GASS: The Parkes Galactic All-Sky Survey. I. Survey Description, Goals, and Initial Data Release

TL;DR

GASS is a highly sensitive, high-resolution survey of Galactic atomic hydrogen in the Southern sky, providing valuable data for astrophysical research.

Contribution

This paper introduces the GASS survey, detailing its goals, methodology, and initial data release, marking the most sensitive and highest resolution Galactic HI survey in the Southern sky.

Findings

First data release of GASS survey available online

Survey achieves ~16' angular resolution and 1.0 km/s velocity resolution

Provides a comprehensive, high-quality HI data set for the Southern sky

Abstract

The Parkes Galactic All-Sky Survey (GASS) is a survey of Galactic atomic hydrogen (HI) emission in the Southern sky covering declinations $\delta \leq 1^{\circ}$ using the Parkes Radio Telescope. The survey covers $2\pi$ steradians with an effective angular resolution of ~16', at a velocity resolution of 1.0 km/s, and with an rms brightness temperature noise of 57 mK. GASS is the most sensitive, highest angular resolution survey of Galactic HI emission ever made in the Southern sky. In this paper we outline the survey goals, describe the observations and data analysis, and present the first-stage data release. The data product is a single cube at full resolution, not corrected for stray radiation. Spectra from the survey and other data products are publicly available online.