The WHAM Sky Survey is available as two datasets. The first is a kinematic release containing more than 49,000 spectra covering the whole sky revealing Galactic Hα emission between roughly -100 to +100 km/s (LSR) with 12 km/s velocity resolution. The second dataset contains only the velocity-integrated (-80 to +80 km/s LSR) intensities of these pointings. As a convenience, the kinematic release contains the integrated dataset in separate fields.

You can browse a sample of the WHAM-SS through a set of pre-generated figures. These are suitable for use in presentations or posters with proper attribution.

Release Versions

Public releases are tagged with a major label (DR#), a survey version (YYMMDD), and a revision date (YYMMDD). The initial release is labeled DR1. Using these designations, the base name for public survey files follows: wham-ss-LABEL-vVERSION-RELEASE. For example, wham-ss-DR1-v161116-170111 is a file generated on 01/11/2017 from the DR1 survey base version 161116. See the documentation below for more details.


This document describes the WHAM-SS and the format of the data. Each data file also includes a README in the header or in an IDL variable. Please read them carefully before contacting us with questions.

Kinematic Survey (DR1-v161116-170316)

Integrated Survey (DR1-v161116-170316)

Release History

DR1-v161116-170111 : Initial public release.

DR1-v161116-170222 : Add integrated survey release in FITS image format. Tweak data file header documentation.

DR1-v161116-170317 : Add kinematic survey release in FITS cube format. No changes to other formats.

(The original northern-only survey release (NSS) is still available but is superseded by this release. It will no longer be updated and will be retired soon.)


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