Science with ASKAP The Australian square-kilometre-array pathfinder
Johnston, S and Taylor, R and Bailes, M and Bartel, N and Baugh, C and Bietenholz, M and Blake, C and Braun, R and Brown, J and Chatterjee, S and Darling, J and Deller, A and Dodson, R and Edwards, P and Ekers, R and Ellingsen, SP and Feain, I and Gaensler, B and Haverkorn, M and Hobbs, G and Hopkins, A and Jackson, C and James, C and Joncas, G and Kaspi, V and Kilborn, V and Koribalski, B and Kothes, R and Landecker, T and Lenc, A and Lovell, JEJ and Macquart, JP and Manchester, R and Matthews, D and McClure-Griffiths, N and Norris, R and Pen, UL and Phillips, C and Power, C and Protheroe, R and Sadler, E and Schmidt, B and Stairs, I and Staveley-Smith, L and Stil, J and Tingay, S and Tzioumis, A and Walker, M and Wall, J and Wolleben, M, Science with ASKAP The Australian square-kilometre-array pathfinder, Experimental Astronomy, 22, (3) pp. 151-273. ISSN 0922-6435 (2008) [Refereed Article]
The future of cm and m-wave astronomy lies with the Square Kilometre
Array (SKA), a telescope under development by a consortium of 17
countries. The SKA will be 50 times more sensitive than any existing radio
facility. A majority of the key science for the SKA will be addressed through
large-area imaging of the Universe at frequencies from 300 MHz to a few GHz.
The Australian SKA Pathfinder (ASKAP) is aimed squarely in this frequency
range, and achieves instantaneous wide-area imaging through the development
and deployment of phase-array feed systems on parabolic reflectors. This
large field-of-view makes ASKAP an unprecedented synoptic telescope poised
to achieve substantial advances in SKA key science. The central core of ASKAP will be located at the Murchison Radio Observatory in inland Western
Australia, one of the most radio-quiet locations on the Earth and one of
the sites selected by the international community as a potential location for
the SKA. Following an introductory description of ASKAP, this document
contains 7 chapters describing specific science programmes for ASKAP. In
summary, the goals of these programmes are as follows:
- The detection of a million galaxies in atomic hydrogen emission across
75% of the sky out to a redshift of 0.2 to understand galaxy formation
and gas evolution in the nearby Universe.
- The detection of synchrotron radiation from 60 million galaxies to determine
the evolution, formation and population of galaxies across cosmic
time and enabling key cosmological tests.
- The detection of polarized radiation from over 500,000 galaxies, allowing a
grid of rotation measures at 10 to explore the evolution of magnetic fields
in galaxies over cosmic time.
- The understanding of the evolution of the interstellar medium of our own
Galaxy and the processes that drive its chemical and physical evolution.
- The high-resolution imaging of intense, energetic phenomena by enlarging
the Australian and global Very Long Baseline networks.
- The discovery and timing of a thousand new radio pulsars.
- The characterization of the radio transient sky through detection and monitoring of transient sources such as gamma ray bursts, radio supernovae
and intra-day variables.
The combination of location, technological innovation and scientific program
will ensure that ASKAP will be a world-leading radio astronomy facility,
closely aligned with the scientific and technical direction of the SKA. A brief
summary chapter emphasizes the point, and considers discovery space.