Top panel: variation of the absorption coefficient with L for the azimuthal orders m = 0 (dashed line) and m = 1 (solid line). Bottom panel: variation of the absorption coefficient with m at L = 2364. In both panels, asterisks correspond to the simulation with a flux tube with a 170 km radius, diamonds to the flux tube with a 370 km radius, and crosses to the flux tube with a 560 km radius.