The consortium aims to propose the Wide Field Spectroscopic Telescope (WST) as a candidate project to become the next major observatory infrastructure of the European Southern Observatory (ESO) after the completion of the Extremely Large Telescope (ELT), currently under construction in the Chilean Andes.
The WST project aims to build a telescope entirely dedicated to wide-field spectroscopic surveys in the optical band, covering all types of celestial objects - from distant galaxies to asteroids and comets within our Solar System.
Professor Richard Ellis (UCL Physics & Astronomy) chaired a working group of international astronomers that first proposed the concept of the telescope in 2017.
He said: "The Wide Field Spectroscopic Telescope will produce cutting-edge, transformative science and will allow researchers to tackle key scientific questions in areas such as cosmology; the formation, evolution, and chemical enrichment of galaxies (including the Milky Way); the origin of stars and planets; astrophysics of transient or time-variable events; and multi-messenger astrophysics."
Professor Ellis will co-lead a large team of scientists defining the extragalactic component of the telescope’s scientific programme. Meanwhile, Professor Peter Doel (also UCL Physics & Astronomy) will investigate the technical aspects of designing the telescope.
Professor Doel said: "We are very excited to be involved in such an important
"The technical design of the Wide Field Spectroscopic telescope will involve the implementation of recent advancements in cutting-edge technologies that promise to produce a facility with revolutionary capabilities."
The consortium includes 19 research institutions across Europe and Australia, with a science team of over 600 members from 32 countries. The project is led by Professor Roland Bacon of Centre National de la Recherche Scientifique (CNRS, France) and Dr Sofia Randich of Istituto Nazionale di Astrofisica (INAF, Italy).
WST, the consortium says, promises to fulfil a critical need identified by the international scientific community: a telescope with a 12-metre primary mirror exclusively dedicated to the spectroscopic observations of celestial sources.
The demand for such an observational infrastructure is stated in numerous strategic international scientific plans outlining the key priorities for astrophysical research in the coming decade, including the European Astronet Roadmap 2023.
Despite ongoing construction of ground-based telescopes with 30-40-metre mirrors, there are no existing or planned facilities with WST’s unique characteristics. These include a 12-metre main mirror, a multi-object spectrograph (MOS) which can observe many objects at once over a large area of the sky (approximately the area of 12 full moons), and a panoramic integral field spectrograph (IFS) that captures a smaller area of the sky, about nine square arc minutes, but with detailed, high-quality data.
Professor Bacon said: "These specifications are highly ambitious and position the WST In just five years, the MOS would acquire spectra from 250 million galaxies and 25 million stars at low spectral resolution, plus over two million stars at high resolution, while the IFS would provide four billion spectra, enabling researchers to fully characterize these sources.
"To put these figures into perspective, it would take 43 years to obtain the same four billion spectra using the IFS available on ESO’s Very Large Telescope or 375 years using the upcoming 4MOST instrument to observe 250 million galaxies at the same depth."
Mark Greaves
m.greaves [at] ucl.ac.uk+44 (0)20 3108 9485
- University College London, Gower Street, London, WC1E 6BT (0) 20 7679 2000
