Main Objective: Plasma flows study inside a Dark Halo by using EIS and IRIS joint observations
Scientific Justification: Solar Active Regions (ARs) are often surrounded by areas appearing less bright than the Quiet Sun (QS), which are called Dark Halos (DHs, Andretta et al. 2014). They were first identified in the chromosphere (Hale & Ellerman, 1903) but with the advent of UV and EUV observations it has been possible to observe regions of reduced emission around ARs also in a wide range of spectral lines originating Transition Region and low corona. DHs are very common solar features, yet we do not fully understand what they are or the physical mechanisms that create and sustain them.
This study will investigate the relationship of DHs with AR upflows/downflows, which has not been done yet. We want to study Doppler shift maps of a DH in order to examine the plasma velocities inside it, by combining Hinode/EIS and IRIS simultaneous observations, that together allow a view of the solar atmosphere from the chromosphere to the corona. |
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