The Herschel Space Observatory and Belgium

The Herschel Space Observatory will be the first space observatory covering the full far-infrared and submillimetre electromagnetic spectrum.

The satellite consists of three instruments:

HIFI, the Heterodyne Instrument for the Far Infrared, a high-resolution spectrograph that operates in the range of 480 to 1250 GHz in five bands and 1410 to 1910 GHz in two additional bands.

PACS, the Photodetector Array Camera and Spectrometer, a bolometer array photometer and a photoconductor array imaging spectrometer operating at a wavelenght range between 60 and 210 µm.

SPIRE, the Spectral and Photometric Imaging Receiver, consisting of a 3-band imaging photometer and a Imaging Fourier Transform Spectrometer and will operate at wavelengths between 200 and 670 µm.

Herschel will be launched in 2007 together with Planck, another ESA scientific mission. Both satellites will separate shortly after launch and will be operated independently.

With the broad wavelength range of approximately 60 to 670 um, Herschel will observe the so-called `Cold Universe'. Black bodies with temperatures between 5 and 50 K, peak at these wavelengths. Also the brightest molecular and atomic emission lines for gasses with temperatures between 10 and a few hundred Kelvin are emitted in the far-infrared. With its photometric mapping capabilities, Herschel offers the possibility of unbiased surveys related to galaxy and star formation. With the spectroscopic instruments, a characterisation of (newly detected) objects will be possible. Interesting results are to be expected in the field of Cosmology (i.e. discovery of proto-galaxies, formation of Galaxies), interstellar medium (spectroscopic studies of gas and dust) and star formation as well as in the field of our solar system, through the study of comets and planets.

Belgium has a large participation (20%) in the PACS instrument. The principle investigator of PACS is Albrecht Poglitsch from the Max-Planck-Institut für Extraterrestrische Physik (MPE) in Garching, Germany. Prof. Christoffel Waelkens (K.U.Leuven)is co-Principle Investigator of PACS.

The Belgian Institutes involved in the development of the PACS instrument are :

IMEC for the development of the cryogenic read-out circuits for the photoconductors in the spectrometer chain of the instrument.
www.imec.be

Centre Spatial de Liege (CSL) who build the detector- and mechanism control electronics, as well as the spectrometer grating.
www.ulg.ac.be/cslulg

Institute of Astronomy K.U.Leuven who participate in the Instrument Control Center, responsible for the operations and calibration of the instrument prior to launch and during the flight.
www.ster.kuleuven.ac.be

The participation in the development of the PACS instrument gives Belgian astronomers guaranteed access to observing time on the Herschel Space Observatory. To maximise the scientific return of the mission to the Belgian astronomical community, a working group has been set up to define and prepare the Herschel observing programmes in the Belgian Guaranteed Time. This working group consists of astronomers of the Rijksuniversiteit Gent (RUG), the Royal Observatory of Belgium (R.O.B.), the Universite Libre de Bruxelles (ULB), the Universite de Liege (ULG), the Universitaire Instelling Antwerpen (UIA) and the Katholieke Universiteit Leuven (K.U.L.)