GASS: THE PARKES GALACTIC ALL-SKY SURVEY. I. SURVEY DESCRIPTION, GOALS, AND INITIAL DATA RELEASE

Abstract

The Parkes Galactic All-Sky Survey (GASS) is a survey of Galactic atomic\nhydrogen (HI) emission in the Southern sky covering declinations $\\delta \\leq\n1^{\\circ}$ using the Parkes Radio Telescope. The survey covers $2\\pi$\nsteradians with an effective angular resolution of ~16', at a velocity\nresolution of 1.0 km/s, and with an rms brightness temperature noise of 57 mK.\nGASS is the most sensitive, highest angular resolution survey of Galactic HI\nemission ever made in the Southern sky. In this paper we outline the survey\ngoals, describe the observations and data analysis, and present the first-stage\ndata release. The data product is a single cube at full resolution, not\ncorrected for stray radiation. Spectra from the survey and other data products\nare publicly available online.\n