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  • richardmitnick 2:02 pm on July 11, 2021 Permalink | Reply
    Tags: "Thousands of galaxies classified in a blink of an eye", , , International Centre for Radio Astronomy Research - ICRAR   

    From CSIRO -Commonwealth Scientific and Industrial Research Organisation (AU) : “Thousands of galaxies classified in a blink of an eye” 

    CSIRO bloc

    From CSIRO -Commonwealth Scientific and Industrial Research Organisation (AU)

    July 8, 2021
    itchell Cavanagh (ICRAR/UWA)
    mitchell.cavanagh@icrar.org

    Cass Rowles (Media Contact, ICRAR)
    Ph: +61 420 976 086
    cass.rowles@icrar.org

    Jess Reid (Media Contact, University of Western Australia)
    Ph: +61 8 6488 6876
    E: jess.reid@uwa.edu.au

    Astronomers have designed and trained a computer program which can classify tens of thousands of galaxies in just a few seconds, a task that usually takes months to accomplish.

    In research published today [MNRAS], astrophysicists from Australia have used machine learning to speed up a process that is often done manually by astronomers and citizen scientists around the world.

    “Galaxies come in different shapes and sizes” said lead author Mitchell Cavanagh, a PhD candidate based at The University of Western Australia (AU) node of the International Centre for Radio Astronomy Research (ICRAR) (AU).

    “Classifying the shapes of galaxies is an important step in understanding their formation and evolution, and can even shed light on the nature of the Universe itself.”

    2
    Different shapes of galaxies, left to right: elliptical, lenticular, spiral, and irregular/miscellaneous. Credit: NASA/Hubble (elliptical galaxy M87), ESA/Hubble & NASA (lenticular galaxy NGC 6861 and the colliding Antennae galaxies), and David Dayag (the Andromeda spiral galaxy).

    Mr Cavanagh said that with larger surveys of the sky happening all the time, astronomers are collecting too many galaxies to look at and classify on their own.

    “We’re talking several million galaxies over the next few years. Sometimes citizen scientists are recruited to help classify galaxy shapes in projects like Galaxy Zoo, but this still takes time.”

    This is where convolutional neural networks, or CNNs, come in. In today’s high-tech world, these kinds of computer programs are everywhere, used in everything from medical imaging, stock markets and data analytics, to how Netflix generates recommendations based on your viewing history.

    In recent years, CNNs have begun to see wider adoption in astronomy. Most of the existing CNNs that astronomers use are binary – is this a spiral galaxy or not? – but this new CNN uses multiclass classification – is this an elliptical, lenticular, spiral, or irregular galaxy? – with more accuracy than the existing binary networks.

    Mr Cavanagh said that machine learning is becoming more widespread in astronomy.

    “The massive advantage of neural networks is speed. Survey images that would otherwise have taken months to be classified by humans can instead be classified in mere minutes.”

    “Using a standard graphics card, we can classify 14,000 galaxies in less than 3 seconds.”

    3
    The power of CNNs lies in their ability to extract features in images. Within the computer program, the convolutional layers are able to outline, trace and detect the presence of spiral arms or other features. Credit: Mitchell Cavanagh/International Centre for Radio Astronomy Research (ICRAR).

    “These neural networks are not necessarily going to be better than people because they’re trained by people, but they’re getting close with more than 80% accuracy, and up to 97% when classifying between ellipticals and spirals.”

    “If you place a group of astronomers into a room and ask them to classify a bunch of images, there will almost certainly be disagreements. This inherent uncertainty is the limiting factor in any AI model trained on labelled data.”

    3
    Being able to distinguish a lenticular galaxy from the other types can be difficult for human eyes, but the convolutional layers look for features we can’t see. Also, a CNN never tires, and if the image is flipped or rotated, that won’t cause the CNN to make a mistake. Credit: Mitchell Cavanagh/ICRAR.

    One great advantage of this new AI is that the researchers will be able to classify more than 100,000,000 galaxies at different distances (or redshifts) from Earth and in different environments (groups, clusters etc). This will help them understand how galaxies are being transformed over time, and why it might happen in particular environments.

    The CNNs that Mr Cavanagh has developed aren’t just for astronomy. They can be repurposed for use in many other fields, as long as they have a large enough dataset to train with.

    “CNNs will play an increasingly important role in the future of data processing, especially as fields like astronomy grapple with the challenges of big data,” he said.

    See the full article here .


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

    Please help promote STEM in your local schools.


    Stem Education Coalition

    CSIRO campus

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

    CSIRO works with leading organisations around the world. From its headquarters in Canberra, CSIRO maintains more than 50 sites across Australia and in France, Chile and the United States, employing about 5,500 people.

    Federally funded scientific research began in Australia 104 years ago. The Advisory Council of Science and Industry was established in 1916 but was hampered by insufficient available finance. In 1926 the research effort was reinvigorated by establishment of the Council for Scientific and Industrial Research (CSIR), which strengthened national science leadership and increased research funding. CSIR grew rapidly and achieved significant early successes. In 1949 further legislated changes included renaming the organisation as CSIRO.

    Notable developments by CSIRO have included the invention of atomic absorption spectroscopy; essential components of Wi-Fi technology; development of the first commercially successful polymer banknote; the invention of the insect repellent in Aerogard and the introduction of a series of biological controls into Australia, such as the introduction of myxomatosis and rabbit calicivirus for the control of rabbit populations.

    Research and focus areas

    Research Business Units

    As at 2019, CSIRO’s research areas are identified as “Impact science” and organised into the following Business Units:

    Agriculture and Food
    Health and Biosecurity
    Data 61
    Energy
    Land and Water
    Manufacturing
    Mineral Resources
    Oceans and Atmosphere

    National Facilities

    CSIRO manages national research facilities and scientific infrastructure on behalf of the nation to assist with the delivery of research. The national facilities and specialized laboratories are available to both international and Australian users from industry and research. As at 2019, the following National Facilities are listed:

    Australian Animal Health Laboratory (AAHL)
    Australia Telescope National Facility – radio telescopes included in the Facility include the Australia Telescope Compact Array, the Parkes Observatory, Mopra Observatory and the Australian Square Kilometre Array Pathfinder.

    .

    CSIRO Pawsey Supercomputing Centre AU)

    Others not shown

    SKA

    SKA- Square Kilometer Array

    .

     
  • richardmitnick 11:02 am on October 6, 2020 Permalink | Reply
    Tags: "Astronomers turn up the heavy metal to shed light on star formation", , , , , International Centre for Radio Astronomy Research - ICRAR   

    From International Centre for Radio Astronomy Research – ICRAR: “Astronomers turn up the heavy metal to shed light on star formation” 

    ICRAR Logo
    From International Centre for Radio Astronomy Research – ICRAR

    October 6, 2020

    Dr Sabine Bellstedt — ICRAR / University of WA
    +61 8 6488 7929
    Sabine.Bellstedt@icrar.org

    Associate Professor Aaron Robotham — (ICRAR / University of WA)
    +61 8 6488 5564
    Aaron.Robotham@icrar.org

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

    Jess Reid — Media Contact, University of Western Australia
    +61 8 6488 6876
    Jess.Reid@uwa.edu.au

    Astronomers from The University of Western Australia’s node of the International Centre for Radio Astronomy Research (ICRAR) have developed a new way to study star formation in galaxies from the dawn of time to today.

    “Stars can be thought of as enormous nuclear-powered processing plants,” said lead researcher Dr Sabine Bellstedt, from ICRAR.

    “They take lighter elements like hydrogen and helium, and, over billions of years, produce the heavier elements of the periodic table that we find scattered throughout the Universe today.

    “The carbon, calcium and iron in your body, the oxygen in the air you breathe, and the silicon in your computer all exist because a star created these heavier elements and left them behind,” Bellstedt said.

    “Stars are the ultimate element factories in the Universe.”

    Understanding how galaxies formed stars billions of years ago requires the very difficult task of using powerful telescopes to observe galaxies many billions of light-years away in the distant Universe.

    However, nearby galaxies are much easier to observe. Using the light from these local galaxies, astronomers can forensically piece together the history of their lives (called their star-formation history). This allows researchers to determine how and when they formed stars in their infancy, billions of years ago, without struggling to observe galaxies in the distant Universe.

    1
    Astronomers use galaxies near to Earth as a ‘local’ laboratory. Credit: ICRAR.

    Keck Observatory, two 10 meter telescopes operated by Caltech and the University of California, Maunakea Hawaii USA, altitude 4,207 m (13,802 ft).


    2
    A selection of the 7,000 galaxies used by the researchers in this work. Credit: GAMA Survey Team, ICRAR/UWA.

    Traditionally, astronomers studying star formation histories assumed the overall metallicity—or amount of heavy elements—in a galaxy doesn’t change over time.

    But when they used these models to pinpoint when stars in the Universe should have formed, the results didn’t match up with what they were seeing through their telescopes.

    3
    Artist’s impression. of the ProSpect code analysing a galaxy. Credit: ICRAR.

    “The results not matching up with our observations is a big problem,” Bellstedt said. “It tells us we’re missing something.”

    “That missing ingredient, it turns out, is the gradual build-up of heavy metals within galaxies over time.”

    Using a new algorithm to model the energy and wavelengths of light coming from almost 7000 nearby galaxies, the researchers succeeded in reconstructing when most of the stars in the Universe formed—in agreement with telescope observations for the first time.

    3
    Artist’s impression of the ProSpect code analysing a galaxy. Credit: ICRAR.

    Cosmic Star Formation
    The designer of the new code—known as ProSpect—is Associate Professor Aaron Robotham from ICRAR’s University of Western Australia node.

    “This is the first time we’ve been able to constrain how the heavier elements in galaxies change over time based on our analysis of these 7000 nearby galaxies,” Robotham said.

    “Using this galactic laboratory on our own doorstep gives us lots of observations to test this new approach, and we’re very excited that it works.

    “With this tool, we can now dissect nearby galaxies to determine the state of the Universe and the rate at which stars form and mass grows at any stage over the past 13 billion years.

    “It’s absolutely mind-blowing stuff.”

    5
    Analysing galaxies. Credit: ICRAR.

    This work also confirms an important theory about when most of the stars in the Universe formed.

    “Most of the stars in the Universe were born in extremely massive galaxies early on in cosmic history—around three to four billion years after the Big Bang,” Bellstedt said.

    “Today, the Universe is almost 14 billion years old, and most new stars are being formed in much smaller galaxies.”

    6
    Annotated graph showing the history of star formation from the Big Bang to now. Credit: ICRAR.

    Based on this research, the next challenge for the team will be to expand the sample of galaxies being studied using this technique, in an effort to understand when, where and why galaxies die and stop forming new stars.

    Bellstedt and Robotham, along with colleagues from Australia, the UK and the United States, are reporting their results in the scientific journal the Monthly Notices of the Royal Astronomical Society.

    More Information:

    The Galaxy And Mass Assembly (GAMA) is a decade long project to probe the evolution of mass, energy and structure on scales ranging from 1kpc to 1Mpc – measuring properties of the internal structures of galaxies, interacting pairs and mergers, the group environment and large-scale structure.

    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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