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تسجيل مستخدم جديدIRIS observations of the low-atmosphere counterparts of active region outflows
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Active region (AR) outflows have been studied in detail since the launch of textit{Hinode}/EIS and are believed to provide a possible source of mass and energy to the slow solar wind. In this work, we investigate the lower atmospheric counterpart of AR outflows using observations from the textit{Interface Region Imaging Spectrograph} (textit{IRIS}). We find that the textit{IRIS} siiv, cii and mgii transition region (TR) and chromospheric lines exhibit different spectral features in the outflows as compared to neighboring regions at the footpoints (moss) of hot AR loops. The average redshift of siiv in the outflows region ($approx$ 5.5~km s$^{-1}$) is smaller than typical moss ($approx$ 12--13 km~s$^{-1}$) and quiet Sun ($approx$ 7.5 km~s$^{-1}$) values, while the cii~line is blueshifted ($approx$ -1.1--1.5 km~s$^{-1}$), in contrast to the moss where it is observed to be redshifted by about $approx$ 2.5 km~s$^{-1}$. Further, we observe that the low atmosphere underneath the coronal outflows is highly structured, with the presence of blueshifts in siiv and positive mgii k2 asymmetries (which can be interpreted as signatures of chromospheric upflows) which are mostly not observed in the moss. These observations show a clear correlation between the coronal outflows and the chromosphere and TR underneath, which has not been shown before. Our work strongly suggests that these regions are not separate environments and should be treated together, and that current leading theories of AR outflows, such as the interchange reconnection model, need to take into account the dynamics of the low atmosphere.
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