Instrument Modes:

As designed NIRI had two modes: (1) Imaging. Three plate scales are available. Altair is frequently combined with NIRI using the f/32 plate scale.  The data reduction should be basically the same for all three plate scales. (2) Spectroscopy (no longer offered)

Instrument design and use:

See the discussion on the Gemini NIRI web page Two reference articles on the design of the spectrograph are Hodapp et al. 1998, SPIE, 3354, 545 and Hodapp et al. 2000, SPIE, 4008, 1334.

Data reduction help:

Various pdf tutorials for both imaging and spectroscopy reductions are available on the Gemini IRAF getting-started page. This page links to pdf cookbooks that can be downloaded. Information is available here on the NIRI data characteristics and electronic pattern noise. A presentation by Knut Olsen and Andrew Stephens on reducing both imaging and long slit spectroscopy data was given at the 2010 Gemini Data Workshop. The Workshop documentation provides raw and reduced data that can be downloaded. A presentation is also available by Cecilia Farina that was given on NIRI data at the 2011 South American Gemini Data Workshop.

The NIRI instrument page also includes a section on data reduction. This contains subsections: on the following topics:

  • Data Primer – Discusses data format and the use of the Gemini NPREPARE.
  • CLEARIR – Discusses removing instrumental effects from NIRI and GNIRS data.
  • NIRLIN – This is a link to a python script to correct the detector non-linearity. The link goes to a beta version.
  • Warnings – A number of features of NIRI data are discussed here including the non-linearity problem.
  • Gemini IRAF – Links to the Gemini IRAF package

Data Reduction Manual

All of the above information and more has been combined into a manual. A draft is available here. More work needs to be done. We would appreciate hearing about software you find useful.

Last updated or reviewed August 9, 2017.

Updated on July 9, 2021, 10:55 am