INGIsaac Newton Group of Telescopes

Contact details:

Prof. dr. S.C. Trager
Postbus 800, 9700 AV Groningen

The Isaac Newton Group of Telescopes (ING) consists of the 4.2-m William Herschel Telescope (WHT) and the 2.5-m Isaac Newton Telescope (INT), operating on the island of La Palma in the Canary Islands, Spain. The telescopes provide the way for Dutch astronomers to take observations of objects in the Northern sky, to generate surveys of parts of the sky to help understanding the nature of stars and galaxies, and they way they formed, and to obtain more detailed information about objects that for some reason are expected to be important for new scientific insight and discoveries. An example is a radio source, discovered with the LOFAR radio telescope, for which an optical spectrum is obtained on the WHT to find out whether it is a distant galaxy or to measure its distance. The facility has been running since May 1984, when the INT began scheduled use by the astronomical community. In August 1987 the WHT followed. The ING is located at the Observatorio del Roque de los Muchachos, one of the best astronomical sites in the world. Its core mission includes the execution of top-quality research with the best telescopes of their class in the world.

The ING provides astronomers in the Netherlands with access to the Northern Hemisphere sky in the optical and infrared, providing a unique opportunity to combine their radio observations obtained with LOFAR and and WSRT, to study the Milky Way’s outer disk and halo and the Northern extragalactic sky.
The WHT will soon (2017) be equipped with the WEAVE spectrographic survey facility. WEAVE is comprised of a new 2º field-of-view prime focus corrector with a 1000-multiplex fibre positioner, 20 small individually-deployable integral field units (IFUs), and a large IFU, each of which can feed a dual-beam spectrograph that provides full coverage of the visible spectra at a resolution of 5000 or two narrower wavelength ranges at resolution 20000. The instrument is designed specifically to provide spectra of any of the nearly 1 billion stars that ESA’s astrometric satellite Gaia won’t be able to measure itself and to provide dedicated follow-up of LOFAR and WSRT/APERTIF surveys. WEAVE will help Gaia to revolutionise our understanding of the formation and evolution of our own Milky Way and LOFAR and APERTIF to deepen our understanding of the evolution of gas out to times when the Universe was only a few billion years old and to find sources that will directly probe the Epoch of Reionisation. WEAVE will also study the early and last phases of stellar evolution, the evolution of the stellar populations of galaxies out to a time when the Universe was only half its current age, and provide probes of the structure of the Universe through the masses of clusters of galaxies and the evolution of the clustering of gas through its impact on sight lines to distant massive black holes (quasars).
WEAVE will be the dominant instrument on the WHT for the period 2017-2027, to be used more than 70% of the total nights available on the telescope. The remaining time will be used by other instruments, including visiting instruments, the single-slit dual-beam spectrograph ISIS, the imaging spectrograph ACAM, and the near-infrared imaging spectrograph LIRIS. These instruments allow for a wide range of astronomical investigations, from single stars to distant galaxies and from characterization of exoplanet atmospheres to studying the most extreme explosions in the Universe.
The INT is currently equipped with an 0,5º-diameter optical wide-field imaging camera (WFC) and a long-slit, single-object optical spectrograph (IDS). The WFC has been used to study faint solar system objects in the Kuiper Belt, the evolution of stars in the disk of our Milky Way, the faintest regions of our neighbor galaxy Andromeda, and clusters of galaxies. The IDS has been used to study exoplanet atmospheres, to provide the largest and best collection of stellar spectra for studies of distant galaxies, and to hunt for the most pristine stars in the Milky Way. A discussion is underway on the future of the INT; a likely outcome is that a new high-resolution, high-stability spectrograph to hunt for exoplanets will be installed in the coming years and may be the dominant instrument on the INT in the years 2019-2027.