A Cryogenic Telescope for Far-Infrared Astrophysics: A Vision for NASA in the 2020 Decade

Many of the transformative processes in the Universe have taken place in regions obscured by dust, and are best studied with far-IR spectroscopy. We present the Cryogenic-Aperture Large Infrared-Submillimeter Telescope Observatory (CALISTO), a 5-meter class, space-borne telescope actively cooled to T∼4 K, emphasizing moderate-resolution spectroscopy in the crucial 35 to 600μm band. CALISTO will enable NASA and the world to study the rise of heavy elements in the Universe’s in the first billion years, chart star formation and black hole growth in dust-obscured galaxies through cosmic time, and conduct a census of forming planetary systems in our region of the Galaxy. CALISTO will capitalize on rapid progress in both format and sensitivity of far-IR detectors. Arrays with a total count of a few ×105 detector pixels will form the heart of a suite of imaging spectrometers in which each detector reaches the photon background limit. The Far-IR Science Interest Group will meet from 3–5 June 20151 with the intention of reaching consensus on the architecture for the Far-IR Surveyor mission. This white paper describes one of the architectures to be considered by the community. One or more companion papers will describe alternative architectures. ∗bradford@caltech.edu 1http://conference.ipac.caltech.edu/firsurveyor/