WALLABY - an SKA Pathfinder HI survey

Bärbel S. Koribalski*, L. Staveley-Smith, T. Westmeier, P. Serra, K. Spekkens, O. I. Wong, K. Lee-Waddell, C. D. P. Lagos, D. Obreschkow, E. V. Ryan-Weber, M. Zwaan, V. Kilborn, G. Bekiaris, K. Bekki, F. Bigiel, A. Boselli, A. Bosma, B. Catinella, G. Chauhan, M. E. CluverM. Colless, H. M. Courtois, 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. Jütte, P. Kamphuis, I. Karachentsev, J. Kerp, D. Kleiner, R. C. Kraan-Korteweg, Á. 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

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

The Widefield ASKAP L-band Legacy All-sky Blind surveY (WALLABY) is a next-generation survey of neutral hydrogen (HI) 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 radio-quiet 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 HI 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 HI 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).
Original languageEnglish
Article number118
JournalAstrophysics and Space Science
Volume365
DOIs
Publication statusPublished - 13-Jul-2020

Keywords

  • Radio lines: galaxies
  • ISM
  • surveys
  • galaxies: evolution
  • formation
  • kinematics &amp; dynamics
  • large-scale structure
  • Astrophysics - Astrophysics of Galaxies
  • Astrophysics - Cosmology and Nongalactic Astrophysics
  • Astrophysics - Instrumentation and Methods for Astrophysics

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