WALLABY – an SKA Pathfinder H i survey

Bärbel S. Koribalski , L. Staveley-Smith , T. Westmeier , P. Serra , K. Spekkens , O.I. Wong , C.D.P. Lagos , D. Obreschkow , E.V. Ryan-Weber , M. Zwaan , V. Kilborn , G. Bekiaris , K. Bekki , F. Bigiel , A. Boselli (1) , A. Bosma (1) , B. Catinella , G. Chauhan , M.E. Cluver , M. Colless , H.M. Courtois (2) , R.A. Crain , W.J.G. de Blok , H. Dénes , A.R. Duffy , A. Elagali , C.J. Fluke , B.-Q. For , G. Heald , P.A. Henning , K.M. Hess , B.W. Holwerda , C. Howlett , T. Jarrett , D.H. Jones , M.G. Jones , G.I.G. Józsa , R. Jurek , E. Jutte , P. Kamphuis , I. Karachentsev , J. Kerp , D. Kleiner , R.C. Kraan-Korteweg , K. Lee-Waddell , A.R. López-Sánchez , J. Madrid , M. Meyer , J. Mould , C. Murugeshan , R.P. Norris , S.-H. Oh , T.A. Oosterloo , A. Popping , M. Putman , T.N. Reynolds , J. Rhee , A.S.G. Robotham , S. Ryder , A.C. Schröder , Li Shao , A.R.H. Stevens , E.N. Taylor , J.M. van Der Hulst , L. Verdes-Montenegro , B.P. Wakker , J. Wang , M. Whiting , B. Winkel , C. Wolf

1 LAM - Laboratoire d'Astrophysique de Marseille
2 IP2I Lyon - Institut de Physique des 2 Infinis de Lyon

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 \times12-m dishes equipped with Phased-Array Feeds (PAFs), located in an extremely radio-quiet zone in Western Australia. wallaby aims to survey three-quarters of the sky (-90^{\circ} < \delta< +30^{\circ}) to a redshift of z \lesssim0.26, 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 \sim0.05 (∼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).

Mots clés: Radio lines: galaxies; ISM – surveys – galaxies: evolution; formation; kinematics & dynamics; ISM – large-scale structure

Domaines: Astrophysique [astro-ph]; Instrumentations et Détecteurs [physics.ins-det]

Bärbel S. Koribalski, L. Staveley-Smith, T. Westmeier, P. Serra, K. Spekkens, et al.. WALLABY – an SKA Pathfinder H i survey. Astrophys.Space Sci., 2020, 365 (7), pp.118. ⟨10.1007/s10509-020-03831-4⟩. ⟨hal-02504669⟩