‘WTF is that?’ How we’re trawling the Universe for the unknown

The Australian Square Kilometre Array Pathfinder. Credit: Alex Cherney

The Australian Square Kilometre Array Pathfinder. Credit: Alex Cherney

Here’s a challenge: how would you go about finding something if you didn’t know what it was you were looking for?

No, this isn’t an ancient riddle or one of those horrible corporate team building exercises. It’s actually a very real problem being being faced by astronomers using our newest telescope, the Australian SKA Pathfinder (ASKAP).

In order to understand how galaxies form and evolve, the Evolutionary Map of the Universe (EMU) team will take a census of radio sources in the sky. Along the way they expect to find about 70 million galaxies along the way – which is a substantial increase from the 2.5 million we currently know of. But to do so means trawling through, literally, a Universe of data.

“With EMU significantly increasing the volume of phase space we’re observing, it’s more than likely we’re going to stumble across some unexpected new phenomena,” said the project’s Principal Investigator, Ray Norris.

The EMU in the sky. Credit: Barnaby Norris.

The EMU in the sky. Credit: Barnaby Norris.

But with the supercomputer only sifting through data collected according to a specific selection criteria, there is a chance that these phenomena may fall through the cracks and lie undiscovered for decades, until an “open-minded researcher” suddenly recognises something odd in the data.

The truth is out there, but how would the team find it?

Well, we can tell you how: by developing a cloud computing platform that learns how to stumble across unexpected bits of science that would otherwise be ignored.

“We had a huge opportunity to analyse the data to look for outliers that might point to some new and interesting discovery, so we looked to cloud computing as a way to mine the massive amounts of data looking for any hidden gems.”

The result is the Widefield ouTlier Finder (WTF), a project to develop data mining techniques that search for phenomena beyond the limits of current astronomical knowledge.

Ray says there are three types of outliers they’re looking for. “First are the artefacts, which are important for our quality control, then there are the statistical outliers which are interesting, but the most important are the third kind of outliers – the entirely unexpected bits of science, the ones that make us stop and say – WTF?”.

The complexity of the newest telescopes like ASKAP means that we can’t just hope to simply stumble across new phenomena, we have to actively look for it by whatever means we can, or else we’ll end up missing the most exciting science results of the future.”

A colourful representation of the EMU sky coverage. The area in the top left is the part of the sky not covered by EMU.

A colourful representation of the EMU sky coverage. The area in the top left is the part of the sky not covered by EMU.

WTF’s cloud-based backend is hosted on Amazon Web Services servers, where the researchers are able to access software for data reduction, calibration and viewing right from their desktop. The team is currently issuing a challenge using data peppered with “EMU (Easter) Eggs” – objects that might pose a challenge to data mining algorithms. This way they hope to train the system to recognise things that systematically depart from known categories of astronomical objects, to help better prepare for unanticipated discoveries that would otherwise remain hidden.

EMU has received a grant to develop a cloud computing platform for machine learning as part of the AstroCompute in the Cloud collaboration, driven by Amazon Web Services (AWS) and the SKA Telescope. The collaboration is intended to accelerate the development of innovative tools and techniques for processing, storing and analysing the global astronomy community’s vast amounts of astronomic data in the cloud.

For more information about ASKAP, visit our website.


Make our ASKAP telescope a star of the night sky

By Emily Lehmann

There’s a new star in the making in the world of astronomy, with our Australian Square Kilometre Array Pathfinder (ASKAP) named as a finalist in The Australian Innovation Challenge’s Manufacturing, Construction and Infrastructure category*.

We recently shared some of the first images produced  by the amazing ASKAP telescope. It comprises a cluster of 36 radio dishes that work in conjunction with a powerful supercomputer to form what is, in effect, a single composite radio telescope a massive six kilometres across.

This allows it to survey the night sky very quickly, taking panoramic snapshots over 100 times the size of the full moon (as viewed from Earth, of course!).

One of the ASKAP radio dishes, located in a remote area of Western Australia.

One of the ASKAP radio dishes, located in a remote area of Western Australia.

The world-leading facility is revolutionising astronomy, and this award nomination is a welcome recognition. You can vote for it here – just scroll down to the bottom of the page.

Now, for all you space cadets, here’s five astronomical facts about why ASKAP is out of this world and a sure-fire winner:

  1. ASKAP’s 36 radio dishes, each 12 metres in diameter, give it the capacity to scan the whole sky and make it sensitive to whisper-quiet signals from the Milky Way.
  2. ASKAP is an outstanding telescope in its own right, as well as a technology demonstrator for the Square Kilometre Array (SKA). This pioneering technology will make ASKAP the fastest radio telescope in the world for surveying the sky.
  3. Once built, the SKA will comprise of a vast army of radio receivers distributed over tens to hundreds of kilometres in remote areas of Western Australia and Africa.
  4. The SKA will generate five million million bytes of information in its first day. That’s almost as many grains of sand on all of the world’s beaches.
  5. ASKAP is located in the remote Murchison Shire of Western Australia, which was chosen because there is hardly any human activity and so little background radio noise.

ASKAP is one of four CSIRO projects already in the running for different categories in the Oz’s Innovation Challenge (we’ve also written about swarm sensing and Direct Nickel). You can #voteCSIRO for any and all of them – just follow the links from the Challenge’s home page!


Australia’s astronomy future in a climate of cutbacks

Parkes radio telescope

What future for the Parkes radio telescope amid the CSIRO cutbacks? Image: Wayne England

By Lewis Ball, CSIRO

The future looks very bright for Australian radio astronomy but it was somewhat clouded earlier this year when CSIRO’s radio astronomy program took a dramatic hit in the Australian federal budget.

CSIRO has cut its funding for radio astronomy by 15%, down A$3.5 million to A$17 million for the 2014-15 financial year. The result will be a reduction of about 30 staff from the plan of just three months ago.

The cuts will impact most heavily on CSIRO’s in-house astronomy research, on the operation of the Parkes radio telescope – instantly recognisable from the movie The Dish – on the less well known but tremendously productive Australia Telescope Compact Array near Narrabri and on the Mopra Telescope near Coonabarabran, all in New South Wales.

The Australia Telescope Compact Array.

The Australia Telescope Compact Array. Image: D. Smyth

About two-thirds of ATNF’s staffing reduction will be effected through not filling planned new roles, most prominent of which was to be a CSIRO “SKA Chief Scientist”. A third of the reduction will be through involuntary redundancies. Eight staff across sites in Sydney, Parkes, Narrabri and Geraldton have already been informed that their roles are expected to cease.

The speed of implementation of such a substantial funding reduction forces swift action. This has unsettled staff and the broader astronomy community, but it hasn’t changed the broad direction of CSIRO’s astronomy program.

World leaders in radio astronomy

Australian scientists and engineers are world leaders in radio astronomy, both in understanding our universe and in developing some of the most innovative technologies used to gain that understanding, and have been for 50 years.

CSIRO’s Australia Telescope National Facility (ATNF) has been integral to the discovery of the first double pulsar system (a long-sought holy grail of astronomy), the identification of a previously unknown arm of our own galaxy, the Milky Way, and the invention of Wi-Fi now so embedded in everyday communications.

For the past decade CSIRO has been steadily changing the way it operates its radio astronomy facilities. CSIRO’s highest priority is the pursuit of science enabled by the development of an innovative new technology that provides an unprecedented wide field of view.

This uses “Phased Array Feeds” (PAFs) as multi-pixel radio cameras at the focus of dishes. PAFs are being deployed in the Australian SKA Pathfinder (ASKAP), in Western Australia, which will be the fastest radio telescope in the world for surveying the sky.

ASKAP telescopes in WA

High-speed radio astronomy surveys will be possible thanks to the PAF receivers (green chequerboard at top of the quadrupod) on the ASKAP telescopes in Western Australia.

ASKAP is in the early stages of commissioning. It is just now starting to demonstrate the new capabilities obtainable with a PAF-equipped array.

ASKAP is an outstanding telescope in its own right but is also a pathfinder to the huge Square Kilometre Array (SKA). This enormous project will build the world’s biggest astronomy observatory in Australia and southern Africa. It’s also the most expensive at a cost of around A$2.5 billion.

Cutbacks at The Dish

To resource these exciting developments, CSIRO has been reducing costs and staffing at its existing facilities, including the venerable Parkes Dish. This is a painful but necessary process. The most recent funding cuts will result in more pain.

Astronomers will no longer have the option of travelling to the Compact Array to operate the telescope to collect their data. They can run the telescope from CSIRO’s operations centre in Sydney, or from their own university, or from anywhere in the world via an internet connection.

Astronomers who use the Parkes telescope have been doing this for the past year after a very successful program to make the 50-year-old dish remotely operable. That is pretty amazing for a machine built before the advent of modern computers.

Parkes telescope

The Parkes dish gets the remote treatment.
Image: John Sarkissian

For many decades Parkes staff have swapped detector systems or “radio receivers” in and out of the focus cabin, the box at the tip of the tripod that sits about 64 metres off the ground. Each receiver operates at different wavelengths and offers quite different types of science.

It seems likely that CSIRO will offer just two Parkes receivers for at least the next six to 12 months, since it will no longer have the staff needed to swap receivers. Similar reductions in the capability of the Compact Array will also be needed to fit within the budget.

The future

While the current changes are painful, the future is incredibly exciting. The direction of Australia’s astronomy is described in the Decadal Plan for Australian Astronomy for 2006–2015. It identifies participation in the SKA and access to the world’s largest optical telescopes as the two highest priorities for Australian astronomy.

We are making progress on both fronts, despite some significant challenges. The process to develop the plan for the next decade is well in hand under the stewardship of the National Committee for Astronomy.

Phased arrays are also at the heart of the Murchison Widefield Array (MWA), another innovative SKA precursor that has been in operation for a little over a year.

ASKAP and the MWA are located in the Murchison region of Western Australia, chosen because it has a tremendously low level of human activity and so astonishingly little background radio noise.

This radio quietness is the equivalent of the dark skies so important for optical astronomers. Less noise means astronomers are better able to detect and study the incredibly weak radio signals from the most distant parts of the universe.

This freedom from radio interference is a unique resource available only in remote parts of Australia and is essential for ASKAP, MWA and much of the science targeted by the SKA.

PAFs

Prototype of the more sensitive second-generation PAFs to be deployed on ASKAP undergoing tests in Western Australia in August 2014.
Image: A. Hotan

The wide fields of view of ASKAP and the MWA enable unprecedented studies of the entire radio sky. Astronomers will measure the radio emission of millions of galaxies and complete massive surveys that for the first time will connect radio astronomy to the more mature field of optical astronomy.

Mapping the sky with EMU and WALLABY

The two highest priority projects for ASKAP are called the Evolutionary Map of the Universe (EMU) and the Widefield ASKAP L-Band Legacy All-Sky Blind Survey (WALLABY).

Both will survey millions of galaxies and together they will trace the formation and evolution of stars, galaxies and massive black holes to help us explore the large-scale structure of the universe.

The MWA is already producing great science targeted at the detection of intergalactic hydrogen gas during what’s known as the “epoch of reionisation” when the first stars in the universe began to shine.

With the SKA we aim to understand what the mysterious dark matter and dark energy are. We may also provide another spin-off such as the Wi-Fi technology, which came from CSIRO efforts to detect the evaporating black holes predicted by Stephen Hawking.

Advances in data-mining or processing techniques driven by the astonishing data rates that will be collected by the thousands of SKA antennas deployed across the Australian and African continents might provide the most fertile ground of all, illustrating once again the long-term benefits of investing in cutting-edge science.

Lewis Ball has received funding from the Australian Research Council. CSIRO Astronomy and Space Science receives funding from a variety of government sources, and from NASA/JPL.

This article was originally published on The Conversation.
Read the original article.


The first images from ASKAP reveal slices through space

Three of the dishes used by the Australian Square Kilometre Array Pathfinder telescope.

Three of the dishes used by the Australian Square Kilometre Array Pathfinder telescope. Image: CSIRO / Terrace Photographers

By Lisa Harvey-Smith, CSIRO

The first images from Australia’s Square Kilometre Array Pathfinder (ASKAP) telescope have given scientists a sneak peek at the potential images to come from the much larger Square Kilometre Array (SKA) telescope currently being developed.

ASKAP comprises a cluster of 36 large radio dishes that work together with a powerful supercomputer to form (in effect) a single composite radio telescope 6km across.

What makes ASKAP truly special is the wide-angle “radio cameras”, known as phased array feeds, which can take up to 36 images of the sky simultaneously and stitch them together to generate a panoramic image.

Why panoramic vision?

Traditional radio telescope arrays such as the Australia Telescope Compact Array near Narrabri, NSW, are powerful probes of deep-space objects. But their limited field of view (approximately equivalent to the full moon) means that undertaking major research projects such as studying the structure of the Milky Way, or carrying out a census of millions of galaxies, is slow, painstaking work that can take many years to realise.

The special wide-angle radio receivers on ASKAP will increase the telescope’s field of vision 30 times, allowing astronomers to build up an encyclopedic knowledge of the sky.

This technological leap will enable us to study many astrophysical phenomena that are currently out of reach, including the evolution of galaxies and cosmic magnetism over billions of years.

For the past 12 months a team of CSIRO astronomers has been testing these novel radio cameras fitted on a test array of six antennas.

The first task for the team was to test the ability of the cameras to image wide fields-of-view and thus demonstrate ASKAP’s main competitive advantage. The results were impressive!

A wide-field image of the sky taken with the ASKAP test array.

A wide-field image of the sky taken with the ASKAP test array. Image: I. Heywood/ACES team, CSIRO

One of the first test images from the ASKAP test array is seen above. The hundreds of star-like points are actually galaxies, each containing billions of stars, seen in radio waves. Using CSIRO’s new radio cameras, nine overlapping images were taken simultaneously and stitched together.

The resulting image covers an area of sky more than five times greater than is normally visible with a radio telescope. The information contained in such images will help us to rapidly build up a picture of the evolution of galaxies over several billion years.

Where next for ASKAP to look

On the back of this success, the commissioning team turned the telescope to the Sculptor or “silver coin” galaxy to test its ability to study deep-space objects.

Sculptor is a spiral galaxy like our own Milky Way, but appears elongated as it is seen almost edge-on from earth.

The Sculptor galaxy seen rotating edge-on using the ASKAP test array.

The Sculptor galaxy seen rotating edge-on using the ASKAP test array. Image: P. Serra/ACES Team, CSIRO

This image (above) shows the radio waves emitted by hydrogen gas that is swirling in an almost circular motion around the galaxy as it rotates.

The red side of the galaxy is moving away from us and the blue side is moving towards us. The speed of rotation tells us the galaxy’s mass.

The team has also tested the ability of the telescope to “weigh” the gas in very distant galaxies. The image (below) shows a grouping of overlapping galaxies called a gravitational lens.

Gravitational lens image

A cluster of galaxies aligned to form a ‘gravitational lens’ was captured using ASKAP’s test array.

Seven billion years ago, radio waves from a distant galaxy were absorbed by a foreground galaxy in this group. That signal was processed by ASKAP to form the spectrum (top right in the above image).

Although not visually pretty, this type of observation has enormous scientific value, allowing astronomers to understand how quickly galaxies use up their star-forming fuel.

The latest demonstration with the ASKAP test array is a movie (below) of layers through a cloud of gas in our Milky Way.

This series of images – similar to an MRI scan imaging slices through the human body – demonstrates the ability of the telescope to measure the intricate motions of the spiral arms of the Milky Way and other galaxies.

Building to the bigger array

These images are just the beginning of a new era in radio astronomy, starting with SKA pathfinders like ASKAP and culminating in the construction of the SKA radio telescope.

Once built, the SKA will comprise a vast army of radio receivers distributed over tens to hundreds of kilometres in remote areas of Western Australia and South Africa.

Just like ASKAP combines signals from several dishes, the SKA will use a supercomputer to build up a composite image of the sky.

Each ensemble of antennas will work together to photograph distant astronomical objects that are so faint, that they can’t be seen at all with current technology.

The SKA will thereby open up vast tracts of unexplored space to scientific study, making it a game-changer in astrophysical and cosmological research.

This article was originally published on The Conversation.
Read the original article.


New chapter for radio astronomy begins… right now!

ASKAP

ASKAP will help scientists to tackle some of the biggest questions in radio astronomy. Image: Alex Cherney

By Lisa Harvey-Smith, CSIRO

Today, after several years of design and construction, CSIRO’s Australian Square Kilometre Array Pathfinder (ASKAP) is officially open.

The A$140m facility, built in the remote Murchison Shire of Western Australia, has a dual role as a cutting-edge radio telescope to study the universe and as a technology demonstrator for the planned A$2 billion Square Kilometre Array (SKA).

ASKAP comprises 36 radio dishes, each with a diameter of 12 metres, making the telescope sensitive to faint radiation from the Milky Way and giving it the ability to detect very distant galaxies. It is also a remarkably complex telescope.

A new receiver technology called a phased array feed, developed in Australia by CSIRO, gives ASKAP an unrivalled capability to survey large volumes of the cosmos.

These special cameras increase the area of sky visible to the telescope at any one time by a factor of 30 over existing technology. This increases the scale of the resulting photographs of the radio sky from the size of the full moon to an area larger than the Southern Cross.

The addition of this wide-angle camera boosts the survey speed of ASKAP, allowing astronomers to carry out large “drift-net” surveys, to trawl the sky and gather information on hundreds of millions of galaxies.

By working in this way, the telescope is able to tackle big-ticket research areas such as cosmology and dark energy and gather enough statistical information to study the fascinating life stories of galaxies.

ASKAP

It’s been several long years of design and construction, but ASKAP is open for business. Image: Alex Cherney

Researchers from around the world are already lining up to use the facility with ten ASKAP science survey teams, totalling more than 700 astronomers, ready and waiting.

These teams are working with CSIRO to design and maximise the scientific value of the surveys, some of which will take around two years to complete. Science verification has begun and some science projects are expected to be underway by the end of 2013.

CSIRO and the science teams are also tackling head-on the challenges involved in extracting – in real-time – scientific knowledge from an extremely large (72 Terabit per second) raw data stream. That’s enough to fill 120 million Blu-ray discs per day.

Dealing with such data volumes is something radio astronomers will have to get used to. In the era of the SKA we will find ourselves interacting less with real telescopes and more often mining online data stores and “virtual observatories”. Not only is the technology changing, the way in which we do our science is also being transformed.

One of the aims of the SKA Pathfinders (the others being the MeerKAT facility in South Africa and the Murchison Widefield Array) is to ensure the next generation of astronomers is ready for this new challenge.

The official opening of ASKAP and the Murchison Radio-astronomy Observatory (MRO) marks the beginning of a new chapter for radio astronomy in Australia. Following the announcement earlier this year of a dual-site arrangement for the SKA, we now know the MRO will host two complementary astronomical instruments during Phase 1 of the project.

One will study low-frequency radio waves emanating from cold gas in the early universe and will build on the scientific and technical expertise gained from the Murchison Widefield Array project. The other will be an array of almost 100 dishes built on the capabilities of ASKAP. This instrument will be used to survey unprecedented volumes of our universe and delve even deeper into it’s secrets.

Over the coming decade the number and capabilities of telescopes available to radio astronomers will grow enormously. Along with the Murchison Widefield Array, ASKAP is leading the way in prototyping cutting-edge SKA technologies at the most radio-quiet observatory on Earth.

It truly is an exciting time to be a radio astronomer!

CSIRO acknowledges the Wajarri Yamatji people as the traditional owners of the land on which the observatory was built.

Lisa Harvey-Smith works for CSIRO and is project scientist for ASKAP.

The Conversation

This article was originally published at The Conversation.
Read the original article.


Keeping our eyes on the stars (and feet on the ground)

We’re busily preparing to show off our shiny new telescope, the Australian SKA Pathfinder, to the world. To mark the end of its construction, the telescope will be formally opened next Friday, 5 October. This time-lapse video shows the telescope’s 36 antennas standing tall in the breathtaking Western Australian landscape.

The antennas will begin making detailed pictures of distant galaxies in 2013. ASKAP has been designed to be able to survey the whole sky extremely quickly, providing the opportunity for astronomy projects never done before. Check out the ASKAP webcam or homepage for more information.

Next Friday also marks the official opening of the Murchison Radio-astronomy Observatory (MRO), where ASKAP is located.

CSIRO acknowledges the Wajarri Yamatji people as the traditional owners of the MRO site.