-based observations

摘要: Aims: Changes of the magnetic field and line-of-sight velocities in photosphere are being reported for an M-class flare that originated at a $\delta$-spot belonging to active region NOAA 11865. Methods: High-resolution ground-based near-infrared spectropolarimetric observations were acquired simultaneously two photospheric spectral lines, Fe I 10783 \AA\ Si 10786 \AA, with Tenerife Infrared Polarimeter Vacuum Tower Telescope (VTT) on 2013 October 15. The covered several stages flare. Inversions full-Stokes vector both lines carried out results put into context using (extreme)-ultraviolet filtergrams from Solar Dynamics Observatory (SDO). Results: showed high flaring activity during whole observing period. After flare, longitudinal did not show significant changes along polarity inversion line (PIL). However, enhancement transverse approximately 550 G was found bridges PIL connects umbrae opposite polarities $\delta$-spot. At same time, newly formed system loops appeared co-spatially corona as seen 171 Atmospheric Imaging Assembly (AIA) board SDO. we cannot exclude connection between already existed upper atmosphere before became visible only later when it filled hot plasma. Doppler persistent upflow pattern without due Conclusions: increase component after together loop support recent predictions models observations.