Small-scale impulsive extreme-UV emission enhancements along network loops

Network loops are a common feature in the quiet Sun. The physical processes sustaining their energy budget are still discussed. We relied on a multi-instrumental (Solar Orbiter/EUI, Solar Orbiter/PHI, and IRIS) observation of a six-hour quiet-Sun region to measure the dynamics and the possible magnetic drivers of impulsive Extreme Ultraviolet (EUV) emission enhancements along network loops. We report the detection of small-scale impulsive EUV emission enhancements with EUI/HRIEUV in three network loops. We selected four EUV emission enhancements to measure their plane-of-sky velocities in HRIEUV, their Doppler velocities in the line (log Si iv T = 4.8) with IRIS, and their possible relation to small-scale flux emergence and fluctuation in one of the loop footpoints. The plane-of-sky velocities of the four EUV emission enhancements have a component that seems to appear almost instantaneously along the loop (≥ ), and two of them had a co-temporal component with a plane-of-sky velocity of up to , starting near one of the loop footpoints. In one case, we measured a co-temporal intensity increase in the line with IRIS that is associated with Doppler velocities down to and up to along the line of sight. Finally, we measured cases of small-scale (≈ ) mixed-polarity field emergence and fluctuation near one of the loop footpoints. 220 įlo separate-uncertainty = true 77(19) įlo Si iv -32 įlo 18 įlo 8e16 We conclude that the fast components on the plane-of-sky are consistent with a thermal transfer or supersonic plasma flows, while the slower component is consistent with plasma flows. A possible physical origin for these EUV emission enhancements would be magnetic reconnection driven by either a photospheric motion of the loop footpoints or by the reconnection of the loop with small-scale magnetic bipoles.