Abstract

The far infrared and submillimetre spectral region is critical to the characterisation of the obscured Universe, both in our own and nearby galaxies and at high redshift. The Herschel Space Observatory, which is currently operating, has a passively cooled 3.5-m diameter telescope and three scientific instruments which are carrying out sensitive imaging and spectroscopy at wavelengths between 55 and 671 microns. I will describe the design and scientific capabilities of Herschel and review some of its early results.

For a comprehensive understanding of the interstellar medium in galaxies over cosmic time, and the relationship between AGN and their host galaxies, future space-borne observations will be needed with much improved sensitivity and angular resolution in the far infrared. The Japanese-led Space Infrared telescope for Cosmology and Astrophysics (SPICA) will be the next major far infrared space astronomy mission. It will carry a 3.2-m telescope cooled to ~ 6 K by mechanical coolers, and a suite of instruments covering the 5 – 200 micron range. The cold aperture will lead to a huge increase in sensitivity over current far infrared facilities. SPICA ’s far infrared camera and spectrometer, SAFARI , will cover the wavelength range between 30 and 200 microns with an observing speed orders of magnitude faster than that achieved by Herschel. I will outline how SPICA ’s capabilities will bring about a major advance in our ability to investigate the extragalactic Universe