Multi-Object Optical and Near-infrared Spectrograph (MOONS)

MOONS is a third-generation multi-object spectrograph (MOS) for the Very Large Telescope (VLT) of the European Southern Observatory (ESO) at the Paranal Obvservatory in Chile. It will use the full 251 diameter field of view of the VLT and deploy 1001 fibers. MOONS will go further into the infrared with three channels covering at once and at medium resolution (R„4000-7000), the [0.64-0.94 μm: RIZ], [0.94-1.35 μm: Y+J], and [1.45-1.81μm: H] bands  MOONS is one of the few highly multiplexed spectrographs planned for an 8m telescope.

MOONS will, for the first time, give high quality spectra for a statistically significant number (about a million) of galaxies at high redshift, matching a similar rest-frame wavelength, volume, range of environments and stellar masses as done by the Sloan Digital Sky Survey at z = 0. 

International consortium

MOONS is a European project led by the Science and Technology Facilities Council (STFC) at the UK Astronomy Technology Centre in Edinburgh. ETHZ, EPFL and UNIGE joined the MOONS Consortium in 2014 with a Memorandum of Understanding.

Probing galactic archaeology, galaxy evolution and cosmology

Very crucially, MOONS will unveil the 1.5 <= z <= 2.5 redshift range, at the peak of activity of star formation and galaxy assembly. This range is also known as the redshift desert because of the difficulty of spectroscopically identifying galaxies with optical facilities.

The field of view (fov) of MOONS (»10h -1Mpc) is ideal for the investigations of the large scale regions around galaxy clusters, the densest regions of the Universe, in which environmental effects are exacerbated. These studies are essential to our goals, which seek to trace the fate of galaxies from the cosmic filamentary structures and infalling groups onto the cluster cores.

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