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The
ASKAP Commissioning Update for June describes the public release
of data from the first science test field observed with the full ASKAP
array. The Galaxy And Mass Assembly (GAMA) fields were originally
selected to contain a rich number of extra-galactic sources and have
already been observed in several wavelength bands. The first
multi-beam observation with the full ASKAP array was of the GAMA23
field in continuum mode with frequency resolution averaged to 1 MHz at
the time of data capture. Most of the GAMA23 field fits neatly within
two side-by-side ASKAP footprints. These two tiles were observed with
the square 6x6 beam footprint over two consecutive nights, for 9 and
10 hours. The observations used a centre frequency of 888 MHz with 288
MHz of bandwidth. Since these were the first wide-field observations
with the full array, it took roughly three months to refine the
imaging parameters through iterative processing. The resulting images
have a typical noise background of 37 microJy RMS, which is very close
to the expected thermal noise. With the spatial resolution of the full
array we now have 215 million pixels over both tiles, making the image
difficult to display all at once! The image above shows a close-up of
the second tile, showing a giant radio galaxy in the bottom-right and
many others scattered throughout the field.
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