SIMBAD references

The constituents of the cosmic IR background (CIB) are studied at its peak wavelengths (100 and 160 µm) by exploiting Herschel/PACS observations of the GOODS-N, Lockman Hole, and COSMOS fields in the PACS evolutionary probe (PEP) guaranteed-time survey. The GOODS-N data reach 3σ depths of ∼3.0mJy at 100µm and ∼5.7mJy at 160µm. At these levels, source densities are 40 and 18 beams/source, respectively, thus hitting the confusion limit at 160µm. Differential number counts extend from a few mJy up to 100-200mJy, and are approximated as a double power law, with the break lying between 5 and 10mJy. The available ancillary information allows us to split number counts into redshift bins. At z≤0.5 we isolate a class of luminous sources (L_IR∼10¹¹L_☉), whose SEDs resemble late-spiral galaxies, peaking at ∼130µm restframe and significantly colder than what is expected on the basis of pre-Herschel models. By integrating number counts over the whole covered flux range, we obtain a surface brightness of 6.36±1.67 and 6.58±1.62[nW/m2/sr] at 100 and 160µm, resolving ∼45% and ∼52% of the CIB, respectively. When stacking 24µm sources, the inferred CIB lies within 1.1σ and 0.5σ from direct measurements in the two bands, and fractions increase to 50% and 75%. Most of this resolved CIB fraction was radiated at z≤1.0, with 160µm sources found at higher redshift than 100µm ones.