http://arxiv.org/abs/1908.05132
Numerous apparent signatures of magnetic reconnection have been reported in the solar photosphere, including inverted-Y shaped jets. The reconnection at these sites is expected to cause localised bi-directional flows and extended shock waves; however, these signatures are rarely observed as extremely high spatial-resolution data are required. Here, we use H-alpha imaging data sampled by the Swedish Solar Telescope’s CRisp Imaging SpectroPolarimeter to investigate whether bi-directional flows can be detected within inverted-Y shaped jets near the solar limb. These jets are apparent in the H-alpha line wings, while no signature of either jet is observed in the H-alpha line core, implying reconnection took place below the chromospheric canopy. Asymmetries in the H-alpha line profiles along the legs of the jets indicate the presence of bi-directional flows, consistent with cartoon models of reconnection in chromospheric anemone jets. These asymmetries are present for over two minutes, longer than the lifetimes of Rapid Blue Excursions, and beyond \pm 1 \AA\ into the wings of the line indicating that flows within the inverted-Y shaped jets are responsible for the imbalance in the profiles, rather than motions in the foreground. Additionally, surges form following the occurrence of the inverted-Y shaped jets. This surge formation is consistent with models which suggest such events could be caused by the propagation of shock waves from reconnection sites in the photosphere to the upper atmosphere. Overall, our results provide evidence that magnetic reconnection in the photosphere can cause bi-directional flows within inverted-Y shaped jets and could be the driver of surges.
C. Nelson, N. Freij, S. Bennett, et. al.
Thu, 15 Aug 19
36/69
Comments: 9 pages, 7 figures, accepted for publication in ApJ