SAFARI : A far - IR imaging spectrometer for SPICA

The far-IR spectral window plays host to a wide range of both spectroscopic and photometric diagnostics with which to open the protoplanetary disks and exoplanet research to wavelengths completely blocked by the Earths atmosphere. These include some of the key atomic (e.g., oxygen) and molecular (e.g., water) cooling lines, the dust thermal emission, the water ice features as well as many other key chemical tracers. Most of these features can not be observed from ground-based telescopes but play a critical diagnostic in a number of key areas including the early stages of planet formation and potentially exoplanets. The proposed Japanese-led IR space telescope SPICA, with its 3.5m cooled mirror will be the next step in sensitivity after Herschel. SPICA has been recently selected to go to the next stage of the ESA’s Cosmic Vision 2015-2025 process. This contribution summarizes the design concept behind SAFARI : an imaging far-IR spectrometer covering the ∼30-210μm waveband that is one of a suite of instruments for SPICA; it also highlights some of the science questions that it will be possible to address in the field of exoplanets and planet formation.