The spectacular sensitivity and resolution of observations which the largest optical-infrared telescopes are capable (cf. figure) can only be achieved by means of very sophisticated instruments behind these telescopes. Such instruments cannot be purchased "off-the-shelf", so they are generally developed by specialized instrumentation groups within the astronomical community. The NOVA Optical/IR Group hosted by ASTRON is one of the prominent groups in this field.
In the past 50 years our ‘window' on the universe has widened tremendously. With the powerful new observing tools of radiotelescopes and space instruments astronomers have now access to essentially all kinds of electromagnetic radiation, all the way from the ultra-short gamma rays to very long radio waves.
While astronomy has thus become a true multi-wavelength discipline, the optical-infrared wavelength range remains the ‘core region' of the spectrum, where most astronomical observations are made. Not only is this the wavelength region with the highest density of atomic and molecular lines, but it is also the region where the majority of stars, nebulae and galaxies emit most of their radiation. The optical-infrared spectrum is therefore particularly rich in astrophysical information.
Observations at optical and infrared wavelengths require cloudless skies and high atmospheric transparency. Such conditions are rare in The Netherlands. Dutch astronomers therefore rely on observations from remote mountaintops, such as ESO's Very Large Telescope in Chile and the UK-NL telescopes on La Palma (Canary Islands). For parts of the infrared spectrum, especially at the longer wavelengths, even the best ground-based observatories are not good enough and measurements from space become imperative.
Engineering state-of-the-art instrumentation is only possible when improved and novel techniques can be applied. The group has built up a reputation in achieving excellent solutions in opto-mechanical engineering, and inventing new solutions to meet the stringent requirements. Examples for this are the innovative cryogenic lens mounts for the Spiffi camera,
super light weighting of aluminum structures and polishing all aluminum mirrors to an excellent surface figure. This research is imperative to stay at the forefront of the instrumentation development in the world, despite the pressure to develop quickly at minimum risk real instruments.
The optical instrumentation group was originally founded in 1982 as a collaboration between the Kapteyn Institute (Groningen) and the Leiden Observatory, merging the technical groups of these two university institutes. Until 1996 the group was located at the Kapteyn Observatory in Roden, the small observatory of the Kapteyn Institute near Groningen.
With the advent of 8-10 meter class telescopes the scale and complexity of instrumentation projects increased significantly. It became clear that these new challenges could only be met by embedding the optical instrumentation work in a broader technological environment. The optical group therefore moved to Dwingeloo where it became part of ASTRON. In 2008, an agreement was signed by ASTRON and NOVA (the Dutch research school for Astronomy), and the NOVA Optical/IR group was formed. This group is now largely funded by NOVA with ASTRON as the host institute.
From the beginning the goal has been to develop instrumentation on world-class optical telescopes for the Dutch astronomical community. In particular this concerns the facilities of the European Southern Observatory in Chile and the Isaac Newton Group of telescopes on La Palma. In the course of 25 years a wide range of instruments has been built, but in general the emphasis has been on spectrographs, on the infrared wavelength range and consequently on cryogenic instruments.
Modern astronomical instruments are so complex and expensive that they can generally be built only by international teams with international funding. The NOVA optical/IR instrumentation group hosted by ASTRON has relations with many international partners such as Service d'Astrophysique (Saclay, France), Max Planck Institut für Astronomie (Heidelberg, Germany), Astronomy Technology Center (Edinburgh, UK) and the European Southern Observatory. Inside the Netherlands the group collaborates closely with the astronomical institutes at the universities, the space research institute SRON, the technical physics institute TNO and with the Dutch high-tech industry. NOVA, the Dutch research school for astronomy, has funded a large fraction of the recent instrumentation projects and plays an important role in defining the instrumentation strategy.
For more information please contact: Ramon Navarro: navarro [at] astron [dot] nl