Estimation of the background emission below loop bundle 1 for the EUV emission enhancements measured with slits L1.1 and L1.2 (Figs. 5a and 5b). HRIEUV images of loop bundle 1 show the location of slit L1.1 (a) and L1.2 (c). Background slits, indicated by cyan dotted lines, are obtained by shifting the original slits (dashed white lines) in the Carrington latitude. The time-distance maps along the background slits are shown in panels (b) and (d) for slits L1.1 and L1.2, respectively. The EUV emission enhancements associated with the two slits are not detected in the background emission.