UCLA Infrared Lab



OH-Suppressing Infra-Red Imaging Spectrograph

PI: James Larkin (UCLA)
Project Scientist: Andreas Quirrenbach (UCSD)
Co-PI: Alfred Krabbe (UC Berkeley)

NOTE: The Keck OSIRIS Toolbox now has latest version of the OSIRIS pipeline.


OSIRIS is an integral field spectrograph designed to work with the Keck Adaptive Optics System. It uses an array of tiny lenses to sample a rectangular patch of the focal plane and produces spectra at up to 3000 locations simultaneously. There is also an internal diffraction limited camera with a 20x20 arcsec field of view. Both the camera and spectrograph can operate at wavelengths between 1 and 2.4 microns. The center of the imaging camera’s field is about 20 arcsec offset from the center of the spectrograph field and both can be used simultaneously with the same or different filters.

The spectrograph has plate scales of 0.02, 0.035, 0.05 and 0.10 arcsec per lenslet. The spectral resolution averages 3800 in the three finest plate scales, but is closer to 3400 in the 0.100 arcsec plate scale. In the broadband mode each spectrum contains a full broad band (z, J, H or K) and a total of 16x64 (actually 1019) spectra are taken. In the narrowband mode, a typical spectrum contains 1/4th of a broad band and an individual exposure contains between 16x64 to 48x64 spectra depending on the exact filter selected. The imager has a single fixed plate scale of 0.020 arcsec per pixel.

A great deal of thought has gone into trying to make OSIRIS easy to use. For the spectrograph, the only user selectable items are the plate scale, the filter, and the exposure time. The imager only has a filter and an exposure time setting. A great deal of complexity, however, is allowed in the observing sequences and the slaving of the imager to the spectrograph. All setup and control aspects of the instrument are managed by a few GUIs.

There is also a data reduction system that includes a “real-time” reduction of raw frames into cubes for display and basic analysis. In this real-time mode, it takes about one minute for a preliminary data cube to appear in the “quicklook” display package. The reduction system also includes a growing set of final reduction steps including correction of telluric absorption and mosaicing of multiple cubes.

First light was obtained on February 22, 2005 - See OSIRIS 1st Light Pictures!

The OSIRIS Toolbox

NOTE: Keck has become the primary distributor of the OSIRIS Data Reduction Pipeline. Some of the following information and files have been redirected to Keck! Please access the new OSIRIS Toolbox at this link: http://www2.keck.hawaii.edu/inst/osiris/tools/

The OSIRIS team and Keck staff would like to help OSIRIS users achieve a successful and rewarding observing experience! OSIRIS is an innovative and unique spectrograph, and hence it takes more preparation than traditional spectrographs with planning and reductions. We suggest looking over the OSIRIS manual prior to your observing run as well as the Keck OSIRIS webpage for further telescope and AO information. We have included links to the packages you will need for pre-observing (manual and planning GUI) and post-observing (Quicklook2 and data reduction pipeline).

OSIRIS User's Manual (pdf) - (v4.2 05/07/2018) Please refer to the OSIRIS manual for a complete description of OSIRIS capabilities, observational procedures, data reduction system, detector performance, filter curves, and much more.

OSIRIS Software Github - The OSIRIS software is now hosted on github. Historical descriptions are listed below.

Observing Planning GUI - OSIRIS observers can generate and save planning scripts, data definition files (.ddf), for observing with the spectrograph and imager by using the Observing Planning GUI. This java package will be identical to what you will be using at the telescope and requires java 1.4 or higher. To use, download and unpack the package and refer to the README file.

Quicklook2 Package - OSIRIS spectrograph frames are 3D FITS files that require sophisticated image visualization tools. The OSIRIS team presents an IDL based software package called Quicklook to display and analyze your OSIRIS data cubes. Quicklook is the OSIRIS image analysis software used at Keck while observing, but we also encourage using Quicklook for post-observing analysis of 2-D and 3-D fits frames. To use, simply download the tar file and unpack the file somewhere in your IDL path. Edit the environment variable 'QL_FILEDIR' in the file 'run_ql2' to match the directory path where you just unpacked Quicklook2.tar file. Once this environment variable has the correct path, you are ready to start using Quicklook2. Type 'run_ql2' at your terminal prompt within the same directory, and this script should launch Quicklook2 program and place the IDL xterm in an icon. In Windows, type 'run_wql2' at the IDL prompt. This software package supports the UNIX, LINUX, Mac OS, and Windows operating systems and operates on IDL versions 5.4 or higher.

Quicklook2 User's Manual (pdf) (v2.2 - 04/01/2008) - For a complete description of Quicklook functionality and operation procedures, please see the Quicklook Users Manual. This manual also has detailed instructions on installing Quicklook onto local machines.

Data Reduction Pipeline - Due to the unique nature of OSIRIS data and of its calibration steps, the OSIRIS team has developed a comprehensive pipeline designed to fully reduce all of the calibration data and to reduce scientific data to the level where an astronomer can begin custom analysis. The OSIRIS pipeline is designed to fix artifacts on the raw 2D array, wavelength calibrate, and assemble all the spectra into a 3D cube (λ wavelength, x and y spatially). In addition, after the 3D cube is assembled the pipeline allows for mosaicking of multiple frames with integer lenslet steps. The OSIRIS team is continually optimizing the pipeline and analysis tools for all users. However, unlike space-based data reduction pipelines, the general user is responsible for generating their own custom analysis tools for their specific scientific project. The OSIRIS team and other users have been developing stand alone analysis tools. We highly recommend and support a cohesive community for OSIRIS data reductions and analysis. Please see the OSIRIS manual for detailed instructions on how to install and run the data reduction pipeline.

Data Reduction GUI - The pipeline accepts commands only from XML (eXtensible Markup Language) files that we refer to as data reduction files (DRFs). Users may either hand edit these DRFs or use the java ODRFGUI package which generates DRFs with the user specifications. This GUI allows users to easily select pipeline modules, input directories, output directories, and execute scripts into the pipeline. This GUI should only be used with the version 2.0 or higher of the pipeline, and requires java 1.4 or higher. To use, download and unpack the package and consult the README file.

OSIRIS Updates - This website lists all the major hardware and software changes, and information on the calibration scans for OSIRIS. The pipeline uses a calibration scan for each independent mode (combination of filter and scale) to determine the spectral extraction and wavelength solution. Please use this page to determine which calibration scans you should be using for your observations.


The OSIRIS team would prefer the following reference to be cited when referring to the instrument in publication:
"OSIRIS: a diffraction limited integral field spectrograph for Keck"
Larkin et al. 2006, Proceedings of the SPIE, Volume 6269, pp. 62691A (2006)

OSIRIS Engineering Team: James Larkin, Matthew Barczys, Alfred Krabbe, Sean Adkins, Ted Aliado, Paola Amico, George Brims, Randy Campbell, John Canfield, Thomas Gasaway, Allan Honey, Christof Iserlohe, Chris Johnson, Evan Kress, David Lafreniere, Ken Magnone, Nick Magnone, Michael McElwain, Juleen Moon, Andreas Quirrenbach, Gunnar Skulason, Inseok Song, Michael Spencer, Jason Weiss, and Shelley Wright

OSIRIS Commissioning Team: James Larkin, Matthew Barczys, Alfred Krabbe, Christof Iserlohe, Michael McElwain, Andreas Quierrenbach, Jason Weiss, and Shelley Wright

OSIRIS Keck Support Team: Jim Lyke, Randy Campbell, and Al Conrad

OSIRIS Data Reduction Pipeline Team: James Larkin, Shelley Wright, Jason Weiss, Mike McElwain, Marshall Perrin, Christof Iserlohe, Alfred Krabbe, Tom Gasaway, and Tommer Wizanski

OSIRIS Quicklook2 Package: Michael McElwain, Jason Weiss, Marshall Perrin, and James Larkin

OSIRIS Science Publications

(25 papers and running...)

"Diffraction-limited Imaging Spectroscopy of the Sagittarius A* Region Using OSIRIS, a New Keck Instrument"
Krabbe et al. 2006, ApJL, Volume 642, Issue 2, pp. L145-L148

"First High-Contrast Science with an Integral Field Spectrograph: The Substellar Companion to GQ Lupi"
McElwain et al. 2007, ApJ, Volume 656, Issue 1, pp. 505-514

"Integral Field Spectroscopy of a Candidate Disk Galaxy at z ~ 1.5 Using Laser Guide Star Adaptive Optics"
Wright et al. 2007, ApJ, Volume 658, Issue 1, pp. 78-84

"Laser Guide Star Adaptive Optics Integral Field Spectroscopy of a Tightly Collimated Bipolar Jet from the Herbig Ae Star LkHα 233"
Perrin & Graham 2007, ApJ, 670, 499

"Tvashtar awakening detected in April 2006 with OSIRIS at the W.M. Keck Observatory"
Laver, de Pater, & Marchis 2007, Icarus, 191, 749

"Widespread Morning Drizzle on Titan"
Ádámkovics et al. 2007, Science, 318, 5852, 962

"Integral Field Spectroscopy of High-Redshift Star Forming Galaxies with Laser Guided Adaptive Optics: Evidence for Dispersion-Dominated Kinematics"
Law et al. 2007, ApJ, 669, 929

"High-contrast imaging with Keck adaptive optics and OSIRIS"
McElwain et al. 2008, SPIE, 7015

"A Near-Infrared Variability Study of the Galactic Black Hole: A Red Noise Source with NO Detected Periodicity"
Do et al. 2009, ApJ, 691, 1021

"The Role of Molecular Gas in Obscuring Seyfert Active Galactic Nuclei"
Hicks et al. 2009, ApJ, 696, 448

"The Kiloparsec-Scale Kinematics of High-Redshift Star-Forming Galaxies"
Law et al. 2009, ApJ, 697, 2057

"Dynamics of Galactic Disks and Mergers at z~1.6: Spatially Resolved Spectroscopy with Keck Laser Guide Star Adaptive Optics"
Wright et al. 2009, ApJ, 699, 421

"An OSIRIS Study of the Gas Kinematics in a Sample of UV-Selected Galaxies: Evidence of "Hot and Bothered" Starbursts in the Local Universe"
Basu-Zych et al. 2009, ApJL, 699, L118

"The global distribution of sulfur dioxide ice on Io, observed with OSIRIS on the W.M. Keck telescope"
Laver & de Pater 2009, Icarus, 201, 72

"Component-resolved Near-infrared Spectra of the (22) Kalliope System"
Laver et al. 2009, Icarus, 204, 574

"Probing young massive clusters with laser guide star adaptive optics"
McCrady, N. 2009, ApSS, 324,109

"Evidence for strong dynamical evolution in disc galaxies through the last 11 Gyr. GHASP VIII - a local reference sample of rotating disc galaxies for high-redshift studies"
Epinat et al. 2010, MNRAS, 401, 2113

"The Presence of Weak Active Galactic Nuclei in High Redshift Star Forming Galaxies"
Wright et al. 2010, ApJ, 711, 1291

"Resolved spectroscopy of gravitationally lensed galaxies: recovering coherent velocity fields in subluminous z ~ 2-3 galaxies"
Jones et al. 2010, MNRAS, 369

"Discovery of a Young L Dwarf Binary, SDSS J224953.47+004404.6AB"
Allers et al. 2010, ApJ, 715, 561 (using OSIRIS Imager)

"The Lick AGN Monitoring Project: The MBH - sigma Relation For Reverberation-Mapped Active Galaxies"
Woo et al. 2010, ApJ, 716, 269

"The 2008 Outburst in the Young Stellar System Z CMa: The First Detection of Twin Jets"
Whelan et al. 2010, ApJ, 720L, 119W

"Near-infrared Spectroscopy of the Extrasolar Planet HR 8799 b"
Bowler et al. 2010, ApJ, 723, 850

"The Black Hole Mass in Brightest Cluster Galaxy NGC 6086"
McConnell et al. 2010, arxiv:1009.0750 U

"Measurement of a Metallicity Gradient in a z=2 Galaxy: Implications for Inside-Out Assembly Histories"
Jones, Ellis, Jullo, & Richard 2010, arxiv:1010.1538

"Clouds and Chemistry in the Atmosphere of Extrasolar Planet HR8799b"
Barman, Macintosh, Konopacky, Marois 2011, arxiv:1103.3895

"The Nature of Double-peaked [O III] Active Galactic Nuclei"
Fu, Hai; Yan, Lin; Myers, Adam D.; Stockton, Alan; Djorgovski, S. G.; Aldering, G.; Rich, Jeffrey A, ApJ, 745, 67F

If your OSIRIS paper is not represented here, please contact the with your paper details.

OSIRIS Team Page (password reaquired)