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  • richardmitnick 1:55 pm on November 11, 2018 Permalink | Reply
    Tags: ASKAP-Australia Square Kilometre Array Pathfinder, , , , , , , ICRAR, Murchison Radio-astronomy Observatory (MRO) in Western Australia,   

    From International Centre for Radio Astronomy Research: “Aussie telescope almost doubles known number of mysterious ‘fast radio bursts’” 

    ICRAR Logo
    From International Centre for Radio Astronomy Research

    October 11, 2018
    Dr Ryan Shannon
    Swinburne University of Technology
    & OzGrav ARC Centre of Excellence
    +61 3 9214 5205
    rshannon@swin.edu.au

    Dr Jean-Pierre Macquart —
    ICRAR / Curtin University
    +61 8 9266 9248
    jean-pierre.macquart@icrar.org

    Dr Keith Bannister
    CSIRO
    +61 2 9372 4295
    keith.bannister@csiro.au

    Pete Wheeler —
    Media Contact, ICRAR
    Ph: +61 423 982 018
    pete.wheeler@icrar.org

    October 11, 2018

    Australian researchers using a CSIRO radio telescope in Western Australia have nearly doubled the known number of ‘fast radio bursts’— powerful flashes of radio waves from deep space.
    The team’s discoveries include the closest and brightest fast radio bursts ever detected. Their findings were reported today in the journal Nature.

    Fast radio bursts come from all over the sky and last for just milliseconds. Scientists don’t know what causes them but it must involve incredible energy—equivalent to the amount released by the Sun in 80 years. “We’ve found 20 fast radio bursts in a year, almost doubling the number detected worldwide since they were discovered in 2007,” said lead author Dr Ryan Shannon, from Swinburne University of Technology and the OzGrav ARC Centre of Excellence.

    “Using the new technology of the Australia Square Kilometre Array Pathfinder (ASKAP), we’ve also proved that fast radio bursts are coming from the other side of the Universe rather than from our own galactic neighbourhood.”

    Australian Square Kilometre Array Pathfinder (ASKAP) is a radio telescope array located at Murchison Radio-astronomy Observatory (MRO) in the Australian Mid West. ASKAP consists of 36 identical parabolic antennas, each 12 metres in diameter, working together as a single instrument with a total collecting area of approximately 4,000 square metres.

    1
    For each burst, the top panels show what the FRB signal looks like when averaged over all frequencies. The bottom panels show how the brightness of the burst changes with frequency. The bursts are vertical because they have been corrected for dispersion. Credit: Ryan Shannon and the CRAFT collaboration.

    Co-author Dr Jean-Pierre Macquart, from the Curtin University node of the International Centre for Radio Astronomy Research (ICRAR), said bursts travel for billions of years and occasionally pass through clouds of gas. “Each time this happens, the different wavelengths that make up a burst are slowed by different amounts,” he said. “Eventually, the burst reaches Earth with its spread of wavelengths arriving at the telescope at slightly different times, like swimmers at a finish line. “Timing the arrival of the different wavelengths tells us how much material the burst has travelled through on its journey. “And because we’ve shown that fast radio bursts come from far away, we can use them to detect all the missing matter located in the space between galaxies—which is a really exciting discovery.”

    CSIRO’s Dr Keith Bannister, who engineered the systems that detected the bursts, said ASKAP’s phenomenal discovery rate is down to two things. “The telescope has a whopping field of view of 30 square degrees, 100 times larger than the full Moon,” he said. “And, by using the telescope’s dish antennas in a radical way, with each pointing at a different part of the sky, we observed 240 square degrees all at once—about a thousand times the area of the full Moon. “ASKAP is astoundingly good for this work.”

    Dr Shannon said we now know that fast radio bursts originate from about halfway across the Universe but we still don’t know what causes them or which galaxies they come from.
    The team’s next challenge is to pinpoint the locations of bursts on the sky. “We’ll be able to localise the bursts to better than a thousandth of a degree,” Dr Shannon said.
    “That’s about the width of a human hair seen ten metres away, and good enough to tie each burst to a particular galaxy.”

    ASKAP is located at CSIRO’s Murchison Radio-astronomy Observatory (MRO) in Western Australia, and is a precursor for the future Square Kilometre Array (SKA) telescope.

    SKA Murchison Widefield Array, Boolardy station in outback Western Australia, at the Murchison Radio-astronomy Observatory (MRO)

    The SKA could observe large numbers of fast radio bursts, giving astronomers a way to study the early Universe in detail.

    CSIRO acknowledges the Wajarri Yamaji as the traditional owners of the MRO site.

    A fast radio burst leaves a distant galaxy, travelling to Earth over billions of years and occasionally passing through clouds of gas in its path. Each time a cloud of gas is encountered, the different wavelengths that make up a burst are slowed by different amounts. Timing the arrival of the different wavelengths at a radio telescope tells us how much material the burst has travelled through on its way to Earth and allows astronomers to to detect “missing” matter located in the space between galaxies. Credit: CSIRO/ICRAR/OzGrav/Swinburne University of Technology

    Dr Ryan Shannon (Swinburne/OzGrav), Dr Jean-Pierre Macquart (Curtin/ICRAR) and Dr Keith Bannister (CSIRO) describe their discovery of 20 new fast radio bursts (FRBs) and how the Phased Array Feed (PAF) receiver technology in CSIRO’s Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope enabled this breakthrough science. Credit: CSIRO.

    More Information:
    ASKAP

    The Australian Square Kilometre Array Pathfinder (ASKAP) is the world’s fastest survey radio telescope. Designed and engineered by CSIRO, ASKAP is made up of 36 ‘dish’ antennas, spread across a 6km diameter, that work together as a single instrument called an interferometer. The key feature of ASKAP is its wide field of view, generated by its unique phased array feed (PAF) receivers. Together with specialised digital systems, the PAFs create 36 separate (simultaneous) beams on the sky which are mosaicked together into a large single image.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    ICRAR is an equal joint venture between Curtin University and The University of Western Australia with funding support from the State Government of Western Australia. The Centre’s headquarters are located at UWA, with research nodes at both UWA and the Curtin Institute for Radio Astronomy (CIRA).
    ICRAR has strong support from the government of Australia and is working closely with industry and the astronomy community, including CSIRO and the Australian Telescope National Facility, <a
    ICRAR is:

    Playing a key role in the international Square Kilometre Array (SKA) project, the world's biggest ground-based telescope array.

    Attracting some of the world’s leading researchers in radio astronomy, who will also contribute to national and international scientific and technical programs for SKA and ASKAP.
    Creating a collaborative environment for scientists and engineers to engage and work with industry to produce studies, prototypes and systems linked to the overall scientific success of the SKA, MWA and ASKAP.

    Murchison Widefield Array,SKA Murchison Widefield Array, Boolardy station in outback Western Australia, at the Murchison Radio-astronomy Observatory (MRO)

    A Small part of the Murchison Widefield Array

    Enhancing Australia’s position in the international SKA program by contributing to the development process for the SKA in scientific, technological and operational areas.
    Promoting scientific, technical, commercial and educational opportunities through public outreach, educational material, training students and collaborative developments with national and international educational organisations.
    Establishing and maintaining a pool of emerging and top-level scientists and technologists in the disciplines related to radio astronomy through appointments and training.
    Making world-class contributions to SKA science, with emphasis on the signature science themes associated with surveys for neutral hydrogen and variable (transient) radio sources.
    Making world-class contributions to SKA capability with respect to developments in the areas of Data Intensive Science and support for the Murchison Radio-astronomy Observatory.

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  • richardmitnick 6:38 am on March 14, 2018 Permalink | Reply
    Tags: Astronomers discover galaxies spin like clockwork, , , Australia's Science Channel, , , ICRAR   

    From Australia’s Science Channel via ICRAR: “Astronomers discover galaxies spin like clockwork” 

    Or is it from ICRAR via Australia’s Science Channel?

    1

    ICRAR Logo
    International Centre for Radio Astronomy Research

    March 14, 2018
    No writer credit

    From the biggest to the smallest, galaxies all rotate at the same rate.

    2
    This Hubble image reveals the gigantic Pinwheel galaxy, Messier 101, one of the best known examples of “grand design spirals”, and its supergiant star-forming regions in unprecedented detail. The image is the largest and most detailed photo of a spiral galaxy ever released from Hubble. Credit: NASA/ESA HUbble

    NASA/ESA Hubble Telescope

    The Earth spinning around on its axis once gives us the length of a day, and a complete orbit of the Earth around the Sun gives us a year.

    “It’s not Swiss watch precision,” said Professor Gerhardt Meurer from the UWA node of the International Centre for Radio Astronomy Research (ICRAR). “But regardless of whether a galaxy is very big or very small, if you could sit on the extreme edge of its disk as it spins, it would take you about a billion years to go all the way round.”

    Professor Meurer said that by using simple maths, you can show all galaxies of the same size have the same average interior density.

    “Discovering such regularity in galaxies really helps us to better understand the mechanics that make them tick — you won’t find a dense galaxy rotating quickly, while another with the same size but lower density is rotating more slowly,” he said.

    Professor Meurer and his team also found evidence of older stars existing out to the edge of galaxies.

    “Based on existing models, we expected to find a thin population of young stars at the very edge of the galactic disks we studied,” he said.

    “But instead of finding just gas and newly formed stars at the edges of their disks, we also found a significant population of older stars along with the thin smattering of young stars and interstellar gas.”

    “This is an important result because knowing where a galaxy ends means we astronomers can limit our observations and not waste time, effort and computer processing power on studying data from beyond that point,” said Professor Meurer. “So because of this work, we now know that galaxies rotate once every billion years, with a sharp edge that’s populated with a mixture of interstellar gas, with both old and young stars.”

    Professor Meurer said that the next generation of radio telescopes, like the soon-to-be-built Square Kilometre Array (SKA), will generate enormous amounts of data, and knowing where the edge of a galaxy lies will reduce the processing power needed to search through the data.

    SKA Square Kilometer Array

    “When the SKA comes online in the next decade, we’ll need as much help as we can get to characterise the billions of galaxies these telescopes will soon make available to us.”

    The research has been published in The Monthly Notices of the Royal Astronomical Society.

    See the full article here .

    Please help promote STEM in your local schools.
    STEM Icon

    Stem Education Coalition

    ICRAR is an equal joint venture between Curtin University and The University of Western Australia with funding support from the State Government of Western Australia. The Centre’s headquarters are located at UWA, with research nodes at both UWA and the Curtin Institute for Radio Astronomy (CIRA).
    ICRAR has strong support from the government of Australia and is working closely with industry and the astronomy community, including CSIRO and the Australian Telescope National Facility, <a
    ICRAR is:

    Playing a key role in the international Square Kilometre Array (SKA) project, the world's biggest ground-based telescope array.

    Attracting some of the world’s leading researchers in radio astronomy, who will also contribute to national and international scientific and technical programs for SKA and ASKAP.
    Creating a collaborative environment for scientists and engineers to engage and work with industry to produce studies, prototypes and systems linked to the overall scientific success of the SKA, MWA and ASKAP.

    Murchison Widefield Array,SKA Murchison Widefield Array, Boolardy station in outback Western Australia, at the Murchison Radio-astronomy Observatory (MRO)

    A Small part of the Murchison Widefield Array

    Enhancing Australia’s position in the international SKA program by contributing to the development process for the SKA in scientific, technological and operational areas.
    Promoting scientific, technical, commercial and educational opportunities through public outreach, educational material, training students and collaborative developments with national and international educational organisations.
    Establishing and maintaining a pool of emerging and top-level scientists and technologists in the disciplines related to radio astronomy through appointments and training.
    Making world-class contributions to SKA science, with emphasis on the signature science themes associated with surveys for neutral hydrogen and variable (transient) radio sources.
    Making world-class contributions to SKA capability with respect to developments in the areas of Data Intensive Science and support for the Murchison Radio-astronomy Observatory.

     
  • richardmitnick 10:15 am on February 15, 2018 Permalink | Reply
    Tags: , , , , ICRAR, Milky Way and Andromeda merger   

    From ICRAR: “Milky Way ties with neighbour in galactic arms race” 

    ICRAR Logo
    International Centre for Radio Astronomy Research

    February 15, 2018
    CONTACT INFORMATION
    Dr Prajwal Kafle (ICRAR /
    The University of Western Australia)
    Ph: +61 6488 7203
    E: Prajwal.Kafle@icrar.org

    Pete Wheeler (Media Contact, ICRAR)
    Ph: +61 423 982 018
    E: Pete.Wheeler@icrar.org

    Astronomers have discovered that our nearest big neighbour, the Andromeda galaxy, is roughly the same size as the Milky Way.

    It had been thought that Andromeda was two to three times the size of the Milky Way, and that our own galaxy would ultimately be engulfed by our bigger neighbour.

    But the latest research, published today [MNRAS] , evens the score between the two galaxies.

    Milky Way Galaxy Credits: NASA/JPL-Caltech/R. Hurt

    Andromeda Galaxy NASA/ESA Hubble

    1
    The Milky Way and Andromeda. Credit: ICRAR

    It found the weight of the Andromeda is 800 billion times heavier than the Sun, on par with the Milky Way.

    Astrophysicist Dr Prajwal Kafle, from The University of Western Australia node of the International Centre for Radio Astronomy Research, said the study used a new technique to measure the speed required to escape a galaxy.

    “When a rocket is launched into space, it is thrown out with a speed of 11km/s to overcome the Earth’s gravitational pull,” he said.

    “Our home galaxy, the Milky Way, is over a trillion times heavier than our tiny planet Earth so to escape its gravitational pull we have to launch with a speed of 550km/s.

    “We used this technique to tie down the mass of Andromeda.”

    Dr Kafle said the research suggests scientists previously overestimated the amount of dark matter in the Andromeda galaxy.

    “By examining the orbits of high speed stars, we discovered that this galaxy has far less dark matter than previously thought, and only a third of that uncovered in previous observations,” he said.

    The Milky Way and Andromeda are two giant spiral galaxies in our local Universe, and light takes a cosmologically tiny two million years to get between them.

    With Andromeda no longer considered the Milky Way’s big brother, new simulations are needed to find out what will happen when the two galaxies eventually collide.

    Dr Kafle used a similar technique to revise down the weight of the Milky Way in 2014, and said the latest finding had big implications for our understanding of our nearest galactic neighbours.

    “It completely transforms our understanding of the local group,” he said.

    “We had thought there was one biggest galaxy and our own Milky Way was slightly smaller but that scenario has now completely changed.

    “It’s really exciting that we’ve been able to come up with a new method and suddenly 50 years of collective understanding of the local group has been turned on its head.”

    University of Sydney astrophysicist Professor Geraint Lewis said it was exciting to be at a time when the data was getting so good.

    “We can put this gravitational arms race to rest,” he said.

    2
    The Milky Way and Andromeda prior to the merger. Credit: ICRAR

    3
    The Milky Way and Andromeda during the merger. Credit: ICRAR

    See the full article here .

    Please help promote STEM in your local schools.
    STEM Icon

    Stem Education Coalition

    ICRAR is an equal joint venture between Curtin University and The University of Western Australia with funding support from the State Government of Western Australia. The Centre’s headquarters are located at UWA, with research nodes at both UWA and the Curtin Institute for Radio Astronomy (CIRA).
    ICRAR has strong support from the government of Australia and is working closely with industry and the astronomy community, including CSIRO and the Australian Telescope National Facility, <a
    ICRAR is:

    Playing a key role in the international Square Kilometre Array (SKA) project, the world's biggest ground-based telescope array.

    Attracting some of the world’s leading researchers in radio astronomy, who will also contribute to national and international scientific and technical programs for SKA and ASKAP.
    Creating a collaborative environment for scientists and engineers to engage and work with industry to produce studies, prototypes and systems linked to the overall scientific success of the SKA, MWA and ASKAP.

    Murchison Widefield Array,SKA Murchison Widefield Array, Boolardy station in outback Western Australia, at the Murchison Radio-astronomy Observatory (MRO)

    A Small part of the Murchison Widefield Array

    Enhancing Australia’s position in the international SKA program by contributing to the development process for the SKA in scientific, technological and operational areas.
    Promoting scientific, technical, commercial and educational opportunities through public outreach, educational material, training students and collaborative developments with national and international educational organisations.
    Establishing and maintaining a pool of emerging and top-level scientists and technologists in the disciplines related to radio astronomy through appointments and training.
    Making world-class contributions to SKA science, with emphasis on the signature science themes associated with surveys for neutral hydrogen and variable (transient) radio sources.
    Making world-class contributions to SKA capability with respect to developments in the areas of Data Intensive Science and support for the Murchison Radio-astronomy Observatory.

     
  • richardmitnick 9:53 am on December 21, 2017 Permalink | Reply
    Tags: , , , , , , ICRAR, , Telescopes team up to study giant galaxy   

    From ICRAR: “Telescopes team up to study giant galaxy” 

    ICRAR Logo
    International Centre for Radio Astronomy Research

    December 12, 2017 [Just today in social media.]

    CONTACT INFORMATION

    Dr Ben McKinley (ICRAR / Curtin University / CAASTRO)
    Ph: +61 424 871 986
    E: Ben.Mckinley@icrar.org

    Professor Steven Tingay (ICRAR / Curtin University)
    Ph: +61 401 103 635
    E: Steven.Tingay@icrar.org

    Pete Wheeler (Media Contact, ICRAR)
    Ph: +61 423 982 018
    E: Pete.Wheeler@icrar.org

    Astronomers have used two Australian radio telescopes and several optical telescopes to study complex mechanisms that are fuelling jets of material blasting away from a black hole 55 million times more massive than the Sun.

    In research published today [MNRAS], the international team of scientists used the telescopes to observe a nearby radio galaxy known as Centaurus A.

    1
    A close-up view of Centaurus A and the location of a black hole 55 million times more massive than the Sun. Credit: ICRAR/Curtin.

    “As the closest radio galaxy to Earth, Centaurus A is the perfect ‘cosmic laboratory’ to study the physical processes responsible for moving material and energy away from the galaxy’s core,” said Dr Ben McKinley from the International Centre for Radio Astronomy Research (ICRAR) and Curtin University in Perth, Western Australia.

    Centaurus A is 12 million light-years away from Earth—just down the road in astronomical terms—and is a popular target for amateur and professional astronomers in the Southern Hemisphere due to its size, elegant dust lanes, and prominent plumes of material.

    2
    The giant radio galaxy Centaurus A as observed by the Murchison Widefield Array telescope. Credit ICRAR/Curtin.

    Murchison Widefield Array,SKA Murchison Widefield Array, Boolardy station in outback Western Australia, at the Murchison Radio-astronomy Observatory (MRO)

    “Being so close to Earth and so big actually makes studying this galaxy a real challenge because most of the telescopes capable of resolving the detail we need for this type of work have fields of view that are smaller than the area of sky Centaurus A takes up,” said Dr McKinley.

    “We used the Murchison Widefield Array (MWA) and Parkes—these radio telescopes both have large fields of view, allowing them to image a large portion of sky and see all of Centaurus A at once.

    CSIRO/Parkes Observatory, located 20 kilometres north of the town of Parkes, New South Wales, Australia

    The MWA also has superb sensitivity allowing the large-scale structure of Centaurus A to be imaged in great detail,” he said.

    3
    A ‘radio colour’ view of the sky above a ‘tile’ of the Murchison Widefield Array radio telescope, located in outback Western Australia. The Milky Way is visible as a band across the sky and the dots beyond are some of the 300,000 galaxies observed by the telescope for the GLEAM survey. The Centaurus A radio galaxy is visible to the right of the image. Red indicates the lowest frequencies, green the middle frequencies and blue the highest frequencies. Credit: Radio image by Natasha Hurley-Walker (ICRAR/Curtin) and the GLEAM Team. MWA tile and landscape by Dr John Goldsmith / Celestial Visions.

    The MWA is a low frequency radio telescope located at the Murchison Radio-astronomy Observatory in Western Australia’s Mid West, operated by Curtin University on behalf of an international consortium. The Parkes Observatory is a 64-metre radio telescope commonly known as “the Dish” located in New South Wales and operated by CSIRO.

    Observations from several optical telescopes were also used for this work— the Magellan Telescope in Chile, Terroux Observatory in Canberra, and High View Observatory in Auckland [no view available].

    Carnegie 6.5 meter Magellan Baade and Clay Telescopes located at Carnegie’s Las Campanas Observatory, Chile. over 2,500 m (8,200 ft) high

    2
    Terroux Observatory in Canberra, AU

    4
    Centaurus A observed at 2307 MHz by the the Parkes radio telescope, as part of the S-PASS survey. Credit: E. Carretti and the S-PASS team.

    5
    Centaurus A observed at 154 MHz by the Murchison Widefield Array. Credit: ICRAR/Curtin.

    “If we can figure out what’s going in Centaurus A, we can apply this knowledge to our theories and simulations for how galaxies evolve throughout the entire Universe,” said co-author Professor Steven Tingay from Curtin University and ICRAR.

    “As well as the plasma that’s fuelling the large plumes of material the galaxy is famous for, we found evidence of a galactic wind that’s never been seen—this is basically a high speed stream of particles moving away from the galaxy’s core, taking energy and material with it as it impacts the surrounding environment,” he said.

    By comparing the radio and optical observations of the galaxy the team also found evidence that stars belonging to Centaurus A existed further out than previously thought and were possibly being affected by the winds and jets emanating from the galaxy.

    See the full article here .

    Please help promote STEM in your local schools.
    STEM Icon

    Stem Education Coalition

    ICRAR is an equal joint venture between Curtin University and The University of Western Australia with funding support from the State Government of Western Australia. The Centre’s headquarters are located at UWA, with research nodes at both UWA and the Curtin Institute for Radio Astronomy (CIRA).
    ICRAR has strong support from the government of Australia and is working closely with industry and the astronomy community, including CSIRO and the Australian Telescope National Facility, <a
    ICRAR is:

    Playing a key role in the international Square Kilometre Array (SKA) project, the world's biggest ground-based telescope array.

    Attracting some of the world’s leading researchers in radio astronomy, who will also contribute to national and international scientific and technical programs for SKA and ASKAP.
    Creating a collaborative environment for scientists and engineers to engage and work with industry to produce studies, prototypes and systems linked to the overall scientific success of the SKA, MWA and ASKAP.

    MORE INFORMATION

    The MWA
    The Murchison Widefield Array (MWA) is a low frequency radio telescope and is the first of four Square Kilometre Array (SKA) precursors to be completed.
    A consortium of partner institutions from seven countries (Australia, USA, India, New Zealand, Canada, Japan, and China) financed the development, construction, commissioning, and operations of the facility. The MWA consortium is led by Curtin University.

    Parkes Observatory
    Parkes Observatory, just outside the central-west NSW town of Parkes, hosts the 64-metre Parkes radio telescope, one of the telescopes comprising CSIRO’s Australia Telescope National Facility.
    ICRAR
    The International Centre for Radio Astronomy Research (ICRAR) is a joint venture between Curtin University and The University of Western Australia with support and funding from the State Government of Western Australia.

    CASS
    CSIRO Astronomy and Space Science (CASS) operates the Australia Telescope National Facility (ATNF), comprising a set of world-class radio-astronomy observatories including the Parkes 64-metre radio telescope and the Australia Telescope Compact Array (ATCA) in New South Wales, and the Australian Square Kilometre Array Pathfinder (ASKAP) in Western Australia.

    CSIRO ATCA at the Paul Wild Observatory, about 25 km west of the town of Narrabri in rural NSW about 500 km north-west of Sydney, AU

    SKA/ASKAP radio telescope at the Murchison Radio-astronomy Observatory (MRO) in Mid West region of Western Australia

     
  • richardmitnick 9:57 am on July 23, 2017 Permalink | Reply
    Tags: , , , , Hunting Molecules with the MWA, ICRAR, , The mercapto radical (SH) and nitric oxide (NO)   

    From ICRAR: “Hunting Molecules with the MWA” 

    ICRAR Logo
    International Centre for Radio Astronomy Research

    July 21, 2017

    Astronomers have used an Australian radio telescope to observe molecular signatures from stars, gas and dust in our galaxy, which could lead to the detection of complex molecules that are precursors to life.

    Using the Murchison Widefield Array (MWA), a radio telescope located in the Murchison region of Western Australia, the team successfully detected two molecules called the mercapto radical (SH) and nitric oxide (NO).

    1
    This image shows the centre of the Milky Way as seen by the Galactic Centre Molecular Line Survey. Credit: Chenoa Tremblay (ICRAR-Curtin)

    “The molecular transitions we saw are from slow variable stars—stars at the end of their lives that are becoming unstable,” said Chenoa Tremblay from the International Centre for Radio Astronomy Research (ICRAR) and Curtin University.

    “One of the unique aspects of this survey is that until now, no one has ever reported detections of molecules within the 70-300MHz frequency range of the MWA and this is the widest field-of-view molecular survey of the Milky Way ever published.”

    Since the 1980s, frequencies greater than 80GHz have been used for this type of work due to the freedom from radio frequency interference emitted by our mobile phones, televisions and orbiting satellites. But the extreme “radio quietness” of the Murchison Radio-astronomy Observatory, where the telescope is located, allows astronomers to study molecular signatures from stars and star-forming regions at lower frequencies.

    “Before this study, the mercapto radical had only been seen twice before at infrared wavelengths, in a different part of the electromagnetic spectrum,” said Dr Maria Cunningham from the University of New South Wales.

    “This shows that molecules are emitting photons detectable around 100MHz and we can detect these molecular signatures using the MWA—it’s very exciting for us,” she said.

    Following on from the pilot study, a survey of the Orion region is now in progress, again using the MWA, in the frequency range of 99-270MHz. The Orion nebula is a chemical-rich environment and one of the closest star-forming regions to Earth. The aim is to detect more chemical tracers in stars, compare these regions to the observations from the Galactic Centre pilot region and to better understand the emission mechanisms of these molecules.

    “This new technique paves the way for deeper surveys that can probe the Milky Way and other galaxies in search of molecular precursors to life,” said Tremblay.

    PUBLICATION DETAILS

    A First Look for Molecules between 103 and 133MHz using the Murchison Wideeld Array, published in the Monthly Notices of the Royal Astronomical Society on July 21, 2017.

    See the full article here .

    Please help promote STEM in your local schools.
    STEM Icon

    Stem Education Coalition

    ICRAR is an equal joint venture between Curtin University and The University of Western Australia with funding support from the State Government of Western Australia. The Centre’s headquarters are located at UWA, with research nodes at both UWA and the Curtin Institute for Radio Astronomy (CIRA).
    ICRAR has strong support from the government of Australia and is working closely with industry and the astronomy community, including CSIRO and the Australian Telescope National Facility, iVEC, and the international SKA Project Office (SPO), based in the UK.

    ICRAR is:

    Playing a key role in the international Square Kilometre Array (SKA) project, the world’s biggest ground-based telescope array.


    Attracting some of the world’s leading researchers in radio astronomy, who will also contribute to national and international scientific and technical programs for SKA and ASKAP.
    Creating a collaborative environment for scientists and engineers to engage and work with industry to produce studies, prototypes and systems linked to the overall scientific success of the SKA, MWA and ASKAP.

    Murchison Widefield Array,SKA Murchison Widefield Array, Boolardy station in outback Western Australia, at the Murchison Radio-astronomy Observatory (MRO)


    A Small part of the Murchison Widefield Array

    Enhancing Australia’s position in the international SKA program by contributing to the development process for the SKA in scientific, technological and operational areas.
    Promoting scientific, technical, commercial and educational opportunities through public outreach, educational material, training students and collaborative developments with national and international educational organisations.
    Establishing and maintaining a pool of emerging and top-level scientists and technologists in the disciplines related to radio astronomy through appointments and training.
    Making world-class contributions to SKA science, with emphasis on the signature science themes associated with surveys for neutral hydrogen and variable (transient) radio sources.
    Making world-class contributions to SKA capability with respect to developments in the areas of Data Intensive Science and support for the Murchison Radio-astronomy Observatory.

     
  • richardmitnick 2:11 pm on March 28, 2017 Permalink | Reply
    Tags: , , , , ICRAR, ,   

    From ICRAR: “Astronomers probe swirling particles in halo of starburst galaxy’ 

    ICRAR Logo
    International Centre for Radio Astronomy Research

    March 28, 2017

    1
    NGC253 starburst galaxy in optical (green; SINGG Survey) and radio (red; GLEAM) wavelengths. The H-alpha line emission, which indicates regions of active star formation, is highlighted in blue (SINGG Survey; Meurer+2006). Credits: A.D. Kapinska, G. Meurer. ICRAR/UWA/CAASTRO.

    Astronomers have used a radio telescope in outback Western Australia to see the halo of a nearby starburst galaxy in unprecedented detail.

    A starburst galaxy is a galaxy experiencing a period of intense star formation and this one, known as NGC 253 or the Sculptor Galaxy, is approximately 11.5 million light-years from Earth.

    “The Sculptor Galaxy is currently forming stars at a rate of five solar masses each year, which is a many times faster than our own Milky Way,” said lead researcher Dr Anna Kapinska, from The University of Western Australia and the International Centre for Radio Astronomy Research (ICRAR) in Perth.

    The Sculptor Galaxy has an enormous halo of gas, dust and stars, which had not been observed before at frequencies below 300 MHz. The halo originates from galactic “fountains” caused by star formation in the disk and a super-wind coming from the galaxy’s core.

    The study used data from the ‘GaLactic and Extragalactic All-sky MWA’, or ‘GLEAM’ survey, which was observed by the Murchison Widefield Array (MWA) radio telescope located in remote Western Australia.

    2
    Murchison Widefield Array (MWA) radio telescope

    “With the GLEAM survey we were able, for the first time, to see this galaxy in its full glory with unprecedented sensitivity at low radio frequencies,” said Dr Kapinska.

    “We could see radio emission from electrons accelerated by supernova explosions spiralling in magnetic fields, and absorption by dense electron-ion plasma clouds —it’s absolutely fascinating.”

    The MWA is a precursor to the Square Kilometre Array (SKA) radio telescope, part of which will be built in Western Australia in the next decade.

    Co-author Professor Lister Staveley-Smith, from ICRAR and the ARC Centre of Excellence for All-sky Astrophysics (CAASTRO), said the SKA will be the largest radio telescope in the world and will be capable of discovering many new star-forming galaxies when it comes online.

    “But before we’re ready to conduct a large-scale survey of star-forming and starburst galaxies with the SKA we need to know as much as possible about these galaxies and what triggers their extreme rate of star formation,” he said.

    PUBLICATION DETAILS

    Spectral Energy Distribution and Radio Halo of NGC 253 at Low Radio Frequencies, published in the Astrophysical Journal on March 28th, 2017.

    See the full article here .

    Please help promote STEM in your local schools.
    STEM Icon

    Stem Education Coalition

    ICRAR is an equal joint venture between Curtin University and The University of Western Australia with funding support from the State Government of Western Australia. The Centre’s headquarters are located at UWA, with research nodes at both UWA and the Curtin Institute for Radio Astronomy (CIRA).
    ICRAR has strong support from the government of Australia and is working closely with industry and the astronomy community, including CSIRO and the Australian Telescope National Facility, iVEC, and the international SKA Project Office (SPO), based in the UK.

    ICRAR is:

    Playing a key role in the international Square Kilometre Array (SKA) project, the world’s biggest ground-based telescope array.

    SKA Square Kilometer Array
    Attracting some of the world’s leading researchers in radio astronomy, who will also contribute to national and international scientific and technical programs for SKA and ASKAP.
    Creating a collaborative environment for scientists and engineers to engage and work with industry to produce studies, prototypes and systems linked to the overall scientific success of the SKA, MWA and ASKAP.

    SKA Murchison Widefield Array
    A Small part of the Murchison Widefield Array

    Enhancing Australia’s position in the international SKA program by contributing to the development process for the SKA in scientific, technological and operational areas.
    Promoting scientific, technical, commercial and educational opportunities through public outreach, educational material, training students and collaborative developments with national and international educational organisations.
    Establishing and maintaining a pool of emerging and top-level scientists and technologists in the disciplines related to radio astronomy through appointments and training.
    Making world-class contributions to SKA science, with emphasis on the signature science themes associated with surveys for neutral hydrogen and variable (transient) radio sources.
    Making world-class contributions to SKA capability with respect to developments in the areas of Data Intensive Science and support for the Murchison Radio-astronomy Observatory.

     
  • richardmitnick 8:34 am on March 7, 2017 Permalink | Reply
    Tags: , , , ICRAR, Star clusters discovery could upset the astronomical applecart, Star clusters in the Large Magellanic Cloud   

    From ICRAR: “Star clusters discovery could upset the astronomical applecart” 

    ICRAR Logo
    International Centre for Radio Astronomy Research

    March 7, 2017
    Dr Bi-Qing For (ICRAR-UWA)
    biqing.for@icrar.org
    +61 8 6488 7729

    Dr Kenji Bekki (ICRAR-UWA)
    kenji.bekki@icrar.org
    +61 8 6488 7730

    Pete Wheeler—Media Contact, ICRAR
    pete.wheeler@icrar.org
    +61 423 982 018

    1
    This image from NASA’s Spitzer Space Telescope features the Large Magellanic Cloud, a satellite galaxy to our own Milky Way galaxy. Overlaying the image are circles showing the locations of 15 star clusters where multiple generations of stars have been discovered. Credit: Karl Gordon and Margaret Meixner – Space Telescope Science Institute/AURA/NASA. Compilation by Bi-Qing For and Kenji Bekki (ICRAR/UWA).

    The discovery of young stars in old star clusters could send scientists back to the drawing board for one of the Universe’s most common objects.

    Dr Bi-Qing For, from the International Centre for Radio Astronomy Research in Perth, said our understanding of how stars evolve is a cornerstone of astronomical science.

    “There are a billion trillion stars in the Universe and we’ve been observing and classifying those we can see for more than a century,” she said.

    “Our models of stellar evolution are based on the assumption that stars within star clusters formed from the same material at roughly the same time.”

    A star cluster is a group of stars that share a common origin and are held together by gravity for some length of time.

    Because star clusters are assumed to contain stars of similar age and composition researchers have used them as an “astronomical laboratory” to understand how mass affects the evolution of stars.

    “If this assumption turns out to be incorrect, as our findings suggest, then these important models will need to be revisited and revised,” Dr For said.

    The discovery, published today in the Monthly Notices of the Royal Astronomical Society, involves a study of star clusters located in the Large Magellanic Cloud, a neighbouring galaxy to the Milky Way.

    By cross-matching the locations of several thousand young stars with the locations of stellar clusters, the researchers found 15 stellar candidates that were much younger than other stars within the same cluster.

    “The formation of these younger stars could have been fuelled by gas entering the clusters from interstellar space,” said co-author Dr Kenji Bekki, also from the International Centre for Radio Astronomy Research.

    “But we eliminated this possibility using observations made by radio telescopes to show that there was no correlation between interstellar hydrogen gas and the location of the clusters we were studying.

    “We believe the younger stars have actually been created out of the matter ejected from older stars as they die, which would mean we have discovered multiple generations of stars belonging to the same cluster.”

    Dr Bekki said the stars were currently too faint to see using optical telescopes because of the dust that surrounds them.

    “They have been observed using infrared wavelengths by orbiting space telescopes Spitzer and Herschel, operated by NASA and the European Space Agency,” he said.

    “An envelope of gas and dust surrounds these young stars but as they become more massive and this shroud blows away, they will become visible at optical wavelengths for powerful instruments like the Hubble Space Telescope.”

    “If we point Hubble at the clusters we’ve been studying, we should be able to see both young and old stars and confirm once and for all that star clusters can contain several generations of stars.”

    See the full article here .

    Please help promote STEM in your local schools.
    STEM Icon

    Stem Education Coalition

    ICRAR is an equal joint venture between Curtin University and The University of Western Australia with funding support from the State Government of Western Australia. The Centre’s headquarters are located at UWA, with research nodes at both UWA and the Curtin Institute for Radio Astronomy (CIRA).
    ICRAR has strong support from the government of Australia and is working closely with industry and the astronomy community, including CSIRO and the Australian Telescope National Facility, iVEC, and the international SKA Project Office (SPO), based in the UK.

    ICRAR is:

    Playing a key role in the international Square Kilometre Array (SKA) project, the world’s biggest ground-based telescope array.

    SKA Square Kilometer Array
    Attracting some of the world’s leading researchers in radio astronomy, who will also contribute to national and international scientific and technical programs for SKA and ASKAP.
    Creating a collaborative environment for scientists and engineers to engage and work with industry to produce studies, prototypes and systems linked to the overall scientific success of the SKA, MWA and ASKAP.

    SKA Murchison Widefield Array
    A Small part of the Murchison Widefield Array

    Enhancing Australia’s position in the international SKA program by contributing to the development process for the SKA in scientific, technological and operational areas.
    Promoting scientific, technical, commercial and educational opportunities through public outreach, educational material, training students and collaborative developments with national and international educational organisations.
    Establishing and maintaining a pool of emerging and top-level scientists and technologists in the disciplines related to radio astronomy through appointments and training.
    Making world-class contributions to SKA science, with emphasis on the signature science themes associated with surveys for neutral hydrogen and variable (transient) radio sources.
    Making world-class contributions to SKA capability with respect to developments in the areas of Data Intensive Science and support for the Murchison Radio-astronomy Observatory.

     
  • richardmitnick 2:44 pm on February 25, 2017 Permalink | Reply
    Tags: , , , ICRAR, , , , SKA South Africa   

    From CSIRO via AFR: “The Square Kilometre Array: going to infinity and beyond” 

    CSIRO bloc

    Commonwealth Scientific and Industrial Research Organisation

    2

    The Australian Financial Review

    Feb 24 2017
    Tess Ingram

    1
    In the red dust of WA, telescopes are already tuning in to the faint signals from the very edge of the universe. TREVOR COLLENS

    Thunderstorms are common in the Murchison region of Western Australia in January but for Luke Horsley the 21 millimetres of rain that drilled into the red dirt overnight are problematic.

    It is 6am in an old stone cottage at Boolardy Station. Horsley grabs the receiver of a black landline telephone and tells a colleague 330 kilometres away in Geraldton not to make the bumpy four-hour drive from the coast. The roads might be closed.

    The landline, which would look commonplace in any city office, stands out at Boolardy. Horsley may be working as an engineering support technician at a $400 million high-tech facility but using a mobile phone or even a humble Wi-Fi network is not an option. The radio waves they produce would obliterate the science he is working on – radio astronomy.

    Horsley and his colleagues are here in the middle of nowhere working on the world’s largest science project – the Square Kilometre Array (SKA).

    SKA Square Kilometer Array

    A multibillion-dollar endeavour first dreamt up in 1991, the SKA is in essence a vast radio telescope that will literally look back through time to the dawn of the universe. To call its mission ambitious is to redefine understatement – the SKA aims to resolve some of the most profound unanswered questions of our time. Was Einstein right about gravity? When did the first stars, galaxies and black holes form? What is dark energy? And, quite possibly, are we alone in the universe?

    3
    A racehorse goanna explores one of the tiles in the Murchison Widefield Array. Trevor Collens

    To achieve this ten countries have joined forces to build the SKA – a telescope so large it will eventually have a collecting area of more than a million square metres. Australia won the right to host part of the project in 2012 after a hotly contested 8-year bidding process conducted by the SKA Organisation, the not-for profit dedicated to overseeing its design, construction and operation.

    South Africa will share the prize, ultimately hosting 2000 dishes probing the universe as far as six billion light years away. And here in the red dust of the Murchison a million individual antennas, each resembling a Christmas tree, will eventually tune in to the faint signals from the very edge of the universe – “light” emitted by events more than 13 billion years ago.

    SKA Murchison Widefield Array,SKA Murchison Widefield Array, Boolardy station in outback Western Australia, at the Murchison Radio-astronomy Observatory (MRO)
    SKA Murchison Widefield Array,SKA Murchison Widefield Array, Boolardy station in outback Western Australia, at the Murchison Radio-astronomy Observatory (MRO)

    Before the storm

    It is the day before the thunderstorm and here in the low-lying mulga scrub even the racehorse goanna look like they’re over the 38-degree temperatures and enervating humidity. Until a few years ago Boolardy was a cattle station and my visit coincides with that of the former manager and his daughter, here to round up the last escapee livestock.

    The Murchison shire, which is roughly the size of Denmark, is an ideal site for radio telescopes. It is so isolated it describes itself as “the shire with no town” – and claims to be the only one in Australia. During the SKA bidding process the Australian government protected it with a 260-kilometre “radio quiet zone”. Given the 50,000-square-kilometre area is home to just 113 people – most in the local Pia Wadjarri Indigenous community as well as a few remaining station owners – the chances of unwanted radio activity are slim.

    4
    Dr Balthasar Indermühle and Brett Hiscock in front of some of CSIRO’s 36 ASKAP radio telescope dishes in the Murchison scrub. TREVOR COLLENS

    Still, visitors aren’t encouraged. An “emergency flipchart” on the wall of a site office has instructions for dealing with an “unaccounted visitor” alongside “fire and explosions” and a “bomb threat response”. Disrupt the science at your peril.

    In the airvconditioned comfort of a control building buffered by two double-door “airlocks”, CSIRO experimental scientist Dr Balthasar Indermühle is working on a radio-frequency interference (RFI) monitoring system he is building. The Swiss-born scientist is here from his home in Sydney and his job is to keep the two radio telescopes that currently occupy the Murchison Radio-astronomy Observatory (MRO) as clean of radio interference as possible.

    Indermühle was an airline pilot in Switzerland. Flying through the sky at night is about as close as you can get to space travel without leaving the planet and from his vantage point in the cockpit, he would regularly contemplate the universe. After exchanging airplanes for software development and founding a company called Inside Systems, Indermühle was drawn back to the night sky. Having already tinkered away at a Masters in astronomy online, he left for Australia to undertake a PhD in astrophysics at the University of New South Wales.

    Indermühle’s main interest lies in making this pursuit as easy as possible by minimising the amount of “earth noise” the radio telescopes pick up. This is no easy feat. To detect such weak radio signals from space, the telescopes need to be ultra-sensitive.

    5
    The MRO is at the centre of a 500km wide radio quiet zone where no mobile phones are allowed. TREVOR COLLENS

    “The entire energy that has been received by all the radio telescopes on the planet since the beginning of radio astronomy, the energy equivalent of that is ash from a cigarette dropping one centimetre in height,” Dr Indermühle explains as we circle one of the dishes hard at work.

    “That is how sensitive our equipment is. We could see a mobile phone that is a light year away.” A mobile phone on the moon heard via these telescopes would be booming, let alone one at Boolardy.

    Indermühle is one of a small crew of engineers and scientists, from the CSIRO and The International Centre for Radio Astronomy Research (ICRAR), who are pushing the frontiers of astronomical science at the MRO, which will host the SKA and is already home to the MWA and ASKAP telescopes.

    SKA/ASKAP radio telescope at the Murchison Radio-astronomy Observatory (MRO) in Mid West region of Western Australia
    SKA/ASKAP radio telescope at the Murchison Radio-astronomy Observatory (MRO) in Mid West region of Western Australia

    Horsley, his ICRAR colleague Mia Walker and Dutch intern Ric Budē are braving the heat at the MWA to undertake repairs and prepare for the rollout of an expansion. The remainder of their team, former firefighter Dave Emrich and intern Kim Steele, who was part of a “student army” that helped build the array and is now working on the project full time, are in the MRO’s control building working on the spaghetti strands of cables that feed the data from the MWA into a complex computing system. Steele’s own journey is about to take a new turn when she jets off to Finland to undertake her PhD.

    6
    Former firefighter Dave Emrich says “when you look up at the sky at night and see all the stars; it makes you think”. Trevor Collens

    Everywhere else is dead quiet.

    Dark stuff

    If a mechanic told you he only understood about 5 per cent of your car, you wouldn’t be filled with confidence. Unfortunately, this is the awkward situation astronomers are in.

    “Astronomers are incredibly ignorant of the universe we live in,” explains ICRAR executive director Peter Quinn, an astrophysicist who once worked on the Hubble Telescope with NASA. “There’s about 95 per cent or more of it that’s been called ‘dark’.” Roughly 25 per cent of that is considered dark matter and 70 per cent dark energy. Scientists have little idea what they are.

    Quinn heads up ICRAR in Perth, a research facility set up specifically to help interpret data from the Murchison telescopes and run jointly by Curtin University and the University of Western Australia. It is part-funded by the WA government. Like so many of the others I meet while researching the SKA, Quinn’s journey into the deep space world has – much like the project itself – had unlikely stops and starts but never been short of interesting.

    Quinn began at the University of Wollongong and moved on to the prestigious California Institute of Technology before joining the Hubble institute at NASA’s Space Telescope Science Institute in Baltimore. He returned to Australian National University to lead a global search for dark matter. His work did indeed find early evidence of dark matter and in 1991 graced the cover of Nature. From there Quinn went to the European Southern Observatory headquarters in Munich and ultimately to ICRAR. He has spent the bulk of this career trying to crack the “dark” mystery.

    “I wanted to understand why all these galaxies looked like they looked,” Quinn tells me. “Why are some round and some flat and some green and some blue? When you start down that path, you all of a sudden realise what you’re looking at is just the frosting on the cake.

    “What the universe really made is all this black stuff which sits underneath. This dark stuff is driving everything, its presence, its shape, its physics. If you want to understand galaxies, you have to understand this dark stuff.

    “That’s probably the biggest, in my mind, unsolved mystery in the universe.”

    He is hopeful the SKA might provide an end to the “frustrating search” during his lifetime. Resolving this mystery is one of the five core science drivers of the project.

    A movie of the deep past

    7
    Murchison Widefield Array Project Manager Randall Wayth switched from computers to space. TREVOR COLLENS

    After the Big Bang, which is thought to have occurred about 13.7 billion years ago, the universe was transformed from an expanding ball of hot particles into a cool sea of gas, predominantly hydrogen. This is thought to have occurred over about 380,000 years.

    Inflation to gravitational waves derived from ESA/Planck and the DOE NASA NSF interagency task force on CMB research, Bock et al. (2006, astro-ph/0604101); modifications by E. Siegel.
    Inflation to gravitational waves derived from ESA/Planck and the DOE NASA NSF interagency task force on CMB research, Bock et al.

    There was no light during this time, aptly known as the Dark Ages, so no optical telescope has ever been able to observe this phase of the universe’s evolution.

    At some point – probably about 400 million years after the Big Bang – there was the “cosmic dawn” when the first galaxies and stars are thought to have burst into existence.

    8
    Cosmic dawn. BBC

    But it took until about 1 billion years after the Big Bang for radiation from those stars and galaxies to clear the hydrogen “fog” and allow light to escape. That period of about 600 million years is known as the “Epoch of Reionisation” and it is one of the last frontiers in cosmology.

    11
    Epoch of Reionisation

    The MWA telescope is already working to define what happened.

    Trick of the light

    It may sound impossible to delineate something so massive but it works like this.

    Human eyes can only collect and focus a certain range of the electromagnetic spectrum – what we call visible light. But in order to understand the universe, we need to study astronomical objects over the broad range of wavelengths they emit – from the gamma rays emitted from emerging stars to the radio waves released from black holes.

    Radio waves are simply “invisible” light and astronomers have developed telescopes to pick up this light in wavelengths ranging from a fraction of a millimetre to metres long. The more sensitive the telescope, the clearer picture it can create of weaker signals. The older the signal, the weaker it is because it has stretched out as it has travelled – just like when you look at the sun, you are seeing it as it was 8.2 minutes ago because that is how long it takes sunlight to travel to Earth.

    Therefore, the most powerful radio telescopes are essentially time machines.

    FAST radio telescope located in the Dawodang depression in Pingtang county Guizhou Province, South China
    FAST radio telescope located in the Dawodang depression in Pingtang county Guizhou Province, South China, the world’s most powerful radio telescope

    ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres
    ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres, cureently the world’s most productive installation for millimeter and submillimeter astronomy

    9
    Dr Balthasar Indermühle’s main interest lies in minimising the amount of “earth noise” the radio telescopes pick up. Trevor Collens

    Time travel

    For scientists like MWA director Randall Wayth, time travel comes with its challenges.

    Wayth, a software consultant who followed his passion to become an astrophysicist, says the Epoch of Reionisation project is the most challenging project the telescope is seeking to complete.

    “It is really difficult because the signal we are looking for is about a million times fainter than all of the other stuff that’s in the sky,” he says.”This is like looking for a little torch next to a really big spotlight.”

    Wayth spent five years in software consulting before deciding to opt for “something a bit more meaningful” – a phD in astrophysics at the University of Melbourne. “It turns out that the whole radio astronomy side of things is an astonishingly good use of everything that you learnt in your engineering degree,” Wayth says. “And with modern radio astronomy as well it’s everything you learnt in your computer science degree because it’s all computers. No one actually goes and looks through an eyepiece anymore.”

    He returns to the Epoch of Reionisation.

    “We know about the very early universe. We know about today and halfway back in time,” he says. “Then there is this period that we almost know nothing about. That is what we’re trying to get to with the Epoch of Reionisation experiment.”

    At first glance the 2048 squat, spider-like antennas that constitute the MWA radio telescope are not at all impressive. But it is the MWA that has the honour of reaching back to the cosmic dawn and directly informing the design of the SKA’s future low-frequency antennas, which will be much more powerful. The MWA receives signals within the 80 to 300 megahertz bandwidth, the same low frequencies we typically broadcast FM radio and television signals on. It has been surveying the southern hemisphere since 2013.

    “The MWA would detect the Epoch of Reionisation and see things within it, but then the SKA would come along and see it in much greater resolution,” says Wayth.

    “We’re not sensitive enough to directly make images, which is kind of the holy grail, but SKA will be able to do that. What we can do is say, ‘yes, it happened over this time range and the kind of objects that are involved must have been X-ray emitting objects or small galaxies’ or whatever it was. So, we’ll be able to tie it down to some space and then SKA can go in.”

    So what has the MWA found in it’s three years of searching the southern skies? A big part of the answer is its GaLactic and Extragalactic All-sky MWA (GLEAM) survey. GLEAM produced a catalogue of 300,000 galaxies, picking up radio waves which, when translated into images, showed the sky in 20 primary colours – far better than the three humans can manage. With these images astronomers are already planning where to zoom in on when SKA comes online next year.

    Wayth and Emrich have similar backgrounds. Both studied electrical engineering, with Emrich tacking on computer systems and Wayth computer science. After years as a professional engineer and then bush firefighter, an opportunity came up for Emrich to apply his background to a persistent passion of his, astronomy.

    He can trace his fascination with space back to his grandparents who took him camping in Hyden, a small town about 300 kilometres south-east of Perth popular with tourists because of its large wave-shaped rock, when he was a child.

    “They used to take us out to Wave Rock and Hyden and things to look at the sky at night,” Emrich recalls. “I remember gramps rattling the tent at 3am when we were all asleep and saying ‘you have to have a look at this’ and all of us grumbling about how early it was.

    “I think there is something primitive about human beings that when you look up at the sky at night and see all the stars; it makes you think.”

    He has been involved in the MWA project since 2009 and says he has lost count of how many times he has travelled to the Murchison observatory, probably close to 100. His wife and three teenage children – who live in Perth – don’t mind the time away as much as they did when he was battling bushfires across Western Australia – at least these trips are planned in advance.

    8
    A “radio colour” view of the sky above a tile of the Murchison Widefield Array radio telescope.The Milky Way is visible as a band across the sky and the dots beyond are some of the 300,000 galaxies observed by the telescope for the GLEAM survey. Credit: Radio image by Natasha Hurley-Walker (ICRAR/Curtin) and the GLEAM Team. MWA tile and landscape by Dr John Goldsmith / Celestial Visions. Curtin/ICRAR/JohnGoldsmith

    Kelly’s input

    Patricia Kelly is as responsible as anyone for Australia being chosen to co-host the SKA. A career public servant whose early work included developing social policy, Kelly’s journey took a turn towards science when she she moved to the Industry department in 1995 and began working with the research sector and on innovation policy. In 2007 she became involved with the SKA bidding process through her role as deputy secretary responsible for the department’s science and research streams.

    As the big idea crystallised into action Kelly led a joint bid by Australia and New Zealand to host the entire project. She was in Amsterdam advocating Australia’s case in 2012 when the SKA Organisation decided to split the project between Australia and South Africa. There was, Kelly says, an element of politics in that call. “But I think in the end it has not been a bad outcome. It has made it a truly global project in a way I think it wouldn’t have been if it had gone one way or the other.”

    Today Kelly chairs the Australia-New Zealand SKA Co-ordination Committee (NZ remains involved despite missing out on hosting the science) and is Australia’s representative on the board of the international SKA Organisation, which includes members from Australia, Canada, China, India, Italy, New Zealand, South Africa, Sweden, the Netherlands and the United Kingdom and is co-ordinating the whole project.

    There’s a lot to do.

    Two-phase approach

    The SKA is to be constructed in two phases. The first phase, SKA1, will constitute about 10 per cent of the full array and is about three-quarters of the way through its final design phase.

    SKA1 will see about 200 dishes rolled out in South Africa’s Karoo, a lightly populated semi-desert region north of Cape Town, including 64 dishes known as “MeerKAT” that have been acting as a local precursor project. The dishes will cover the 350MHz to 14 gigahertz range of the spectrum.

    SKA South Africa Icon
    SKA South Africa

    9
    Solar panels will provide power for the Murchison Radio-astronomy Observatory. Until now it has relied on diesel-powered generators. Trevor Collens

    In Australia, about 130,000 low frequency antennas will be constructed to cover the 50 to 350MHz range. Although the MWA’s “spiders” have been informing their design, the SKA antennas more closely resemble Christmas trees. The cost of constructing SKA1 has been capped at €675 million, with operations expected to cost another €100 million a year.

    Phase two will see the collective array expand to more than its namesake square kilometre, with a total 2000 dishes in South Africa and other African countries, including Botswana, Ghana and Kenya, and a staggering one million Christmas tree antennas creating a forest above the Murchison scrub.

    It is undoubtedly a huge endeavour with a significant cost. But everyone AFR Weekend speaks with is confident there will be payoffs beyond understanding what happened a long time ago in a galaxy far, far away.

    Wi-Fi was the result of CSIRO radio astronomers seeking to detect tiny, exploding black holes. A scientist at CERN, the European Organisation for Nuclear Research, invented the World Wide Web in 1989 to meet the demand for information sharing between scientists. Hierarchical Segmentation software developed by NASA is now used in medical imaging. Surely the SKA will be no different.

    Kelly, who is also the director-general of IP Australia, says it is most likely the SKA’s spin-offs will be things we are not able to predict.

    “Certainly the amount of data the telescope will generate and how to handle that data will be something that will generate a great deal of information and learning,” Kelly says.

    “The technologies being developed in terms of sensors … will have much broader implication for a range of industries and there is also a real need for ways of powering this telescope in an affordable way, so there is also a lot of work being done on remote energy solutions that, of course, are very much in the national mix at the moment.”

    Hitting top gear

    10
    There are 36 ASKAP dishes dotted across the MRO. Designed and built by the CSIRO, the organisation hopes the pioneering technology will be used by the larger SKA array in South Africa. Trevor Collens

    January has been an exciting month for the CSIRO’s Antony Schinckel. The man responsible for the design, construction and commissioning of the $165 million ASKAP telescope has just seen it click into top gear after extensive testing. And already the results, and the way they are being processed, is encouraging.

    ASKAP, Australian Square Kilometre Array Pathfinder, is the more familiar looking telescope at Murchison. It consists of 36 large, white dish antennas that work together as a single instrument. Each one bears a local Wajarri name – including Bundarra (stars), Wilara (the Moon) and Jirdilungu (the Milky Way) – an honour also afforded to Schinckel himself.

    “My Wajarri name is Minga, which is the Wajarri word for ant,” he explains from his office in Sydney. “I am certainly quite honoured to be one of the few people that was given a name.”

    The ASKAP telescope is mapping space out to about 3 billion light years away, using neutral gas to reveal hundreds of thousands of galaxies. The project, expected to take five years, is creating mind-boggling amounts of data. Even operating well below its full capacity the antennas are now churning out 5.2 terabytes of data per second. That’s about 15 per cent of all the data bouncing around the internet on any given second.

    From the telescope, the data goes down an 800km fibre optic cable to the Pawsey Supercomputing Centre and into a new, near automatic data-processing system Schinckel and his team have developed.

    “It’s like a 24/7 prestige car manufacturing plant – the raw materials flow in at one end, you decide what type of car you want to roll off the production line, and therefore what parts you need, and let it go to work overnight. Next morning you get a brand new, never been seen before, high-performance car.”

    While the ASKAP will not be directly used in Australia’s end of the SKA (that job’s for the “Christmas trees”), it as an important demonstrator of a key technology the CSIRO has designed and is being considered for the SKA mid-range telescopes to be rolled out in South Africa.

    Called a phased array feed (PAF), the technology is essentially an advanced version of a traditional radio telescope receiver, which detects and amplifies radio waves. Traditionally receivers have only been able to take snapshots of small pieces of the sky at once but the PAFs, with 188 individual receivers positioned in a chequerboard, allow a dramatically wider field of view.

    Schinckel, who spent 17 years at high-profile observatories in Hawaii, says the CSIRO has already sold one PAF to the Max Planck Institute for Radio Astronomy in Germany and is building a second for the Jodrell Bank Observatory in England. The next step could be its use in other fields.

    “In many ways we don’t know enough to know what those other uses might be,” Schinckel says.

    “They might be in medical imaging, for example, in tomography. It might be in ground imaging from aeroplanes or satellites. It could be in communications in cities where you have extremely high density communications and there are limits that that imposes. We simply don’t know at this juncture.

    “When you typically look back about five or ten years after a telescope was built, and you look to see what was the really exciting science that came out of it, often only about 30 per cent of the science that’s come out of it was what you had predicted or planned right back at the start,” he says.

    The big challenge

    Making sure the SKA has the computing power and data processing systems to handle the deluge of data is the big challenge for ICRAR’s director of data intensive astronomy, Andreas Wicenec.

    Phase one of the SKA alone will produce five times 2015’s global internet traffic. The data collected in a single day would take nearly two million years to play back on an iPod and will require the power of computer processing systems around ten times the size of today’s biggest machines.

    “This is a very important part of the project because this is the limiting factor essentially,” ICRAR’s Quinn says. “Unless they can manage the data, then the telescope doesn’t work.”

    The challenge of ensuring the SKA can process this unprecedented volume of data in near real-time is being tackled by institutes and companies across the globe, including tech powerhouses Amazon, Intel, IBM and Cisco Systems which are all providing input into how the systems should function.

    The brain – data flow

    From Perth, Wicenec is sharing valuable insights with the SKA design teams from the data journey of the spidery-MWA. He is also taking a leading role in designing the “brain” of the SKA – the science data processor.

    After a correlator on site at the MRO has conducted a first filter of the mass of data, reducing it in size, it will travel down the fibre optic cable to Perth’s Pawsey Supercomputing Centre.

    12
    SKA correlator

    Here the “brain” extracts unwanted radio noise, from an errant mobile phone or the odd aircraft that flies overhead, and turns the data into something scientists can use, such as an image which can then be distributed to scientists across the globe,

    In terms of data flow, the MWA is a factor of 20 larger than the last project Wicenec worked on, the Atacama Large Millimeter Array in Chile, an ambitious array perched atop a plateau more than 5000 metres above sea level.

    “That’s already a big step but what we are talking from MWA to SKA is actually a factor of 1800 in terms of data flow,” Wicenec says, explaining the SKA’s jump in scale also delivers an increase in resolution, compounding the data deluge.

    And if that wasn’t hard enough, scientists from across the globe, ranging from the Onsala Space Observatory in Sweden to the National Centre for Radio Astrophysics of India, need the data to be sent out again.

    “We are actually sending about three to four times more data out [from the MWA] than what we are receiving, so that means about a good gigabyte or 1.2 gigabytes a second out to people every single day,” Wicenec says.

    Managing the project

    If you think managing tradies on your home renovation is tough, spare a thought for David Luchetti. As general manager of the Australian SKA Office, he heads the agency responsible for co-ordinating Australia’s commitment to the project – everything from federal funding to site access – and has unrivalled knowledge on its progress. For a public sector veteran who took on the role with little understanding of astronomy, building knowledge of the science has been a learning curve.

    “Even now, after my eight years [in the role], it makes you realise that there’s some seriously smart people out there,” Luchetti laughs. “There’s been a certain process of osmosis, I think, in actually absorbing some of the collective wisdom of the people.”

    He says the biggest challenge in a role co-ordinating a highly complex, multibillion-dollar project has been to keep momentum going on its many and varied streams of work. There’s finalising the design, securing funding, signing the Indigenous Land Use agreement and liaising with the WA government.

    “It’s not a sequential project, in the sense that once you do ‘A’ then you move on to ‘B’,” he says. “Keeping all of them moving at the same time is probably the main challenge.”

    Luchetti says the global effort is like a duck, “it’s quite serene on top but there is a lot happening below the surface”. He has also been responsible for translating “scientist” into “politician”. A key hurdle for sciences such as astronomy is to translate researchers’ excitement about the unknown into funding. The idea of “we will find something or there will be a spin-off but we can’t tell you what it will be” does not sell easily.

    The Australian government has understood the vision, contributing about $400 million to SKA-related activities to date, with the West Australian government spending about a further $111 million on radio astronomy, most linked to the SKA. Premier Colin Barnett says the SKA could add more than $100 million to the state’s economy over the next 20 years through locally supplied goods and services. And managing all those terabytes of data would bring valuable experience to WA.

    Alien life

    But what about the aliens? The first thing that comes to many peoples’ minds when they think about what else could be out there is aliens. Is there other intelligent life? SKA could provide an answer.

    The man heading the entire SKA project, Phil Diamond, director general of the SKA Organisation.

    “The public think that [looking for aliens] is what we do,” Diamond says. “It is not actually what radio astronomers do. However, SKA will be the most capable machine that human kind has ever developed to hunt for that signal from intelligent extraterrestrial civilisations.

    “We do have people within our science working groups who are focused purely on that aspect but it is definitely not the main stream of what we do.

    “However if we detect the signal, I think the interest will rise enormously.”

    Enormously is an understatement. If an artificial signal which suggests intelligent life, for example a distant airport, is detected by the SKA, another radio telescope would be used to verify the signal. And then, Diamond explains there is actually an astronomical protocol for how it should be dealt with.

    “There is no way it could remain secret because with the prevalence of social media these days, it gets out,” he says. “It would be global news within 24 hours.”

    For Diamond, a 35-year radio astronomer, his key interest is not in the extraterrestrial but rather how our own galaxy has evolved.

    “I am quite interested in the theme we have dubbed ‘the cradle of life’ which will look at how planets form and evolve, detecting the molecular signals of amino acids and things like that in space,” he says.

    Two key focuses

    But before the science, Diamond has a big job on his hands.

    “We are dealing with more than 600 scientists and engineers in more than 10 countries… people in almost every time zone you can imagine from New Zealand to Western Canada and all the cultural and language differences that go with that,” Diamond says.

    “Pulling all of that together has been one of the biggest challenges. I do say to my staff here that the communications in this project will be perfect the day we switch the telescope off,” which is expected to be about 50 years after it fires up.

    The SKA Organisation has two key focuses at the moment – signing off on a final design and inking a binding SKA treaty between the 10 member countries, committing them to funding and contracts for the commencement of construction, targeted for late-2018.

    But even Diamond admits hitting that construction target will be a tough ask.

    “That is going to be very tight,” he says. “There are multiple things that have to happen before we can start construction. On the design side we have to deliver a design that has been validated and is ready to go out to industry for tender. On the other side the governments have to deliver a convention, the governance structure and the legal organisation that enables us to receive money from the governments and go out and pay industry.

    “These things have to converge on the right time scale. So far everything is pointing in the direction that will happen … but it is very tight.”

    Diamond can control the design process but the speed of the governments is out of his hands. For example, all of the Brexit legislation that has to go through the British government could slow the nation ratifying its end of the treaty.

    As it reaches the end of the design process, the SKA Organisation is also re-examining its €675 million cost target for the construction of SKA1.

    “Like all major scientific projects like this, our cost estimates are coming in a little higher than we had hoped,” Diamond says. About 30 per cent to be exact.

    “So we are looking at if there is any reuse of technologies and software from the precursors that can help us reduce the costs. This is a normal project process, it is nothing out of the ordinary.”

    While all of that is a long way from the MWA team assembling more spidery antennas in the scorching heat of the Murchison, there is a palpable excitement that their telescope could now play an even bigger role in the world’s largest science project.

    As they make the 40km drive back to Boolardy from the MRO, lightning flashes overhead. Everyone is praying the storm doesn’t target its science – last year it claimed thousands of dollars worth of antennas atop CSIRO’s radio interference tower.

    The night passes and while the lightning has not been an issue, the rain has. Horsley was right to be worried, all but one of the roads has been closed. And the forecast for tomorrow is no better.

    The ICRAR team cuts their site trip three days short and piles into the back of rented four-wheel drives, dodging lizards and kangaroos on their way back to Geraldton.

    The radio waves are from 13 billion years ago, they can wait another month.

    The reporter travelled to the MRO courtesy of ICRAR.

    See the full article here .

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    CSIRO campus

    CSIRO, the Commonwealth Scientific and Industrial Research Organisation, is Australia’s national science agency and one of the largest and most diverse research agencies in the world.

     
    • richardmitnick 10:59 pm on February 25, 2017 Permalink | Reply

      The sciencesprings blog is shown on Twitter. The Twitter feed for this post resulted in 63 retweets.
      I am thrilled.

      Like

  • richardmitnick 3:11 pm on January 18, 2017 Permalink | Reply
    Tags: , , , , , Galaxy Murder Mystery, ICRAR,   

    From ICRAR: “Galaxy Murder Mystery” 

    ICRAR Logo
    International Centre for Radio Astronomy Research

    January 17, 2017
    Mr Toby Brown (ICRAR-UWA, Swinburne University of Technology)
    E: toby.brown@icrar.org
    M: +61 6488 7753

    Dr Barbara Catinella (ICRAR-UWA)
    E: barbara.catinella@icrar.org
    Tel: +972 89346511

    Pete Wheeler—Media Contact, ICRAR
    E: pete.wheeler@icrar.org
    M: +61 423 982 018

    1
    This artist’s impression shows the spiral galaxy NGC 4921 based on observations made by the Hubble Space Telescope. Credit: ICRAR, NASA, ESA, the Hubble Heritage Team (STScI/AURA)

    It’s the big astrophysical whodunnit. Across the Universe, galaxies are being killed and the question scientists want answered is, what’s killing them?

    New research published today by a global team of researchers, based at the International Centre for Radio Astronomy Research (ICRAR), seeks to answer that question. The study reveals that a phenomenon called ram-pressure stripping is more prevalent than previously thought, driving gas from galaxies and sending them to an early death by depriving them of the material to make new stars.

    The study of 11,000 galaxies shows their gas—the lifeblood for star formation—is being violently stripped away on a widespread scale throughout the local Universe.

    Toby Brown, leader of the study and PhD candidate at ICRAR and Swinburne University of Technology, said the image we paint as astronomers is that galaxies are embedded in clouds of dark matter that we call dark matter halos.

    Dark matter is the mysterious material that despite being invisible accounts for roughly 27 per cent of our Universe, while ordinary matter makes up just 5 per cent. The remaining 68 per cent is dark energy.

    “During their lifetimes, galaxies can inhabit halos of different sizes, ranging from masses typical of our own Milky Way to halos thousands of times more massive,” Mr Brown said.

    “As galaxies fall through these larger halos, the superheated intergalactic plasma between them removes their gas in a fast-acting process called ram-pressure stripping.

    “You can think of it like a giant cosmic broom that comes through and physically sweeps the gas from the galaxies.”

    Mr Brown said removing the gas from galaxies leaves them unable to form new stars.

    “It dictates the life of the galaxy because the existing stars will cool off and grow old,” he said.

    “If you remove the fuel for star formation then you effectively kill the galaxy and turn it into a dead object.”

    ICRAR researcher Dr Barbara Catinella, co-author of the study, said astronomers already knew ram-pressure stripping affected galaxies in clusters, which are the most massive halos found in the Universe.

    “This paper demonstrates that the same process is operating in much smaller groups of just a few galaxies together with much less dark matter,” said Mr. Brown. “Most galaxies in the Universe live in these groups of between two and a hundred galaxies,” he said.

    “We’ve found this removal of gas by stripping is potentially the dominant way galaxies are quenched by their surrounds, meaning their gas is removed and star formation shuts down.”

    The study was published in the journal Monthly Notices of the Royal Astronomical Society. It used an innovative technique combining the largest optical galaxy survey ever completed—the Sloan Digital Sky Survey—with the largest set of radio observations for atomic gas in galaxies —the Arecibo Legacy Fast ALFA survey.

    SDSS Telescope at Apache Point, NM, USA
    SDSS Telescope at Apache Point, NM, USA
    Universe map Sloan Digital Sky Survey (SDSS) 2dF Galaxy Redshift Survey
    Universe map Sloan Digital Sky Survey (SDSS) 2dF Galaxy Redshift Survey

    NAIC/Arecibo Observatory, Puerto Rico, USA
    NAIC/Arecibo Observatory, Puerto Rico, USA
    3
    The Arecibo Legacy Fast ALFA Survey

    Mr Brown said the other main process by which galaxies run out of gas and die is known as strangulation.

    “Strangulation occurs when the gas is consumed to make stars faster than it’s being replenished, so the galaxy starves to death,” he said.

    “It’s a slow-acting process. On the contrary, what ram-pressure stripping does is bop the galaxy on the head and remove its gas very quickly—of the order of tens of millions of years—and astronomically speaking that’s very fast.”

    See the full article here .

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    ICRAR is an equal joint venture between Curtin University and The University of Western Australia with funding support from the State Government of Western Australia. The Centre’s headquarters are located at UWA, with research nodes at both UWA and the Curtin Institute for Radio Astronomy (CIRA).
    ICRAR has strong support from the government of Australia and is working closely with industry and the astronomy community, including CSIRO and the Australian Telescope National Facility, iVEC, and the international SKA Project Office (SPO), based in the UK.

    ICRAR is:

    Playing a key role in the international Square Kilometre Array (SKA) project, the world’s biggest ground-based telescope array.

    SKA Square Kilometer Array
    Attracting some of the world’s leading researchers in radio astronomy, who will also contribute to national and international scientific and technical programs for SKA and ASKAP.
    Creating a collaborative environment for scientists and engineers to engage and work with industry to produce studies, prototypes and systems linked to the overall scientific success of the SKA, MWA and ASKAP.

    SKA Murchison Widefield Array
    A Small part of the Murchison Widefield Array

    Enhancing Australia’s position in the international SKA program by contributing to the development process for the SKA in scientific, technological and operational areas.
    Promoting scientific, technical, commercial and educational opportunities through public outreach, educational material, training students and collaborative developments with national and international educational organisations.
    Establishing and maintaining a pool of emerging and top-level scientists and technologists in the disciplines related to radio astronomy through appointments and training.
    Making world-class contributions to SKA science, with emphasis on the signature science themes associated with surveys for neutral hydrogen and variable (transient) radio sources.
    Making world-class contributions to SKA capability with respect to developments in the areas of Data Intensive Science and support for the Murchison Radio-astronomy Observatory.

     
  • richardmitnick 12:06 pm on January 16, 2017 Permalink | Reply
    Tags: ASKAP finally hits the big-data highway, , , , ICRAR, , , , WALLABY - Widefield ASKAP L-band Legacy All-sky Blind surveY   

    From The Conversation for SKA: “The Australian Square Kilometre Array Pathfinder finally hits the big-data highway” 

    Conversation
    The Conversation

    SKA Square Kilometer Array

    SKA

    SKA/ASKAP radio telescope at the Murchison Radio-astronomy Observatory (MRO) in Mid West region of Western Australia
    SKA/ASKAP radio telescope at the Murchison Radio-astronomy Observatory (MRO) in Mid West region of Western Australia

    January 15, 2017
    Douglas Bock
    Director of Astronomy and Space Science, CSIRO

    Antony Schinckel
    ASKAP Director, CSIRO

    You know how long it takes to pack the car to go on holidays. But there’s a moment when you’re all in, everyone has their seatbelt on, you pull out of the drive and you’re off.

    Our ASKAP (Australian Square Kilometre Array Pathfinder) telescope has just pulled out of the drive, so to speak, at its base in Western Australia at the Murchison Radio-astronomy Observatory (MRO), about 315km northeast of Geraldton.

    ASKAP is made of 36 identical 12-metre wide dish antennas that all work together, 12 of which are currently in operation. Thirty ASKAP antennas have now been fitted with specialised phased array feeds, the rest will be installed later in 2017.

    Until now, we’d been taking data mainly to test how ASKAP performs. Having shown the telescope’s technical excellence it’s now off on its big trip, starting to make observations for the big science projects it’ll be doing for the next five years.

    And it’s taking lots of data. Its antennas are now churning out 5.2 terabytes of data per second (about 15 per cent of the internet’s current data rate).

    Once out of the telescope, the data is going through a new, almost automatic data-processing system we’ve developed.

    It’s like a bread-making machine: put in the data, make some choices, press the button and leave it overnight. In the morning you have a nice batch of freshly made images from the telescope.

    Go the WALLABIES

    The first project we’ve been taking data for is one of ASKAP’s largest surveys, WALLABY (Widefield ASKAP L-band Legacy All-sky Blind surveY).

    On board the survey are a happy band of 100-plus scientists – affectionately known as the WALLABIES – from many countries, led by one of our astronomers, Bärbel Koribalski, and Lister Staveley-Smith of the International Centre for Radio Astronomy Research (ICRAR), University of Western Australia.

    They’re aiming to detect and measure neutral hydrogen gas in galaxies over three-quarters of the sky. To see the farthest of these galaxies they’ll be looking three billion years back into the universe’s past, with a redshift of 0.26.

    2
    Neutral hydrogen gas in one of the galaxies, IC 5201 in the southern constellation of Grus (The Crane), imaged in early observations for the WALLABY project. Matthew Whiting, Karen Lee-Waddell and Bärbel Koribalski (all CSIRO); WALLABY team, Author provided

    Neutral hydrogen – just lonely individual hydrogen atoms floating around – is the basic form of matter in the universe. Galaxies are made up of stars but also dark matter, dust and gas – mostly hydrogen. Some of the hydrogen turns into stars.

    Although the universe has been busy making stars for most of its 13.7-billion-year life, there’s still a fair bit of neutral hydrogen around. In the nearby (low-redshift) universe, most of it hangs out in galaxies. So mapping the neutral hydrogen is a useful way to map the galaxies, which isn’t always easy to do with just starlight.

    But as well as mapping where the galaxies are, we want to know how they live their lives, get on with their neighbours, grow and change over time.

    When galaxies live together in big groups and clusters they steal gas from each other, a processes called accretion and stripping. Seeing how the hydrogen gas is disturbed or missing tells us what the galaxies have been up to.

    We can also use the hydrogen signal to work out a lot of a galaxy’s individual characteristics, such as its distance, how much gas it contains, its total mass, and how much dark matter it contains.

    This information is often used in combination with characteristics we learn from studying the light of the galaxy’s stars.

    Oh what big eyes you have ASKAP

    ASKAP sees large pieces of sky with a field of view of 30 square degrees. The WALLABY team will observe 1,200 of these fields. Each field contains about 500 galaxies detectable in neutral hydrogen, giving a total of 600,000 galaxies.

    3
    One of the first fields targeted by WALLABY, the NGC 7232 galaxy group. Ian Heywood (CSIRO); WALLABY team, Author provided

    This image (above) of the NGC 7232 galaxy group was made with just two nights’ worth of data.

    ASKAP has now made 150 hours of observations of this field, which has been found to contain 2,300 radio sources (the white dots), almost all of them galaxies.

    It has also observed a second field, one containing the Fornax cluster of galaxies, and started on two more fields over the Christmas and New Year period.

    Even more will be dug up by targeted searches. Simply detecting all the WALLABY galaxies will take more than two years, and interpreting the data even longer. ASKAP’s data will live in a huge archive that astronomers will sift through over many years with the help of supercomputers at the Pawsey Centre in Perth, Western Australia.

    ASKAP has nine other big survey projects planned, so this is just the beginning of the journey. It’s really a very exciting time for ASKAP and the more than 350 international scientists who’ll be working with it.

    Who knows where this Big Trip will take them, and what they’ll find along the way?

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    The Conversation US launched as a pilot project in October 2014. It is an independent source of news and views from the academic and research community, delivered direct to the public.
    Our team of professional editors work with university and research institute experts to unlock their knowledge for use by the wider public.
    Access to independent, high quality, authenticated, explanatory journalism underpins a functioning democracy. Our aim is to promote better understanding of current affairs and complex issues. And hopefully allow for a better quality of public discourse and conversation.

     
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