Our ASKAP radio telescope is out of this world at finding new features of our Universe. Through ASKAP’s survey science projects, nine teams will be using its stellar capabilities to learn even more about the Universe.
ASKAP is close to launching into full observational capacity. So let’s meet the projects and secrets of the Universe they’re aiming to reveal.
The Wajarri Yamaji are the Traditional Owners and native title holders of the Inyarrimanha Ilgari Bundara, our Murchison Radio-astronomy Observatory, which also hosts ASKAP. These survey science projects have been beautifully illustrated by Wajarri Yamaji artists.
CRAFT (Commensal Real-time ASKAP Fast Transients)
Fast radio bursts are one of the newest mysteries in astronomy. Despite their newness, they’ve already been useful in uncovering the Universe’s ‘missing matter’. CRAFT surveys all the data coming in from ASKAP to find these fast radio bursts. It also searches for other fast transients, which are radio signals that last for less than five seconds.
Radio signals like this come from matter that is under extreme conditions not possible to achieve on Earth. Such signals gives us an interesting insight into how matter behaves. CRAFT also enables the study of objects with a high brightness temperature, the effects of strong gravitational fields and the characteristics of intergalactic medium.
DINGO (Deep Investigations of Neutral Gas Origins)
Studying neutral hydrogen gas is important for understanding our Universe. Made up of one proton and one electron, this gas has been a fundamental driver of galaxy formation and evolution, from before the birth of first stars to the present day.
DINGO will study the evolution of neutral hydrogen throughout much of the Universe’s history. It will combine the data from ASKAP with that from other telescopes, including the Anglo-Australian Telescope and the GALEX and Herschel space observatories. This collaboration enables a thorough study of the co-evolution of the stars, gas and dark matter content of galaxies.
EMU (Evolutionary Map of the Universe)
ASKAP will sweep the southern sky for EMU, collecting data on nearly all the celestial objects out there. EMU will probe various types of galaxies to the edge of the Universe. In particular, it will search typical star forming galaxies, powerful starburst galaxies and those with large, active black holes at their centre. EMU is likely to discover rare objects in its survey. It has already done this in its pilot phase, with the discovery of odd radio circles and dancing ghosts. The key goals for EMU are to trace the evolution of star forming galaxies and massive black holes throughout the history of the Universe.
Using world-class technology, EMU will create the most sensitive wide-field atlas yet. It will provide data that researchers will refer to for years into the future. For example, a survey completed by the Parkes radio telescope, Murriyang, in 2002 is still offering researchers things to study!
FLASH (First Large Absorption Survey in HI)
As the name suggests, FLASH works almost like a flashlight. It looks for areas where a bright background light filters through lots of hydrogen gas to reach us. By analysing how the light has changed on its journey, FLASH can uncover characteristics of the gas.
Hydrogen gas is the raw material from which new stars are formed within galaxies. We can measure the amount of gas in galaxies and its distribution to understand how galaxies grow and change. FLASH is building a significant amount of data about a time in the Universe’s history that we know very little about – between four and eight billion years ago!
GASKAP-HI (Galactic ASKAP – Neutral Hydrogen)
Using ASKAP’s advanced capabilities, GASKAP-HI will collect brighter, clearer and more detailed data than ever before. This project is detecting and mapping neutral hydrogen gas throughout the Milky Way and neighbouring galaxies, the Magellanic Clouds. From the structures in the gas, GASKAP-HI should be able to trace the effects of stellar winds and supernova explosions. The project will also map the Galactic fountain, in which bubbles of gas rise out of the Milky Way disk. The bubbles then fall back out of the Galactic halo as rain.
We should get some stunning images of the interstellar medium. Then we’ll combine them with images from other telescopes that use other wavelengths, such as the James Webb Space Telescope. We have already seen a taste of things to come with the image of the Small Magellanic Cloud.
GASKAP-OH (Galactic ASKAP – ground-state Hydroxyl)
The flow of matter and energy between stars and the interstellar medium is at the heart of galaxy evolution. GASKAP-OH will help us understand how galaxies process gas into stars and back again. It will do so by observing hydroxyl gas (oxygen and hydrogen molecules) in the Milky Way and Large Magellanic Cloud.
The survey will reveal the formation and early evolution of molecular clouds and young stars, and the end-of-life activities of old massive stars. Producing data at unprecedented sensitivity and resolution, GASKAP-OH will refine our understanding of the structure of the Milky Way Galaxy in the southern sky.
POSSUM (Polarisation Sky Survey of the Universe’s Magnetism)
Understanding the Universe is impossible without understanding magnetic fields. Magnetic fields are key to the Universe, yet it is unclear how large-scale magnetic fields are generated and sustained. POSSUM will produce a wide-field survey of magnetic fields at play in the cosmos. It will have help from ASKAP, using its ability to detect polarised radio waves for the survey.
POSSUM will carry out a comprehensive survey of magnetic fields in galaxies, black holes, galaxy clusters and the intergalactic medium. It will revolutionise our understanding of the Milky Way’s magnetic field while testing ideas on how magnetic fields are generated.
VAST (Variables and Slow Transients)
Variable and transient sources are objects in our Universe that change in brightness. They flash or flicker or turn off and on. They are usually a sign that extreme or interesting physics is going on. By looking for these changing sources we can discover new types of astronomical objects. VAST has already discovered the brightest ever pulsar and a mysterious signal from the centre of the galaxy. That was just during its pilot study. Imagine what it will discover at full capacity!
VAST searches the sky for transient objects with a timescale as short as ten seconds. ASKAP’s wide-field survey capabilities will enable the discovery and investigation of variable and transient objects from our own Galaxy and beyond. These include as flare stars, intermittent pulsars, ultra-magnetised pulsars called magnetars, supernovae gamma-ray bursts and stars that were torn apart by supermassive black holes. VAST also finds sources that do not change themselves, but flicker due to effects of gas in our galaxy. VAST will probe unexplored regions where new classes of sources may be detected.
WALLABY (Widefield ASKAP L-Band Legacy All-Sky Blind Survey)
WALLABY will survey over the visible sky, detecting the neutral hydrogen gas beyond our galaxy. This will uncover up to 200,000 galaxies!
The main aims of WALLABY are to examine these galaxies’ distribution and the properties of the hydrogen gas within them. This information can tell us a lot about our Universe. Such as evolution and star formation of galaxies, galaxy interactions and the nature of the cosmic web.
WALLABY will provide the largest, most consistent neutral hydrogen sample of galaxies made yet. It will be an important survey to pave the way for the science pipelines with SKA telescopes. The pilot phase has already provided great results, with a recent data release of galaxies in three dimensions.