WALLABY – an SKA Pathfinder H i survey

• Published in: Astrophysics and space science Vol. 365; no. 7
• Main Authors: Koribalski, Bärbel S., Staveley-Smith, L., Westmeier, T., Serra, P., Spekkens, K., Wong, O. I., Lee-Waddell, K., Lagos, C. D. P., Obreschkow, D., Ryan-Weber, E. V., Zwaan, M., Kilborn, V., Bekiaris, G., Bekki, K., Bigiel, F., Boselli, A., Bosma, A., Catinella, B., Chauhan, G., Cluver, M. E., Colless, M., Courtois, H. M., Crain, R. A., de Blok, W. J. G., Dénes, H., Duffy, A. R., Elagali, A., Fluke, C. J., For, B.-Q., Heald, G., Henning, P. A., Hess, K. M., Holwerda, B. W., Howlett, C., Jarrett, T., Jones, D. H., Jones, M. G., Józsa, G. I. G., Jurek, R., Jütte, E., Kamphuis, P., Karachentsev, I., Kerp, J., Kleiner, D., Kraan-Korteweg, R. C., López-Sánchez, Á. R., Madrid, J., Meyer, M., Mould, J., Murugeshan, C., Norris, R. P., Oh, S.-H., Oosterloo, T. A., Popping, A., Putman, M., Reynolds, T. N., Rhee, J., Robotham, A. S. G., Ryder, S., Schröder, A. C., Shao, Li, Stevens, A. R. H., Taylor, E. N., van der Hulst, J. M., Verdes-Montenegro, L., Wakker, B. P., Wang, J., Whiting, M., Winkel, B., Wolf, C.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.07.2020; Springer Nature B.V
• Subjects: Arrays; Astrobiology; Astronomy; Astrophysics; Astrophysics and Astroparticles; Cosmology; Cubes; Field of view; Galactic clusters; Galactic evolution; Galaxies; Galaxy distribution; Hydrogen; Line spectra; Local group (astronomy); Observations and Techniques; Original Article; Physics; Physics and Astronomy; Polls & surveys; Radio interferometers; Red shift; Signal to noise ratio; Sky surveys (astronomy); Space Exploration and Astronautics; Space Sciences (including Extraterrestrial Physics; Universe; ISM – large-scale structure; ISM – surveys – galaxies: evolution, formation, kinematics & dynamics; Radio lines: galaxies
• ISSN: 0004-640X; 1572-946X
• DOI: 10.1007/s10509-020-03831-4

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 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 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).