| 3rd of September 2015 |
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| ATLAS Third Data Release |
| by Thomas Franzen (ICRAR/UCurtin) |
| The Australia Telescope Large Area Survey
(ATLAS) is a deep 1.4 GHz radio continuum survey with ATCA. The third ATLAS
data release combines observations taken between 2002 and 2010 of an area
coincident with the Chandra Deep Field South (CDFS) and the European Large
Area ISO Survey South 1 (ELAIS-S1), two of the best-studied regions of the
sky at all wavelengths. The survey covers a total area of 6.3 deg2 to a
typical rms noise level of 15 microJy/beam. ATLAS is among the deepest and
widest radio surveys to date and is being used as a pilot survey for EMU,
the wide-field radio continuum survey planned for ASKAP which will cover the
whole Southern Sky to approximately the same depth as ATLAS, at a similar
resolution and frequency. Franzen et al. (2015) present the survey in detail, together with a catalogue containing 5118 component sources above 5 sigma. A second paper (Banfield et al. 2015, in preparation) will present the component counts and explore the distribution of spectral indices, and a third paper (Norris et al. 2015, in preparation) will group components into sources with optical/infrared identifications. Figure caption. Left: ATLAS DR1 image (Norris et al. 2006) of a 50 by 50 arcmin region of CDFS. Centre: ATLAS DR3 image of the same region of sky. The sensitivity in the DR3 image is about 2.5 times higher than in the DR1 image. Right: the most distant bent-tailed (BT) radio galaxy yet detected at a redshift of 2.1688 (Dehghan et al. 2014). In the distant Universe, BT radio galaxies are believed to be the signature of overdensities in large-scale structure. The DR1 and DR3 data are shown with blue and green contours, respectively; the greyscale is an infrared image from the SWIRE survey (Lonsdale et al. 2003). Note that the continuous tail is only visible in DR3 given the improved signal-to-noise ratio. |