Early images of the sky reflect progress in BETA commissioning
A 12-hour observation of an ASKAP test field
showing a number of distant galaxies, with the
Moon shown to scale. The circles indicate the
nine overlapping 'beams' from which the image
was created. Image: CSIRO.
ASKAP's ‘snapshot’ image of the galaxy
NGC 253, made over just 11 hours. The
colours show that the galaxy is rotating. The
‘hole’ in the centre is a region where radio
emission is absorbed. Image: CSIRO.
11 June 2014
New images of the sky show that CSIRO's ASKAP is functioning as an aperture-synthesis telescope after just a few months of commissioning.
"We've never had a telescope like this before," said CSIRO's Dr David McConnell, who leads the ASKAP Commissioning and Early Science team, ACES, "We can see that the novel aspects of its design really do work, and that it will outperform a conventional telescope."
The quality of the image vindicates ASKAP's two novel features:
The telescope's 'phased array feeds': new technology developed by CSIRO allows the telescope to see large areas of sky at once.
The antennas’ third axis of rotation: as the telescope tracks radio sources, the PAF is kept in a fixed orientation to the sky, eliminating artefacts from bright sources at the beam edges.
The phased array feeds (PAFs) used for these commissioning tests are the 'first generation', or Mk I, design. The first six ASKAP antennas equipped with the Mk I PAF receivers and all associated electronics at the Murchison Radio-astronomy Observatory is known as the Boolardy Engineering Test Array (BETA), a test array used to help the commissioning team prepare for the fit-out of the full ASKAP telescope.