RACS is the Rapid ASKAP Continuum Survey (RACS). It is the first large-area survey completed with the full 36-dish Australian SKA Pathfinder (ASKAP) telescope. ASKAP uses novel technology that allows it to achieve high survey speeds, making it one of the best instruments in the world for mapping the sky at radio wavelengths.
A revolution in survey science
RACS revolutionises the way we perform survey science because it allows astronomers to survey the entire sky in a matter of weeks rather than years, whilst still providing improved resolution and sensitivity compared to earlier surveys at similar wavelengths. There are a number of reasons why being rapid is exciting:
- It allows us to repeat the survey on a regular basis to see what has changed. The sky varies on different time-scales and objects can appear/disappear within seconds (Fast Radio Bursts), minutes (stellar flares), months (supernovae), or even years (Active Galactic Nuclei). Studying these requires regular and consistent observations but up until now we’ve only been able to study a handful of these at a time with traditional telescopes.
- It allows us to re-observe the sky in different frequency bands to better understand the physics of the objects we’re looking at.
- It allows follow-up observations for transient sources that are not well localised (gravitational wave detections or neutrino events).
- It provides more telescope time for other survey projects because it doesn’t monopolise the telescope for vast periods of time.