Herschel: Science Objectives and Current Status

ESA Astrophysics Missions Div, Research and Scientific Support Dept, ESTEC/SCI-SA, Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands;

Corresponding author: GPilbratt@rssd.esa.int

Abstract

The "Herschel Space Observatory" (formerly known as the "Far InfraRed and Submillimetre Telescope" - FIRST) is the fourth cornerstone mission in the European Space Agency (ESA) science programme. It will perform imaging photometry and spectroscopy in the far infrared and submillimetre part of the spectrum, 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 its own pathfinder, the issue of instrument calibration and data processing timescales has special importance. Herschel will carry a 3.5 metre diameter passively cooled telescope. The science payload complement - two cameras/medium resolution spectrometers (PACS and SPIRE) and a very high resolution heterodyne spectrometer (HIFI) - will be housed in a superfluid helium cryostat. Herschel will be placed in a transfer trajectory towards its operational orbit around the Earth-Sun L2 point by an Ariane 5 (shared with the ESA cosmic background mapping mission Planck) in early 2007. Once operational Herschel will offer a minimum of 3 years of routine observations; roughly 2/3 of the available observing time is open to the general astronomical community through a competitive proposal procedure.