Parkes Galactic All Sky Survey (GASS)

This map corresponds to the 21-cm emission from Galactic neutral Hydrogen for the entire sky south of δ = +1° using the thirteen beam 20 cm multibeam receiver on the Parkes Radio Telescope. GASS covers all Milky Way velocities between LSR -400 km/s and 500 km/s. The resolution of the map is 16' and the units are cm-2.

Healpix maps made by D. Paradis.


'GASS: The Parkes Galactic All-Sky Survey. Update: improved correction for instrumental effects and new data release, Kalberla and Haud, 2015, A&A, 578, 78

'Gass: The Parkes Galactic All-Sky Survey. I. Survey Description, Goals, and Initial Data Release' by McClure-Griffiths et al, 2009, ApJS, 181, 398

Map (in cm-2) (3rd release)


Uncertainty Map (in Jy)


Enter the following URL in Aladin (“Files” then “Use directly a URL”):

Original WCS Data

Project Website