The Evolutionary Map of the Universe Pilot Survey

TL;DR

The EMU Pilot Survey using ASKAP at 944 MHz mapped 270 square degrees, cataloging around 220,000 radio sources with high sensitivity and resolution, revealing new types of sources and exploring a previously uncharted parameter space.

Contribution

This paper presents the first data release and initial analysis of the EMU Pilot Survey, highlighting its high source density, sensitivity to low surface-brightness emission, and discovery of new source types.

Findings

Cataloged approximately 220,000 sources, including 180,000 single-component sources.

Detected new types of radio sources not seen in previous surveys.

Explored a new parameter space with high source density and sensitivity.

Abstract

We present the data and initial results from the first Pilot Survey of the Evolutionary Map of the Universe (EMU), observed at 944 MHz with the Australian Square Kilometre Array Pathfinder (ASKAP) telescope. The survey covers 270 \sqdeg of an area covered by the Dark Energy Survey, reaching a depth of 25--30 \ujybm\ rms at a spatial resolution of $\sim$ 11--18 arcsec, resulting in a catalogue of $\sim$ 220,000 sources, of which $\sim$ 180,000 are single-component sources. Here we present the catalogue of single-component sources, together with (where available) optical and infrared cross-identifications, classifications, and redshifts. This survey explores a new region of parameter space compared to previous surveys. Specifically, the EMU Pilot Survey has a high density of sources, and also a high sensitivity to low surface-brightness emission. These properties result in the detection of types of sources that were rarely seen in or absent from previous surveys. We present some of these new results here.