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The Widefield ASKAP L-band Legacy All-sky Blind surveY (WALLABY) is a next-generation survey of neutral hydrogen (H I) in the Local Universe. It uses the widefield, high-resolution capability of the Australian Square Kilometer Array Pathfinder (ASKAP), a radio interferometer consisting of 36 × 12-m dishes equipped with Phased-Array Feeds (PAFs), located in an extremely radioquiet zone in Western Australia. WALLABY aims to survey three-quarters of the sky (−90 • < δ < +30 • ) to a redshift of z 0.26, and generate spectral line image cubes at ∼30 arcsec resolution and ∼1.6 mJy beam −1 per 4 km s −1 channel sensitivity. ASKAP's instantaneous field of view at 1.4 GHz, delivered by the PAF's 36 beams, is about 30 sq deg. At an integrated signal-to-noise ratio of five, WALLABY is expected to detect around half a million galaxies with a mean redshift of z ∼ 0.05 (∼200 Mpc). The scientific goals of WALLABY include: (a) a census of gas-rich galaxies in the vicinity of the Local Group; (b) a study of the H I properties of galaxies, groups and clusters, in particular the influence of the environment on galaxy evolution; and (c) the refinement of cosmological parameters using the spatial and redshift distribution of low-bias gas-rich galaxies. For context we provide an overview of recent and planned large-scale H I surveys. Combined with existing and new multi-wavelength sky surveys, WALLABY will enable an exciting new generation of panchromatic studies of the Local Universe. -First results from the WALLABY pilot survey are revealed, with initial data products publicly available in the CSIRO ASKAP Science Data Archive (CASDA).

We present MeerKAT observations of neutral hydrogen gas (H i) in the nearby merger remnant NGC 1316 (Fornax A), the brightest member of a galaxy group which is falling into the Fornax cluster. We find H i on a variety of scales, from the galaxy centre to its large-scale environment. For the first time we detect H i at large radii (70 -150 kpc in projection), mostly distributed on two long tails associated with the galaxy. Gas in the tails dominates the H i mass of NGC 1316: 7 × 10 8 M -14 times more than in previous observations. The total H i mass is comparable to the amount of neutral gas found inside the stellar body, mostly in molecular form. The H i tails are associated with faint optical tidal features thought to be the remnant of a galaxy merger occurred a few billion years ago. They demonstrate that the merger was gas-rich. During the merger, tidal forces pulled some gas and stars out to large radii, where we now detect them in the form of optical tails and, thanks to our new data, H i tails; while torques caused the remaining gas to flow towards the centre of the remnant, where it was converted into molecular gas and fuelled the starburst revealed by the galaxy's stellar populations. Several of the observed properties of NGC 1316 can be reproduced by a ∼ 10:1 merger between a dominant, gas-poor early-type galaxy and a smaller, gas-rich spiral occurred 1 -3 Gyr ago, likely followed by subsequent accretion of satellite galaxies.