Gemini Web Information Overview

Information about how to handle your Gemini data can be found at Gemini Phase III website. This page includes Gemini web page links that discuss all the data processing steps from quallity assessment through publication and observer feedback. Some of the most useful links are:

Getting your data

All data must be retrieved from the Gemini Observatory Archive (GOA). Additional information on the GOA can be found here.

Gemini data format

Data from Gemini facility instruments is in Multi-Extension FITS (MEF) format. MEF files consist of a Primary Header Unit (PHU) and one or more extensions that contain pixel data. The PHU is indexed 0, the first extension is indexed 1, etc. Standard IRAF is designed to work with FITS files that contain header and pixel data in a single file. Gemini IRAF/Pyraf and DRAGONS routines were written to work with MEF files. Additional details can be found on the Gemini website under data-formats.

Gemini IRAF

  • Option 1 (Geminiconda): The Gemini IRAF package and its dependencies, including IRAF and PyRAF, are distributed as a Legacy Software Stack of AstroConda, which is a free Conda channel maintained by the STScI. Download and other information on these packages can be found at the Gemini Data Reduction Software webpage.
  • Option 2 (Gemini Virtual Machine): For users of MacOS 10.15+, which no longer supports running the necessary 32-bit IRAF binaries natively. The virtual machine image has all the necessary packages (Anaconda, AstroConda, Gemini IRAF, and DRAGONS) pre-installed. Further details and instructions can be found at
  • Getting started with IRAF:


Gemini's new Python-based data reduction platform, DRAGONS (Data Reduction for Astronomy from Gemini Observatory North and South) is currently capable of reducing any imaging data from current instruments. Its use is recommended whenever possible, and new modes and instruments are being added. More information can be found at the Gemini Data Reduction Software webpage.

Gemini Instruments

The Gemini website provides links on data reduction for each instrument. Also, the General information on near-IR observations page includes wavelength calibration information, line lists, photometric, spectroscopic, telluric standard lists, spectral templates, etc. There is additional data reduction information for each Gemini instrument on the instrument's web page under the topic “data format and reduction”.

Workshops, examples, data reduction forum

Still needs help?

You can access the Gemini Helpdesk for all types of help, and also reach out to the US NGO members.


Updated on June 30, 2021, 7:29 am