NIRES Data Format
NIRES raw spectra and images are stored as Multi-Extension FITS files (MEF). Each MEF consists of:
| HDU | Content |
|---|---|
| [0] | header and pixels |
| [1] | pixels |
| [2] | pixels |
Extension [0] stores the actual CDS or MCS data and the header. The header includes instrument specific keywords and general telescope keywords. Spectra are saved as 2048x1024 pixels arrays; images are 1024x1024 pixels. For a description of the keywords in the NIRES headers, visit http://www2.keck.hawaii.edu/koa/public/keywords/niresKeywords.php. Both spectral and image headers are populated with the World Coordinate System (WCS) information, providing access to approximate orientation, handedness, and astrometry in the image data; the sky coordinates presented on the spectra are meaningless since the raw data show the wavelength dispersion of light through a small slit.
Extensions [1] and [2] are reserved for a variance image and a data quality image that have not yet been implemented.
Please acknowledge the use of KOA by including this text in your publications:
This research has made use of the Keck Observatory Archive (KOA), which is operated by the W. M. Keck Observatory and the NASA Exoplanet Science Institute (NExScI), under contract with the National Aeronautics and Space Administration.
Please also acknowledge the PI(s) of datasets that have been obtained through KOA, and please contact the KOA Help Desk if you publish archival data.
If your research uses data reduced by the DEIMOS DRP or MOSFIRE DRP, please use the PypeIt Citation.
Privacy Policy Image Use Policy
The Keck Observatory Archive (KOA) is a collaboration between the NASA Exoplanet Science Institute (NExScI) and the W. M. Keck Observatory (WMKO). NExScI is sponsored by NASA's Exoplanet Exploration Program, and operated by the California Institute of Technology in coordination with the Jet Propulsion Laboratory (JPL).
