| 10th of September 2019 |
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| Countdown to ASKAP Survey Science |
| by Karen Lee-Waddell |
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To show ASKAP’s ability to image a complex field in three dimensions,
the WALLABY team
took spectral line observations of a region in the Eridanus
constellation. This target field is the intervening area between two
clusters of galaxies that are currently merging together. The new
ASKAP observations capture numerous galaxies in different
stages of evolution, enabling a more thorough understanding of this merging
process and its effects on the entire system.
The image above is a "cube" with one spectral and two spatial dimensions. This image cube was produced from about 10 hours of ASKAP observations, processed using ASKAPsoft, and shows only a small portion of ASKAP’s full field of view and spectral range. Each darker "blob" is a galaxy, detected using the 21-cm line emission of neutral hydrogen gas. There are seven neighbouring galaxies in this portion of space, one of which does not appear to have a stellar counterpart. The most noticeable galaxy in this group is NGC 1371, which has a ring-like distribution of hydrogen gas. The elongation of the galaxies in the third dimension indicates rotational motion as a portion of the gas is moving towards us, while another portion is moving away. More details of these observations, including a rotating version of the data cube, are available here. |