Telescope Instruments: DEIMOS

Instrument: Deep Extragalactic Imaging Multi-Object Spectrograph
Telescope: Keck II
Wavelength: visible light
Instrument Scientist: Dr. Carlos Alvarez
Description: Optical spectrograph that captures spectra of up to 130 galaxies or stars in a single exposure. In ‘Mega Mask” mode, its large field of view can take spectra of more than 1,200 objects simultaneously.
Unique Feature: DEIMOS relies on slitmasks – aluminum sheets with slits that match the coordinates of specific celestial objects. The slits are drilled into the custom-made sheets days before the scheduled nighttime observations, then installed in DEIMOS on the day of observing. At night, astronomers aim the telescope at the region of the sky where the slitmask precisely lines up with the objects they want to observe. This ability to take spectra from multiple objects in one single shot makes DEIMOS a powerful, efficient instrument. One can install up to 11 different slitmasks in a given night, making it a very versatile instrument.
Research Specialty: Studying the expansion of the universe and the chemical composition, structure, dynamics, and evolution of galaxies.
Notable Contributions: Played a key role in early investigations into the dark energy responsible for the accelerating expansion of the universe.

“The incredible sensitivity of DEIMOS has been critical in my research on the physical conditions and composition of the interstellar medium, which is the material that fills the space between stars. ~Dr. Carlos Alvarez