Measurement of the extragalactic infrared background radiation Part 3.

scientific abstract infrared background radiation carries information from the otherwise unobserv able dark ages of the universe between the redshifts 4 and 1000, during which e.g. the formation of galaxies has taken place. the sensitivity of isophot is sufficient for its detection both in the near and the farir cosmological windows; as compared with the cobe/dirbe experiment the smaller field of view of isophot (3. vs. 0.7 deg) offers several advantages for the disentanglement of the foreground components,i.e. the zodiacal emission,the galactic starlight and the interstellar cirrus. observation summary 1.mapping at 180 microns (9.62 h): we have chosen 13 fields along an arc from the north ecliptic pole to the plane. mapping with c200 in the 180 micron filter aims at (1)finding the darkest (cirrusfree) spots in each field; (2)establishing an accurate link to the cobe/dirbe measurements and facilitates supressing the remaining cirrus contribution from the dirbe measurements; (3)finding the ebl fluctuations due to faint galaxies. raster mapping, aot p22, 180 arc sec spacing. map sizes, integration times, and s/n for a flux of 1 mjy/sr (after subtraction of a zodiacal foreground of 0.5 mjy/sr): field raster size area int.time s/n total time (frames) (arc.min) (sec) (hours) lockmanhole 15 x 15 45 x 45 32 82 3.14 ngphole 15 x 15 45 x 45 16 58 2.14 12 other fields 4 x 12 12 x 36 10 46 4.34 in the first two maps absolute photometry along one strip will be performed, in addition, in order to bind together the legs of the maps; aot p25, c200, 180 micron filter, 32 sec truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]