SANTA CRUZ DE TENERIFE, Oct. 31 (EUROPA PRESS) –
The William Herschel Telescope, located at the Roque de los Muchachos Observatory on the island of La Palma, has hosted the inauguration of the WEAVE instrument, a powerful state-of-the-art multimode and multifiber spectrograph that uses optical fibers to collect light from celestial sources and transmit it to a spectrograph.
The inauguration ceremony brought together the heads of the scientific funding agencies of the partner countries of the Isaac Newton Telescope Group (ING), as well as a large representation of the 500 members of the scientific teams and organizations involved in the design and construction of WEAVE, becoming the largest gathering of people ever held inside the dome of the William Herschel Telescope (WHT).
Rafael Rebolo, director of the Institute of Astrophysics of the Canary Islands (IAC), expressed in his speech that WEAVE “is a cutting-edge instrument with which the WHT telescope will have at least 10 years of excellent scientific production ahead of it.” “It is the result of a long and successful collaboration between the Science Councils of the United Kingdom, the Netherlands and the IAC that sought to make the WHT telescope a world reference in wide-field spectroscopic explorations.”
The director of the IAC trusts that this collaboration “will persist for a long time, continue to give excellent results and enhance the capabilities of our scientific communities and those of all the groups that have contributed to making this magnificent instrument a reality,” he concluded.
The WEAVE project was launched more than 10 years ago thanks to the push of a team of astronomers who believed in the potential of wide-field fiber spectroscopy to exploit large data sets, such as those provided by the Agency’s Gaia satellite. European Space Agency (ESA). In addition, they wanted to give the William Herschel Telescope a new role by opting for its renewal thanks to one of the largest astronomical lenses ever built.
After intense years of design and construction of its multiple elements in countries on four continents, WEAVE was finally installed at the WHT in May 2022 and obtained its first scientific data in December of that same year. During 2023, several of its observation modes have been fine-tuned and data has been obtained to verify its scientific capabilities.
The inauguration of WEAVE marks the beginning of its regular scientific exploitation and, more specifically, the start of the WEAVE Survey and open-time programs that use its large integral field unit (LIFU). Scientific programs using the multi-object spectroscopy (MOS) mode will begin in 2024, followed by observations with WEAVE’s third observation mode using small integral field units (mIFU).
WEAVE, the instrument
WEAVE is a multimode, multifiber spectrograph that uses optical fibers to collect light from celestial sources and transmit it to a spectrograph. WEAVE’s two-arm spectrograph separates light into its different wavelengths, or colors, and records them on large format CCD detectors. The raw data is transferred over the Internet to computers in Cambridge and Tenerife and the science-ready products are stored in an archive on La Palma for scientific exploitation.
The resulting spectra contain the fingerprints of the physical and chemical characteristics of stars, galaxies, quasars, and interstellar and intergalactic gas that astronomers use to test their theories about the Universe. They also allow astronomers to measure velocities along the line of sight using the Doppler effect.
One of WEAVE’s unique elements among multi-object spectrographs is its extraordinary sharpness in dividing incoming light into its wavelengths, also known as spectral resolving power, for up to 960 celestial sources simultaneously. While WEAVE’s spectral resolving power in low-resolution mode is comparable to that of other current multi-object spectrographs, its resolving power in high-resolution mode is five to ten times greater than that of other multi-object facilities in the Northern Hemisphere. This high resolving power translates into more accurate velocity measurements (as good as 1 km/s) and much more precise chemical abundance measurements than can be obtained with other Northern Hemisphere MOS facilities.
WEAVE’s versatility is another of its strengths. While LIFU mode houses 547 closely grouped fibers to image wide areas of the sky, in MOS mode two robots separately place up to 960 individual fibers to collect light from as many stars, galaxies and quasars. In mIFU mode, the fibers are organized into 20 units, each consisting of 37 fibers that are used to study small, extended targets such as nebulae and distant galaxies.
