Early images of the sky reflect progress in BETA commissioning

A 9-beam continuum image of the sky, created using the BETA test array of the ASKAP telescope. Credit: CSIRO

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

A radio image of galaxy NGC253, created using the 6-antenna ASKAP test array known as the Boolardy Engineering Test Array. Credit: 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."

One of the images, of a field containing a number of distant galaxies, covers 10 square degrees on the sky — 50 times larger than the full Moon — and was made from nine overlapping beams captured simultaneously, with a dynamic range of 50,000:1.

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 second image is of neutral atomic hydrogen gax (HI) from the NGC253 galaxy, capturing both the intensity of the radio waves and how the galaxy is rotating.

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.

For more information, read the CSIRO Media Release, or the latest edition of the ASKAP Update.

Back to Latest ASKAP News page.

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