Flare-induced Sunquake Signatures in the Ultraviolet as Observed by the Atmospheric Imaging Assembly

Abstract

Abstract Sunquakes (SQs) have been routinely observed in the solar photosphere, but it is only recently that signatures of these events have been detected in the chromosphere. We investigate whether signatures of SQs are common in ultraviolet (UV) continua that sample the solar plasma several hundred km above where SQs are typically detected. We analyze observations from the Solar Dynamics Observatory’s Atmospheric Imaging Assembly (SDO/AIA) 1600 and 1700 Å passbands, for SQ signatures induced by the flares of Solar Cycle 24. We base our analysis on the 62 SQs detected in the recent statistical study presented by Sharykin & Kosovichev. We find that 9 out of 62 SQ candidates produced a response that is clearly detected in running-difference images from the AIA 1600 and 1700 Å channels. A binary frequency filter with a width of 2 mHz, centered on 6 mHz, was applied to the data. The first signature of each SQ was detected at distances between 5.2 and 25.7 Mm from the associated flare ribbon. Time–distance and regression analysis allowed us to calculate the apparent transverse velocities of the SQs in the UV data sets and found maximum velocities as high as 41 km s−1, 87 Mm away from the SQ source. Our analysis shows that flare-induced SQ signatures can be detected in the SDO/AIA 1600 and 1700 Å passbands, hinting at their presence in the lower chromosphere. There was no apparent correlation between GOES flare classification and the appearance of the SQ at these heights.