RT Journal Article T1 PACS Evolutionary Probe (PEP) - A Herschel key program A1 Cava, A. A1 Domínguez Sánchez, Helena AB Deep far-infrared photometric surveys studying galaxy evolution and the nature of the cosmic infrared background are a key strength of the Herschel mission. We describe the scientific motivation for the PACS Evolutionary Probe (PEP) guaranteed time key program and its role within the entire set of Herschel surveys, and the field selection that includes popular multiwavelength fields such as GOODS, COSMOS, Lockman Hole, ECDFS, and EGS. We provide an account of the observing strategies and data reduction methods used. An overview of first science results illustrates the potential of PEP in providing calorimetric star formation rates for high-redshift galaxy populations, thus testing and superseding previous extrapolations from other wavelengths, and enabling a wide range of galaxy evolution studies. PB EDP Sciencies SN 0004-6361 YR 2011 FD 2011-08 LK https://hdl.handle.net/20.500.14352/44688 UL https://hdl.handle.net/20.500.14352/44688 LA eng NO © ESO 2011. © EDP Sciences.Artículo firmado por 39 autores. We thank the referee for helpful comments. PACS has been developed by a consortium of institutes led by MPE (Germany) and including UVIE (Austria); KUL, CSL, IMEC (Belgium); CEA, OAMP (France); MPIA (Germany); IFSI, OAP/OAT, OAA/CAISMI, LENS, SISSA (Italy); IAC (Spain). This development has been supported by the funding agencies BMVIT (Austria), ESA-PRODEX (Belgium), CEA/CNES (France), DLR (Germany), ASI (Italy), and CICYT/MCYT (Spain). NO BMVIT (Austria) NO ESA-PRODEX (Belgium) NO CEA/CNES (France) NO DLR (Germany) NO ASI (Italy) NO Comisión Interministerial de Ciencia y Tecnología (CICYT), España NO Ministerio de Ciencia y Tecnología (MCYT), España DS Docta Complutense RD 27 abr 2025