Journal article

Discovery of H I gas in a young radio galaxy at z=0.44 using the Australian Square Kilometre Array Pathfinder

JR Allison, EM Sadler, VA Moss, MT Whiting, RW Hunstead, MB Pracy, SJ Curran, SM Croom, M Glowacki, R Morganti, SS Shabala, MA Zwaan, G Allen, SW Amy, P Axtens, L Ball, KW Bannister, S Barker, ME Bell, DC-J Bock Show all



We report the discovery of a new 21-cm HI absorption system using commissioning data from the Boolardy Engineering Test Array of the Australian Square Kilometre Array Pathfinder (ASKAP). Using the 711.5-1015.5 MHz band of ASKAP we were able to conduct a blind search for the 21-cm line in a continuous redshift range between z = 0.4 and 1.0, which has, until now, remained largely unexplored. The absorption line is detected at z = 0.44 towards the GHz-peaked spectrum radio source PKS B1740-517 and demonstrates ASKAP's excellent capability for performing a future wide-field survey for HI absorption at these redshifts. Optical spectroscopy and imaging using the Gemini-South telescope indicates th..

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University of Melbourne Researchers


Awarded by European Research Council under the European Union

Awarded by Australian Research Council Centre of Excellence for All-sky Astrophysics (CAASTRO)

Funding Acknowledgements

The Australian SKA Pathfinder is part of the Australia Telescope National Facility which is managed by CSIRO. Operation of ASKAP is funded by the Australian Government with support from the National Collaborative Research Infrastructure Strategy. Establishment of the Murchison Radio-astronomy Observatory was funded by the Australian Government and the Government of Western Australia. ASKAP uses advanced supercomputing resources at the Pawsey Supercomputing Centre. We acknowledge the Wajarri Yamatji people as the traditional owners of the Observatory site.JRA acknowledges support from a Bolton Fellowship. RM gratefully acknowledges support from the European Research Council under the European Union's Seventh Framework Programme (FP/2007-2013) ERC Advanced Grant RADIOLIFE-320745. Parts of this research were conducted by the Australian Research Council Centre of Excellence for All-sky Astrophysics (CAASTRO), through project number CE110001020. We have made use of ASTROPY, a community-developed core PYTHON package for astronomy (Astropy Collaboration, 2013); the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration; NASA's Astrophysics Data System Bibliographic Services; the SIMBAD data base and VizieR catalogue access tool, both operated at CDS, Strasbourg, France.The authors would also like to acknowledge the large group of people who have contributed to the planning, design, construction and support of BETA and ASKAP. This includes Kerry Ardern, Brett Armstrong, Jay Banyer, Samantha Barry, Tim Bateman, Ron Beresford, Brayden Briggs, Kate Brooks, Graeme Carrad, Ettore Carretti, Frank Ceccato, Raji Chekkala, Kate Chow, Geoff Cook, Paul Cooper, Evan Davis, Ludovico de Souza, Jack Dixon, Peter Duffy, Troy Elton, Brian Jeffs, Alex Harding, George Hobbs, Ron Koenig, Arkadi Kosmynin, Tom Lees, Amy Loke, Li Li, Stacy Mader, Tony Maher, Neil Marston, Vincent McIntyre, Ian McRobert, Samantha Mickle, Ray Moncay, Neale Morison, John Morris, Tony Mulry, Alan Ng, Wilfredo Pena, Nathan Pope, Brett Preisig, Lou Puls, Michael Reay, Ken Reeves, Adrian Rispler, Victor Rodrigues, Daniel Roxby, Tim Ruckley, Craig Russell, Aaron Sanders, Ken Smart, Mark Wieringa, Tim Wilson, Kjetil Wormnes and Xinyu Wu.