W28 F: map of the main-beam brightness temperature of the CH₃OH (J = 6₀–5₀ A⁺) transition integrated over the LSR velocity range from −10 to 25 km s⁻¹. The contour values are at three, five, seven and nine times the rms noise level, which is 0.36 K km s⁻¹. Overlaid we have the OH maser positions (black filled squares) from Claussen et al. (1997) that are located inside the field of view. The large and small circles (30″ and 16″ diameter) represent the FWHM beam width of the APEX telescope at our lowest and highest observing frequency (213 and 374 GHz, respectively). The beams are centered on the methanol peak position (see text) toward which we performed our long integrations.