Herschel: Science Objectives and Current Status

Abstract

The "Herschel Space Observatory" (formerly known as the "FarInfraRed and Submillimetre Telescope" - FIRST) is thefourth cornerstone mission in the European Space Agency (ESA)science programme. It will perform imaging photometry andspectroscopy in the far infrared and submillimetre part of thespectrum, covering approximately the 57-670 μm range. The key science objectives emphasize current questions connected to the formation of galaxies and stars, however, having unique capabilities in several ways, Herschel will be a facility available to the entire astronomical community. Because Herschel to some extent will be itsown pathfinder, the issue of instrument calibration and dataprocessing timescales has special importance. Herschel will carry a 3.5 metre diameter passively cooled telescope.The science payload complement - two cameras/medium resolutionspectrometers (PACS and SPIRE) and a very high resolution heterodynespectrometer (HIFI) - will be housed in a superfluid heliumcryostat. Herschel will be placed in a transfer trajectory towards its operational orbit around the Earth-Sun L2 pointby an Ariane 5 (shared with the ESA cosmic background mappingmission Planck) in early 2007. Once operational Herschel will offer aminimum of 3 years of routine observations; roughly2/3 of the available observing time is open to the generalastronomical community through a competitive proposalprocedure.