In June 2009, WMKO and UCO/Lick commissionined a new red-side dewar for LRIS featuring a new detector mosaic. Please review LRIS Red Upgrade Observing Notes for discriptions of the changes to LRIS software, detector characteristics, and on-sky performance measurements.

Pre-Observing Observing Post-Observing
Follow this link for information about pre-observing activities: proposal preparation, mask design and submission, pre-run activities, etc. Follow this link for information about your observing run: instrument and telescope setups, scripts, software, procedures, etc. Follow this link for information about your post-observing activities: backups, comment forms, data reduction, etc.
Trouble Shooting Technical Pages Index
Trouble Shooting pages and links. Portal to the LRIS technical pages: for the initiated only! A listing of the instrument pages.

ADC Released for 2007B.

For a description of the ADC please see: ADC Docs.

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The Low Resolution Imaging Spectrometer (LRIS) is a visible-wavelength imaging and spectroscopy instrument commissioned in 1993 and operating at the Cassegrain focus of Keck I.

LRIS was built at Caltech under the supervision of Bev Oke and Judy Cohen. Later James McCarthy and Chuck Steidel took responsibility for adding the blue side.

Reference paper: "The Keck Low Resolution Imaging Spectrometer", Oke, J.B., et al.. 1995, PASP, 107, 375

Beamsplitters separate the light between two arms. The red and blue cameras may be operated simultaneously, and together they may acquire spectra covering a 3200-10,000 Angstroms wavelength range.

The field of view in both modes of operation is 6×7.8 arcmin. The red camera uses a backside-illuminated Tek 2048×2048 CCD detector with a pixel scale of 0.211 "/pixel. The blue camera has a mosaic of 2 2Kx4K Marconi CCDs and the pixel scale is 0.135 "/pixel. The standard imaging filters include the UBVGRI passbands plus a small number of narrowband imaging filters.

Spectroscopy can be performed using a standard complement of longslits of various widths, or in multi-object mode, by using designed slitmasks which are milled on-site. An assortment of gratings (red side) and grisms (blue side) yield resolutions ranging from R=300-5,000, with peak system efficiencies of ~50%.

An optional polarimeter module enables spectropolarimetry.

Instrument master is Marc Kassis. See the instrument master home page.