Fibre multi-object spectrograph
Fibre optic spectrograph that is part of the Subaru Telescope in Hawaii
title: "Fibre multi-object spectrograph" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["telescope-instruments", "spectrographs", "electronic-test-equipment", "signal-processing", "laboratory-equipment"] description: "Fibre optic spectrograph that is part of the Subaru Telescope in Hawaii" topic_path: "engineering" source: "https://en.wikipedia.org/wiki/Fibre_multi-object_spectrograph" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0
::summary Fibre optic spectrograph that is part of the Subaru Telescope in Hawaii ::
::figure[src="https://upload.wikimedia.org/wikipedia/commons/7/7a/FMOS_Spectrograph2.gif" caption="FMOS – Fibre multi-object spectrograph"] ::
Fibre multi-object spectrograph (FMOS) is facility instrument for the Subaru Telescope on Mauna Kea in Hawaii. The instrument consists of a complex fibre-optic positioning system mounted at the prime focus of the telescope. Fibres are then fed to a pair of large spectrographs, each weighing nearly 3000 kg. The instrument will be used to look at the light from up to 400 stars or galaxies simultaneously over a field of view of 30 arcminutes (about the size of the full moon on the sky). The instrument will be used for a number of key programmes, including galaxy formation and evolution and dark energy via a measurement of the rate at which the universe is expanding.
Design, construction, operation
It is currently being built by a consortium of institutes led by Kyoto University and Oxford University with parts also being manufactured by the Rutherford Appleton Laboratory, Durham University and the Anglo-Australian Observatory. The instrument is scheduled for engineering first-light in late 2008.
OH-suppression
The spectrographs use a technique called OH-suppression to increase the sensitivity of the observations: The incoming light from the fibres is dispersed to a relatively high resolution and this spectrum forms an image on a pair of spherical mirrors which have been etched at the positions corresponding to the bright OH-lines. This spectrum is then re-imaged through a second diffraction grating to allow the full spectrum (without the OH lines) to be imaged onto a single infrared detector.
References
::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::