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NRAO/Socorro Colloquium Series

Ray Norris

ATNF/CSIRO

ASKAP-EMU: the challenge of deep wide radio continuum surveys


The Australian SKA Pathfinder (ASKAP) is now in the process of commissioning, and within the year we hope to start the EMU (Evolutionary Map of the Universe) survey. EMU will survey three quarters of the sky at 20cm to a sensitivity of 10 microJy, some 45 times deeper than NVSS, to yield a catalogue of 70 million galaxies, for many of which we will also measure spectral indices and polarization. EMU differs from previous wide radio surveys in reaching a sensitivity level at which star-forming galaxies, rather than AGN, dominate the source counts, and so the science is qualitatively different, reaching into diverse areas such as cosmology, galaxy evolution, and Galactic astronomy. However, the challenge of extracting the science from the data is formidable. For example, only about 1% of EMU sources will have a spectroscopic redshift, and so we are exploring new techniques for measuring the redshift distribution for an ensemble of radio sources. EMU also has the potential to discover unexpected new phenomena, as it is observing an unexplored part of the observational phase space. However, the petabytes of data, and consequent arms-length access to the data, may prevent an observer from recognizing such discoveries. Unexpected phenomena may lurk in dark corners of the database that will never be fully explored, and so remain undiscovered. Can we harness data-mining techniques to help the intelligent observer search for the unexpected in next generation surveys such as EMU? I believe we can, and indeed we must if we are to reap the full scientific benefit of next-generation telescopes.





May 24, 2013
11:00 am

Array Operations Center Auditorium

All NRAO employees are invited to attend via video, available in Charlottesville Auditorium, Green Bank Room 137 and Tucson N525.

Local Host: Minnie Mao

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