| Abstract * |
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Active region 12673 produced a number of solar flares in September 2017, including an X9.3 and an X2.2 on September 6th. Our analysis of the Ca II 8542 Å observations for the X9.3 flare led to the first detection of a chromospheric response to a flare induced sunquake. We found that these responses were created by upflows, as revealed by blue asymmetries in the line profiles, and LOS velocities of ~3.2 kms-1. These upflows were found to be co-spatial and co-temporal with HMI LOS sunquake signatures. Following these detections, we examined the X2.2 flare and have identified two more sunquake signatures in the chromosphere. Similar to the X9.3 flare, these responses were created by upflows however, with much slower LOS velocities of ~0.69 kms-1. The line profiles of these upflows were also blue asymmetric. The HMI LOS observations of this flare show extremely short-lived responses in the photosphere, as opposed to the longer more evolved photospheric signatures in the X9.3 flare. Our high-resolution SST observations show that sunquake signatures in the chromosphere are more common than previously thought. The lack of previous detections has been most likely due to the low spatial and temporal resolutions of earlier investigations. In this presentation, I will describe the analysis of these chromospheric responses, as well as the use of the spectroscopic capabilities of the SST in investigating the line profiles of the chromospheric wavefronts created by the sunquakes. |
