Herschel Space Observatory

The European Space Agency's Herschel Space Observatory (formerly called Far Infrared and Sub-millimetre Telescope or FIRST) has the largest mirror ever built for a space telescope. At 3.5-metres in diameter the mirror will collect long-wavelength radiation from some of the coldest and most distant objects in the Universe. In addition, Herschel will be the only space observatory to cover a spectral range from the far infrared to sub-millimetre.

Mission Objectives

ESA's Herschel mission has been designed to unveil a face of the early Universe that has remained hidden until now. Thanks to its ability to detect radiation at far infrared and sub-millimetre wavelengths, Herschel will be able to observe dust obscured and cold objects that are invisible to other telescopes. Herschel's major objective will be discovering how the first galaxies formed and how they evolved to give rise to present day galaxies like our own. Additional targets for Herschel will include clouds of gas and dust where new stars are being born, disks out of which planets may form and cometary atmospheres packed with complex organic molecules.

Spacecraft:

Mass	3300 kg at launch
Dimensions	9m high, 4m x 4m overall cross section
Launcher	Ariane-5 from Guiana Space Centre
Launch Date	July 2008
Mission Lifetime	3 years nominal from end of commissioning phase
Wavelength	Infrared: 60 to 670 µm

Instruments Aboard Herschel:

• HIFI (Heterodyne Instrument for the Far Infrared) - A very high resolution heterodyne spectrometer
• PACS (Photodetector Array Camera and Spectrometer) - Imaging photometer / medium resolution grating spectrometer
• SPIRE (Spectral and Photometric Imaging Receiver) - Imaging photometer / imaging Fourier transform spectrometer
  

Orbit:

Herschel will launch on an Ariane-5 rocket together with ESA's Planck spacecraft. The two spacecraft will separate after launch and be directly injected towards the second Lagrange point of the Sun-Earth system. Between four and six months after launch, Herschel will be injected into a Lissajous orbit around the L2 point at a distance of around 1.5 million km from Earth.

The University of Calgary's Role in the Herschel Space Observatory:

Dr. Rene Plume is one of the scientists on the Canadian Science Steering Committee for the HIFI instrument aboard Herschel. As such, he has helped to define Canada's main science goals for this instrument which will be accomplished during guaranteed time (a block of time allocated to each contributing nation).

In guaranteed time, Dr. Plume will be leading a project to obtain a complete census of all molecular species in the Orion S star forming region. While Orion-KL/IRc2 is the main high-mass star formation region in Orion (with considerable star formation activity), we need to contrast this with a second high-mass star formation region with a more quiescent nature. A good example is found 1.5′ south of IRc2 in Orion-S. Orion-S has an infrared luminosity that is more than an order of magnitude below that of the KL cluster. In addition, a chemical study has suggested that this object may be in an earlier evolutionary stage than IRc2 (McMullin et al. 1993). A comparison between these sources will therefore be of great interest, since they presumably formed under similar conditions.

Beyond guaranteed time, Dr. Plume is also involved with another team of astronomers who propose to map the Entire Galaxy with the PACS and SPIRE instruments aboard Herschel. The unprecedented resolution and sensitivity afforded by Herschel will allow astronomers, for the first time, to obtain a complete census of cold dust clouds in the Galaxy. Studies of these objects will allow us to address how star forming molecular clouds are assembled and how the star formation process proceeds. In addition, it will help us find every massive star forming region in the Galaxy, placing studies of massive star formation onto a firm statistical basis.

Links

Herschel Science Centre: http://herschel.esac.esa.int/
ESA's Herschel Page: http://sci.esa.int/science-e/www/area/index.cfm?fareaid=16
Canadian HIFI Page: http://astro.uwaterloo.ca/HIFI/
Herschel Orion Survey: http://www.submm.caltech.edu/hexos/