Spatial distribution of the peak periods from the global power spectra of Doppler velocity oscillations. The major periods T_PEAK (in min) are shown for a) Fe i 630.15 nm; b) Fe i 617.3 nm (HMI); and c) Na i 589.6 nm. The scale ranges from 2.5 min (dark blue) to 8 min (dark red). The black contours mark the umbral and penumbral boundaries in continuum intensity. The white arrow is pointing to the disk center.