Spatial distribution of the peak main beam temperature (T_mb) of the (1 − 0) line of the CO and HCO⁺ isotopologues as well as of the dust temperature (T_dust), visual extinction (A_V), and the ratio of the far UV field over the visual extinction (G₀/A_V) toward the Horsehead nebula. The used projection is the Azimuthal one rotated by 14° around the center of coordinates RA= 05^h40^m54.27^s, Dec= −02°28′00.00″ in the International Celestial Reference System. Contours of the dust visual extinction at 3, 7, and 16 magnitudes are overlaid on each panel. The crosses and circles show lines of sight that are studied in more detail in this paper (see Table 2 for the corresponding coordinates).