Top: color coded brightness temperature distribution for the filamentary structure in the Horologium field at v_LSR = −16.6 km s^-1. The white isophotes display the USM temperatures at the same velocity. Bottom: the brightness temperature distribution at v_LSR = −11.5 km s^-1 is shown in color, the white isophotes are USM temperatures at the same velocity while black isophotes are at v_LSR = −16.6 km s^-1 for comparison with the top panel. Isophote levels are 1, 2.5, and 5 K Galactic coordinates are used, the black lines indicate longitudes of the velocity-position plots in Fig. D.2.