出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：The cosmic infrared background (CIB) is studied taking advantage of the PACS 70, 100, 160 mm observations of the GOODS-N, GOODS-S, Lockman Hole and COSMOS fields, belonging to the PACS Evolutionary Probe (PEP) survey. We produce number counts covering more than two orders of magnitude in flux, from ∼1 mJy to few hundreds mJy. Stacking of 24 mm sources and P(D) statistics extend the analysis down to the sub-mJy regime. The available ancillary information allows number counts to be split into redshift bins. At z ≤ 0.5 we isolate a class of luminous IR galaxies (LIR ∼1011 L⊙), whose SEDs peak at∼130 mmrestframe, thus significantly colder than what is expected on the basis of the local luminosity-temperature relation. The integral of number counts provides an estimate of the CIB surface brightness of n In = 3.61±1.12, 8.04± 1.39 and 8.84±1.11 [nW m−2 sr−1] at 70, 100, and 160 mm, respectively. These correspond to 56±10% and 70±9% of the direct CIB measurements at 100 and 160 mm. Employing the P(D) analysis, these fractions increase to ∼60% and ∼82%. Most of this resolved CIB fraction was radiated at z ≤ 1.0, with redder sources lying at higher redshift than blue ones.
