Tagged: SKA Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 8:06 am on August 22, 2017 Permalink | Reply
    Tags: , , , , , , , , SKA   

    From CSIRO blog: “Ernie Dingo visits our outback astronomy observatory – in his beloved backyard” 

    CSIRO bloc

    CSIRO blog

    22 August 2017
    Annabelle Young

    SKA Square Kilometer Array

    1
    Mr Ernie Dingo and Ms Leonie Boddington, our Aboriginal Liaison Officer, under one of the ASKAP antennas at the Murchison Radio-astronomy Observatory. No image credit.

    We searched far and wide for a place in Australia to build a world class radio astronomy observatory.

    The location had to be remote and far from man-made radio interference, to ensure quietness for these instruments to detect radio waves travelling from billions of light years away. It also needed to be somewhere relatively accessible for construction and observatory management.

    We found the perfect spot in the Murchison area of Western Australia, 700 kilometres northeast of Perth and in traditional Wajarri Yamatji country.

    It’s now home to our new Australian Square Kilometre Array Pathfinder telescope (ASKAP) and the Murchison Widefield Array telescope (MWA) led by Curtin University. It’s also a future site for the Square Kilometre Array (SKA) – the world’s largest and most ambitious international radio astronomy project ever realised.

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

    3
    ASKAP will capture radio images of the sky in more detail and faster than ever before. No image credit.

    4
    MWA, led by Curtin University

    Wajarri Yamatji Elder and Australian TV personality Ernie Dingo was passing by recently, so we invited him in for a tour and a chat about the Murchison Radio-astronomy Observatory (MRO), situated on his ancestral and beloved homeland.

    “This is where I come from, my home soil and I’m really glad the MRO is here to allow scientific visitors on Wajarri Yamatji ground. We are proud of our corner of the world, there are lots of secrets in the mid-west and it’s wonderful that this land has been adopted by scientists to unlock the secrets of the Universe.”

    Telescopes at the MRO will provide astronomers with the capability to answer fundamental questions about our Universe, such as the nature of cosmic magnetism and the evolution and formation of galaxies.

    Ernie is excited by the potential the facility brings to the local and global community; “It will inspire young people and further this part of the world. The antennas have a relatively small impact on the land, which is good from my point of view,” he said.

    Many partners have come together to create an Indigenous Land Use Agreement (ILUA) for the MRO to operate, and to ensure educational, social and economic benefits flow to the Wajarri Yamatji.

    The ILUA includes a cadetship program that runs for the life of the telescopes and our staff visit the remote Pia Community School as part of a mentoring program. We’ve co-created resources on Wajarri culture and the MRO. A new ILUA for the SKA will expand on these benefits.

    ASKAP’s 36 individual dish antennas spread out across a six kilometre area. In contrast to the rustic colours of the Australian outback, they’re bright white but Ernie says they fit in the landscape, like part of the furniture!

    “This is wildflower country and they’re like beautiful giant white wildflowers growing up out of the earth”.

    4
    Lechenaultia macrantha or Wreath Flower found near the MRO.

    On his visit Ernie finds bushfood growing under the telescope and although he recognises the site is generally closed to visitors for radio quiet purposes.

    “I hope the scientists get a chance to stop and smell the flowers – there’s plenty of bush food out here and it’s the only place in the world where the wreath flower grows.”

    CSIRO acknowledges the Wajarri Yamatji as the traditional custodians of the MRO site and gratefully acknowledge the important role the Wajarri Yamatji have played in enabling Australia to secure the rights to co-host the SKA.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    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.

    The CSIRO blog is designed to entertain, inform and inspire by generally digging around in the work being done by our terrific scientists, and leaving the techie speak and jargon for the experts.

    We aim to bring you stories from across the vast breadth and depth of our organisation: from the wild sea voyages of our Research Vessel Investigator to the mind-blowing astronomy of our Space teams, right through all the different ways our scientists solve national challenges in areas as diverse as Health, Farming, Tech, Manufacturing, Energy, Oceans, and our Environment.

    If you have any questions about anything you find on our blog, we’d love to hear from you. You can reach us at socialmedia@csiro.au.

    And if you’d like to find out more about us, our science, or how to work with us, head over to CSIRO.au

    Advertisements
     
  • richardmitnick 12:46 pm on August 16, 2017 Permalink | Reply
    Tags: , As time passes and we still haven’t detected WIMPs, , , , Can Radio Telescopes Find Axions?, , , Galactic halo model, Magnetic fields can change axions to and from photons, , , SKA   

    From AAS NOVA: “Can Radio Telescopes Find Axions?” 

    AASNOVA

    American Astronomical Society

    16 August 2017
    Susanna Kohler

    1
    A simulation showing the distribution of dark matter in the universe. [AMNH]

    Dark matter halo Image credit: Virgo consortium / A. Amblard / ESA

    In the search for dark matter, the most commonly accepted candidates are invisible, massive particles commonly referred to as WIMPs. But as time passes and we still haven’t detected WIMPs, alternative scenarios are becoming more and more appealing. Prime among these is the idea of axions.

    2
    The Italian PVLAS is an example of a laboratory experiment that attempted to confirm the existence of axions. [PVLAS]

    A Bizarre Particle

    Axions are a type of particle first proposed in the late 1970s. These theorized particles arose from a new symmetry introduced to solve ongoing problems with the standard model for particle physics, and they were initially predicted to have more than a keV in mass. For this reason, their existence was expected to be quickly confirmed by particle-detector experiments — yet no detections were made.

    Today, after many unsuccessful searches, experiments and theory tell us that if axions exist, their masses must lie between 10-6–10-3 eV. This is minuscule — an electron’s mass is around 500,000 eV, and even neutrinos are on the scale of a tenth of an eV!

    But enough of anything, even something very low-mass, can weigh a lot. If they are real, then axions were likely created in abundance during the Big Bang — and unlike heavier particles, they can’t decay into anything lighter, so we would expect them all to still be around today. Our universe could therefore be filled with invisible axions, potentially providing an explanation for dark matter in the form of many, many tiny particles.

    4
    Artist’s impression of the central core of proposed Square Kilometer Array antennas. [SKA/Swinburne Astronomy Productions]

    How Do We Find Them?

    Axions barely interact with ordinary matter and they have no electric charge. One of the few ways we can detect them is with magnetic fields: magnetic fields can change axions to and from photons.

    While many studies have focused on attempting to detect axions in laboratory experiments, astronomy provides an alternative: we can search for cosmological axions. Now scientists Katharine Kelley and Peter Quinn at ICRAR, University of Western Australia, have explored how we might use next-generation radio telescopes to search for photons that were created by axions interacting with the magnetic fields of our galaxy.

    5
    Potential axion coupling strengths vs. mass (click for a closer look). The axion mass is thought to lie between a µeV and a meV; two theoretical models are shown with dashed lines. The plot shows the sensitivity of the upcoming SKA and its precursors, ASKAP and MEERKAT. [Kelley&Quinn 2017]

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

    SKA Meerkat telescope, 90 km outside the small Northern Cape town of Carnarvon, SA

    Hope for Next-Gen Telescopes

    By using a simple galactic halo model and reasonable assumptions for the central galactic magnetic field — even taking into account the time dependence of the field — Kelley and Quinn estimate the radio-frequency power density that we would observe at Earth from axions being converted to photons within the Milky Way’s magnetic field.

    The authors then compare this signature to the detection capabilities of upcoming radio telescope arrays. They show that the upcoming Square Kilometer Array and its precursors should have the capability to detect signs of axions across large parts of parameter space.

    Kelley and Quinn conclude that there’s good cause for optimism about future radio telescopes’ ability to detect axions. And if we did succeed in making a detection, it would be a triumph for both particle physics and astrophysics, finally providing an explanation for the universe’s dark matter.

    Citation

    Katharine Kelley and P. J. Quinn 2017 ApJL 845 L4. doi:10.3847/2041-8213/aa808d

    Related Journal Articles
    See the full article for further references with links.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    1

    AAS Mission and Vision Statement

    The mission of the American Astronomical Society is to enhance and share humanity’s scientific understanding of the Universe.

    The Society, through its publications, disseminates and archives the results of astronomical research. The Society also communicates and explains our understanding of the universe to the public.
    The Society facilitates and strengthens the interactions among members through professional meetings and other means. The Society supports member divisions representing specialized research and astronomical interests.
    The Society represents the goals of its community of members to the nation and the world. The Society also works with other scientific and educational societies to promote the advancement of science.
    The Society, through its members, trains, mentors and supports the next generation of astronomers. The Society supports and promotes increased participation of historically underrepresented groups in astronomy.
    The Society assists its members to develop their skills in the fields of education and public outreach at all levels. The Society promotes broad interest in astronomy, which enhances science literacy and leads many to careers in science and engineering.

    Adopted June 7, 2009

     
  • richardmitnick 4:26 pm on August 11, 2017 Permalink | Reply
    Tags: , SKA, Supercomputing together   

    From CERN and SKA: “SKA and CERN co-operate on extreme computing” 

    SKA Square Kilometer Array

    1
    Big-data co-operation agreement

    On 14 July, the Square Kilometre Array (SKA) organisation signed an agreement with CERN to formalize their collaboration in the area of extreme-scale computing. The agreement will address the challenges of “exascale” computing and data storage, with the SKA and the Large Hadron Collider (LHC) to generate an overwhelming volume of data in the coming years.

    When completed, SKA will be the world’s largest radio telescope with a total collecting area of more than 1 km2 using thousands of high-frequency dishes and many more low- and mid-frequency aperture array telescopes distributed across Africa, Australia and the UK. Phase 1 of the project, representing approximately 10% of the final array, will generate around 300 PB of data every year – 50% more than has been collected by the LHC experiments in the last seven years. As is the case at CERN, SKA data will be analysed by scientific collaborations distributed across the planet. The acquisition, storage, management, distribution and analysis of such volumes of scientific data is a major technological challenge.

    “Both CERN and SKA are and will be pushing the limits of what is possible technologically, and by working together and with industry, we are ensuring that we are ready to make the most of this upcoming data and computing surge,”says SKA director-general Philip Diamond.

    CERN and SKA have agreed to hold regular meetings to discuss the strategic direction of their collaborations, and develop demonstrator projects or prototypes to investigate concepts for managing and analysing exascale data sets in a globally distributed environment. “The LHC computing demands are tackled by the Worldwide LHC computing grid, which employs more than half a million computing cores around the globe interconnected by a powerful network,” says CERN’s director of research and computing Eckhard Elsen. “As our demands increase with the planned intensity upgrade of the LHC, we want to expand this concept by using common ideas and infrastructure into a scientific cloud. SKA will be an ideal partner in this endeavour.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
  • richardmitnick 2:49 pm on June 22, 2017 Permalink | Reply
    Tags: , SKA, What Ethan left out   

    From Ethan Siegel: “The future of astronomy: thousands of radio telescopes that can see beyond the stars” 

    Ethan Siegel
    June 21, 2017

    [SO, DID ETHAN FINALLY DISCOVER SKA? IT LOOKS LIKE THAT IS TRUE. I DID A SEARCH, “ETHAN SIEGEL AND SKA” AND CAME UP WITH NOTHING BUT THIS POST. ETHAN, WHAT ROCK HAVE YOU BEEN LIVING UNDER? COME BACK TO ME AND ENLIGHTEN ME.]

    The future of astronomy: thousands of radio telescopes that can see beyond the stars.

    1
    The Square Kilometer Array will, when completed, be comprised of an array of thousands of radio telescopes, capable of seeing farther back into the Universe than any observatory that has measured any type of star or galaxy. Image credit: SKA Project Development Office and Swinburne Astronomy Productions.

    Never heard of SKA, the square kilometer Array? Once it starts taking data, you’ll never forget it.

    SKA Square Kilometer Array

    SKA South Africa

    “Not all chemicals are bad. Without chemicals such as hydrogen and oxygen, for example, there would be no way to make water, a vital ingredient in beer.” -Dave Barry

    By building bigger telescopes, going to space, and looking from ultraviolet to visible to infrared wavelengths, we can view stars and galaxies as far back as stars and galaxies go. But for millions of years in the Universe, there were no stars, no galaxies, nor anything that emitted visible light. Prior to that, the only light that existed was the leftover glow from the Big Bang, along with the neutral atoms created during the first few hundred thousand years.

    CMB per ESA/Planck

    ESA/Planck

    For those millions of years, there’s simply never been a way to gather information from the electromagnetic part of the spectrum. But a combination of advances in computing and the new construction of an array of thousands of large-scale radio telescopes across twelve countries opens up an incredible possibility like never before: the ability to map the neutral atoms themselves.

    2
    Distant sources of light — even from the cosmic microwave background [CMB, above] — must pass through clouds of gas. If there’s neutral hydrogen present, it can absorb that light, or, if it’s excited in some way, it can emit light of its own. Image credit: Ed Janssen, ESO [Includes inage of ESO’s VLT at Cerro Paranel, Chile].

    How can you see neutral atoms? After all, unless you’re dealing in either reflected light or with atoms that are themselves in an excited state, neutral atoms are some of the most optically boring materials that there are. Atoms are made of negatively charged electrons surrounding a positively charged nucleus, capable of occupying a variety of quantum states. But early on, for millions of years after the Big Bang, 92% of the atoms are the most boring type that exists: hydrogen, with a single proton and electron. While many different energy states exist, without any external source to excite it, hydrogen atoms are doomed to live in the lowest-energy (ground) state.

    3
    The energy levels and electron wavefunctions that correspond to different states within a hydrogen atom. The energy levels are quantized in multiples of Planck’s constant, but even the lowest energy, ground state has two possible configurations depended on the relative electron/proton spin. Image credit: PoorLeno of Wikimedia Commons.

    But when you first make neutral hydrogen, not all the atoms are perfectly in the ground state. You see, in addition to energy levels, the particles in atoms also have a property called spin: their intrinsic angular momentum. A particle like a proton or an electron can either be spin up (+½) or spin down (-½), and so a hydrogen atom can either have the spins aligned (both up or both down) or anti-aligned (one up and the other down). The anti-aligned combination is slightly lower in energy, but not by much. The transition from an aligned state to an anti-aligned one takes millions of years to occur, and when it does, the atom emits a photon of a very particular wavelength: 21 centimeters.

    4
    The 21-centimeter hydrogen line comes about when a hydrogen atom containing a proton/electron combination with aligned spins (top) flips to have anti-aligned spins (bottom), emitting one particular photon of a very characteristic wavelength. Image credit: Tiltec of Wikimedia Commons.

    Every time you undergo a burst of star formation, you ionize hydrogen atoms, meaning that electrons will fall back onto protons eventually, forming a large number of aligned atoms. By looking for this 21-cm signal, we can:

    construct a map of nearby, recent star formation,
    detect absorbing, neutral sources of anti-aligned gas,
    build a 3D map of neutral gas throughout the Universe,
    detect how star clusters and galaxies formed and evolved over time,
    and possibly detect the absorption and emission features of hydrogen gas immediately after, during, and possibly even before the formation of the first stars.

    5
    Before the formation of the first stars, there’s still neutral hydrogen gas to observe, if we look for it in the right way. Image credit: European Southern Observatory.

    Lambda-Cold Dark Matter, Accelerated Expansion of the Universe, Big Bang-Inflation (timeline of the universe) Date 2010 Credit: Alex MittelmannColdcreation


    Somehow, this image seems fitting at this point.

    Next year, in 2018, just as the James Webb Space Telescope prepares for launch,

    NASA/ESA/CSA Webb Telescope annotated

    construction will begin on the Square Kilometer Array (SKA) [This is not correct. much has already been done. If Ethan skips over it, I will not let it pass uncovered.] SKA will wind up, at completion, being an array of some 4,000 radio telescopes, each approximately 12 meters in diameter, and capable of detecting this 21-cm line back farther than any galaxy we’ve ever seen. While the current galactic record-holder comes from when the Universe was just 400 million years old — 3% of its current age — SKA should be able to get the first 1% of the Universe that even James Webb might not see.

    6
    Only because this distant galaxy, GN-z11, is located in a region where the intergalactic medium is mostly reionized, can Hubble reveal it to us at the present time. James Webb will go much farther, but SKA will image the hydrogen that’s invisible to all other optical and infrared observatories. Image credit: NASA, ESA, and A. Feild (STScI).

    To go beyond the first stars, or to arrive at a cosmic destination where no ultraviolet or visible light can pass through the opaque, intergalactic medium, you need to probe what’s actually there. And in this Universe, the overwhelming majority of what’s there, at least that we can detect, is hydrogen. That’s what we know is out there, and that’s what we’re building SKA with the intention of seeing. It will collect more than ten times the data per second than any array today; it will have more than ten times the data collecting power; and it is expected to map the entire Universe from here all the way back to before the first galaxies. We will learn, in the most powerful way ever, how stars, galaxies, and the gas in the Universe grew up and evolved over time.

    7
    A single dish that’s currently part of the MeerKAT array will be incorporated into the Square Kilometer Array, along with around 4,000 other equivalent dishes. Image credit: SKA Africa Technical Newsletter, 1 (2016).

    A better image, and this is just South Africa:

    SKA Meerkat telescope, 90 km outside the small Northern Cape town of Carnarvon, SA

    According to Simon Ratcliffe, SKA scientist, we know some of what we’re going to find with SKA, but it’s the unknowns that are the most exciting.

    “Every time we’ve set out to measure something, we’ve discovered something entirely surprising.”

    Radio astronomy has brought us pulsars, quasars, microquasars, and mysterious sources like Cygnus X-1, which turned out to be black holes. The entire Universe is out there, waiting for us to discover it. When SKA is completed, it will shed a light on the Universe beyond stars, galaxies, and even gravitational waves. It will show us the invisible Universe as it truly is. As with anything in astronomy, all we need to do is look with the right tools.

    O.K., not O.K., here is some of what Ethan did not include:

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

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

    Artist’s impression of the Mid-Frequency Aperture Array telescope when deployed on the African site (C) SKA Organisation

    SKA LOFAR core (“superterp”) near Exloo, Netherlands

    6
    EMBRACE is the Electronic MultiBeam Radio Astronomy ConcEpt which is the Pathfinder instrument for the SKA at frequencies between 500MHz and 1500MHz.

    Seriously, Ethan, come back to me and tell me why you did not include these assets. After that, do a serious piece on Radio Astronomy that includes the Jansky VLA, the EHT, the European VLBI, The Global mm-VLBI Array, the NRAO VLBA. GBO, Parkes, The Goldstone Deep Space Communications Complex, NASA’s DEEP SPACE NETWORK, and whatever else is slipping my mind. I could put in all of the images because I have them. But, you are fantastic with images, so I will leave it to you to do it right.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    “Starts With A Bang! is a blog/video blog about cosmology, physics, astronomy, and anything else I find interesting enough to write about. I am a firm believer that the highest good in life is learning, and the greatest evil is willful ignorance. The goal of everything on this site is to help inform you about our world, how we came to be here, and to understand how it all works. As I write these pages for you, I hope to not only explain to you what we know, think, and believe, but how we know it, and why we draw the conclusions we do. It is my hope that you find this interesting, informative, and accessible,” says Ethan

     
  • richardmitnick 9:34 pm on June 5, 2017 Permalink | Reply
    Tags: , , , , Natasha Hurley-Walker, , SKA,   

    From SKA: Women in STEM – Natasha Hurley-Walker 

    SKA Square Kilometer Array

    SKA

    1

    On International Women’s Day 2017, we sat down with Australian astronomer Dr. Natasha Hurley-Walker, who just completed a two-month fellowship at the SKA Headquarters in the UK, to chat about her work, her background, and women in science.

    For a lot of people working in science fields, their interest in science was sparked when they were young. How did you get into astronomy?

    Ever since I first saw an episode of Star Trek I wanted to know more about space and was inspired by my visits to NASA’s Johnson Space Centre while I was living in Houston, Texas, during childhood. My parents fed my interest giving me access to as many science fictions and books as I could read, and I pursued mathematics and science at school.

    When it came to choose a path through university, I was strongly drawn to physics, which I felt was the only discipline that comes close to explaining how the universe operates.

    Looking back at your own path, what would you say characterises a career in astronomy?

    Travel! This might sound surprising to a lot of people but astronomers travel a lot. We study and work in different countries to acquire experience and collaborate on research with colleagues from around the world, which is very rewarding.

    I did my undergraduate degree at the University of Bristol in the UK, and in the summer after my third year I joined the summer astronomy program at Jodrell Bank Observatory near Manchester and enjoyed the experience so much that I continued my research project as my Master project. During this period I discovered a previously unknown pulsar in the data I was working with, a huge reward for my hard work!

    After my Master’s, I was accepted for a PhD position at the University of Cambridge. There, as part of a small team of students, scientists, and engineers, I helped to commission a new radio telescope and performed some of its first science observations, which was very exciting.

    2
    Natasha working on the MWA. http://skatelescope.org/wp-content/uploads/2017/03/NHW_Beta_receiver.jpg

    I then took up a Super Science Fellowship in Australia to help with the commissioning of the Murchison Widefield Array (MWA), the SKA-low precursor in Western Australia.

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

    I helped develop the software and data reduction processes to turn the raw data into usable images of the sky. This gave me a fantastic opportunity to use a brand new telescope as well as travel the world working on science projects with brilliant people. These collaborations have meant travelling to the USA, India, New Zealand, and all around Europe.

    I’m now an Early-Career Research Fellow at Curtin University in Australia. With the help of colleagues, I recently developed an extensive map of the southern radio sky mapping some 300,000 galaxies that can be used to model what the SKA will observe (read more).

    I recently undertook a two-month fellowship at the SKA Headquarters at Jodrell Bank in the UK to work with the science team there on expanding this idea into building the first surveys with the future SKA-low telescope.

    Lots of travel indeed! Another thing that seems to stand out from your experience is fine-tuning telescopes – almost like a mechanic – and the excitement of discovering something new. Would you say that’s a big motivation?

    Absolutely! What I enjoy about my job is solving a myriad of technical and scientific problems. It’s very satisfying to separate artefacts produced by the instrument from actual data, obtaining as close as possible an image of the real sky.

    Every so often I discover something completely unexpected and new, which is such a fantastic feeling. Recently I discovered an ancient radio galaxy which has nearly completely died. It’s the faintest one ever found, and interestingly the jets are coming from a spiral galaxy like our own rather than a more typical elliptical – that is very unusual because we only know of a few such examples out of hundreds of thousands of radio galaxies.

    What about the work environment? Astronomy, like many other sciences, suffers from a reputation of being a male-dominated environment, has this affected you personally?

    3

    Even if I don’t feel gender discrimination or imbalance in my job I’m quite aware of the unconscious bias that may lead to my work and thoughts being undervalued. But aside from standing up for myself, I am helped by the men of my generation who tend to notice that sort of thing, and act as supportive allies when such situation arises.

    Occasionally at conferences or in meetings I notice the gender balance is male-skewed. Then again, in some fields, it’s now female-skewed. I feel that my work environment is very similar for women as it is for men. Last year marked my return from six months of maternity leave, which I was initially worried would heavily impact my work. While it hasn’t been perfectly straightforward coming back – I certainly can’t work ten-hour days when I feel like it anymore – my university and my colleagues have been very supportive and understanding. While I by necessity work fewer hours, I also now work “smarter”, knowing that my time is very precious and I need to spend it wisely.

    Flexible working practices like the ability to work from home when necessary, and the no-questions-asked one hour per day of leave that the university gives staff members returning from parental leave, have been extremely beneficial in helping me transition smoothly back into work.

    People from all over the world work on the SKA. We know that diversity in the workplace helps provide a healthy mix of ideas and solutions to problems that makes companies more successful, and yet it is a topic that is still sometimes poorly understood. What can be done to help improve awareness of its importance?

    I highly recommend facilitated workshops on unconscious bias. There is a large amount of research on bias in hiring procedures, in promotions, in workplace interactions, and as scientists we should all be open to using evidence to implement best practice. The workshops can be surprisingly fun: we ran one as part of the 2013 Women in Astronomy meeting in Perth, and many people commented that they learned a lot both about their workplaces and also about their own biases. For a fun test you can try at home, have a look at Project Implicit based at Harvard University. Award programmes like the Pleiades Awards and Athena Swan provide best-practice frameworks for organisations to improve their environments to promote equity, and their gold accreditations should be something all organisations aspire to achieving.

    Before we finish, inspiring the next generation to study STEM (Science, Technology, Engineering and Maths) fields is an important part of what we do. What would you say to a young person who is interested in science but unsure about their study or career path?

    Follow your dreams and listen to your heart. Don’t take other people’s feeling into consideration, do what is right for YOU. You’ll know if you’re in the wrong path, because you’ll constantly be thinking about something else. If you get that feeling, look at your options, and change direction.

    Finally, we’re told that when you’re not busy discovering new radio galaxies you’re into board games and cycling. Tell us more!

    I absolutely adore board games; proper worker-placement Euros like Caylus, strategic PVPs like Robo Rally, and traitor games like Battlestar Galactica. I’m also a keen transport cyclist: in my family we have three bicycles, a tandem, a trailer, and a balance bike for my toddler son. I’m thinking about getting an e-bike, too! I think cycling is a win on all counts: great for the environment, fantastic for my health, a great mood-booster and mind-clearer at the start and end of the day, and it sure is faster, cheaper, and more fun than queuing in traffic. I also love science fiction, especially novels and the more mind-bending (and probably more obscure) TV shows and movies. I also enjoy cooking and have a food blog, sadly very rarely updated nowadays, but I have a lot to do!

    In December 2016 Natasha gave a great TEDxTalk in Perth about her work. Take a look!

    See the full article here .

    Please help promote STEM in your local schools.
    STEM Icon

    Stem Education Coalition

    SKA Banner

    SKA CSIRO  Pathfinder Telescope
    SKA ASKAP Pathefinder Telescope

    SKA Meerkat telescope
    SKA Meerkat Telescope

    SKA Murchison Widefield Array
    SKA Murchison Wide Field Array

    About SKA

    The Square Kilometre Array will be the world’s largest and most sensitive radio telescope. The total collecting area will be approximately one square kilometre giving 50 times the sensitivity, and 10 000 times the survey speed, of the best current-day telescopes. The SKA will be built in Southern Africa and in Australia. Thousands of receptors will extend to distances of 3 000 km from the central regions. The SKA will address fundamental unanswered questions about our Universe including how the first stars and galaxies formed after the Big Bang, how dark energy is accelerating the expansion of the Universe, the role of magnetism in the cosmos, the nature of gravity, and the search for life beyond Earth. Construction of phase one of the SKA is scheduled to start in 2016. The SKA Organisation, with its headquarters at Jodrell Bank Observatory, near Manchester, UK, was established in December 2011 as a not-for-profit company in order to formalise relationships between the international partners and centralise the leadership of the project.

    The Square Kilometre Array (SKA) project is an international effort to build the world’s largest radio telescope, led by SKA Organisation. The SKA will conduct transformational science to improve our understanding of the Universe and the laws of fundamental physics, monitoring the sky in unprecedented detail and mapping it hundreds of times faster than any current facility.

    Already supported by 10 member countries – Australia, Canada, China, India, Italy, New Zealand, South Africa, Sweden, The Netherlands and the United Kingdom – SKA Organisation has brought together some of the world’s finest scientists, engineers and policy makers and more than 100 companies and research institutions across 20 countries in the design and development of the telescope. Construction of the SKA is set to start in 2018, with early science observations in 2020.

     
  • richardmitnick 2:24 pm on February 27, 2017 Permalink | Reply
    Tags: , , , SKA, SKA: Tooling up down under for the world's most powerful telescope   

    More about SKA – “SKA: Tooling up down under for the world’s most powerful telescope” 

    Cosmos Magazine bloc

    COSMOS

    27 February 2017
    Elizabeth Finkel

    1
    SKA will not only take us to the edge of the universe, it will revolutionise computing. Dragonfly Media / CSIRO

    On a flat, red mulga plain in the outback of Western Australia, preparations are under way to build the most audacious telescope astronomers have ever dreamed of – the Square Kilometre Array (SKA).

    SKA Square Kilometer Array

    Next-generation telescopes usually aim to double the performance of their predecessors. The Australian arm of SKA will deliver a 168-fold leap on the best technology available today, to show us the universe as never before. It will tune into signals emitted just a million years after the Big Bang, when the universe was a sea of hydrogen gas, slowly percolating with the first galaxies. Their starlight illuminated the fledgling universe in what is referred to as the “cosmic dawn”.

    “It is the last non-understood event in the history of the universe,” says Stuart Wyithe, a theoretical astrophysicist at the University of Melbourne in Australia.

    Like any dream, realisation is the hard part. In 2018, when the first of 130,000 Christmas-tree-like antennae is deployed on the sandy plains of Murchison, an almost uninhabited district of 50,000 square kilometres, it will mark 28 years since its conception.

    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

    SKA Murchison Widefield Array
    SKA Murchison Widefield Array

    Epic battles have brought the project to this point – most famously the six-year contest between countries to host the telescope. Australia and South Africa ended up sharing the prize. The SKA’s telescope in South Africa will be built on another flat, red flat plain – the Karoo region of the North Cape.

    SKA Icon

    It has somewhat less lofty ambitions – its dishes will probe only halfway to the edge of the universe. Its moniker, SKA-mid, denotes the mid-range frequencies of radio waves stretched across this distance.

    Australia’s SKA-low, by contrast, will tune into the low frequencies emanating from the extremities of the cosmos. Together the two telescopes will represent “the largest science facility on the planet,” says SKA director-general and radio astronomer Phil Diamond, who is based at Jodrell Bank Observatory in the UK.

    3
    Artist’s impression of the expansion to the current headquarters at Jodrell Bank at U Manchester proposed by the UK

    The game-changing technology that will allow us to hear the whispers of newborn stars against the cacophony of the universe doesn’t involve grinding mirrors to atom-thin smoothness or constructing dishes the size of sports fields. The disruptive technology here is supercomputing.

    Once SKA-low is running, it will generate more data every day than the world’s internet traffic. Dealing with this deluge is a challenge being tackled by hefty global collaborations of academia and private enterprise – and it is by no means clear how it will be solved. “It’s a scale no one has attempted before,” says Peter Quinn, a computational astrophysicist at the University of Western Australia, and director of the International Centre for Radioastronomy Research (ICRAR) in Perth.

    ICRAR Logo

    While international mega-science projects have been tackled before – think the European Organisation for Nuclear Research (CERN), which operates the world’s largest particle accelerator, the Large Hadron Collider – when it comes to the SKA, the potential world-changing spin-offs have never been so blazingly obvious.

    CERN didn’t just find the Higgs boson – computer scientist Tim Berners-Lee created the World Wide Web to manage its information sharing. Wi-Fi was the spin-off when Australian CSIRO astronomers developed ways to realign scrambled radio signals from black holes.

    Mega-corporations such as CISCO, Woodside, Chevron, Rio Tinto and Google are already positioned to collaborate with SKA astronomers around the world.

    A science project of this grandeur, managed across 10 countries, involving dozens of specialist technical consortia and thousands of people, is challenging enough. The question of how to divvy up the pie for construction contracts and the commercial spin-offs that follow adds a whole new, complicated layer.

    But astronomers have a great track record when it comes to teasing their way through gnarly collaborations to deliver triumphs such as the Hubble Space Telescope and the Atacama Large Millimeter Array.

    NASA Hubble Telescope
    NASA/ESA Hubble 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

    After nearly 25 years of wrangling, the signs are that the first binding SKA treaty will be signed early next year, committing the 10 member countries – Australia, Canada, China, India, Italy, New Zealand, South Africa, Sweden, the Netherlands and the UK – to funding and contracts for the 2018 rollout.

    Even with the treaty, SKA will remain a confusing beast: not one telescope but two, located in two countries, with headquarters in a third – the UK. Despite the name, neither of the Phase 1 telescopes slated for construction actually boasts a square kilometre of collecting area. That won’t be realised until Phase 2 of the project, negotiations for which have yet to begin.

    Nevertheless, as the gears of the vast project slowly grind into action, Australia is bracing to host its first global mega-science project. “It will be our CERN downunder,” says CSIRO astronomer Sarah Pearce, Australia’s science representative to the SKA board. But, she adds, “don’t expect a tour. It’s here precisely because there are very few people.”

    5
    The 200 dishes of SKA-mid to be rolled out in South Africa will probe half way to the edge of the universe. SKA Organisation / Eye Candy Animation (Artist’s impression)

    An idea takes root

    The curious thing about astronomy is that telescopes, as they grow more powerful, turn into time machines. When Galileo peered at Jupiter, he saw it as it appeared some 42 minutes earlier – the time it took for its light to reach him. Hubble’s iconic image of the Horsehead Nebula in the constellation of Orion is a snapshot of how it looked 1,500 years ago.

    Horsehead Emission nebula
    Horsehead Emission nebula

    The astronomers who conceived the SKA had their sights set way beyond the 100,000-light-year dimensions of our own galaxy. The faint signals they seek began their journey more than 13 billion years ago, just a few million years after the Big Bang.

    At that point, the hot plasma of electrons and protons had cooled enough to fuse and form the simplest atom – hydrogen. Except for a slight ripple here or there, our universe was a featureless sea of it. Today, things are different – the sea is dotted with galaxies. But how did these galactic islands form? To find out requires a telescope that can look back to the rippling hydrogen sea of 13 billion years ago. “That’s why the SKA was originally called the ‘hydrogen telescope’,” Quinn says.

    Those who imagined the SKA had a lust for hydrogen. Their appetite had been whet by the Very Large Array (VLA), 27 dishes lying 80km west of Socorro, in New Mexico.

    NRAO/VLA, on the Plains of San Agustin fifty miles west of Socorro, NM, USA
    NRAO/VLA, on the Plains of San Agustin fifty miles west of Socorro, NM, USA

    Now known as the Jansky VLA, the telescope generated some of the first detailed maps of atomic hydrogen. The bond between hydrogen’s electron and proton emits a unique 21-centimetre radio wave. Because the universe is expanding, the waves emitted from outer space have stretched by the time they reach us. The futher away, the greater the stretching; hydrogen waves emanating from the edge of the universe measure 1.5m by the time they reach Earth. It’s known as the Doppler effect; on Earth, we experience it when we hear the sound of an ambulance siren deepen as it speeds away, its sound wave stretching as it goes.

    In 1990, on the 10th anniversary of the VLA, the world’s radio astronomers met to celebrate one of the New Mexico facility’s crowning achievements – mapping hydrogen in nearby galaxies. Ron Ekers, an Australian former director of the array, recalls that “everyone was on a high”.

    Not content to rest on their laurels, a small group of visionary astronomers wondered how far the technology could be pushed. Egged on, Peter Wilkinson from the University of Manchester in Britain pitched the idea of reaching out to galaxies at the edge of the universe. A total collecting area of one square kilometre, he figured, should do the job.

    The audacity of the proposal was amazing, Quinn says: “Most telescope improvements aim for a two-to-three-fold increase; this proposal represented a 10,000-fold increase.” That figure reflected a 50-fold increase in sensitivity multiplied by a 200-fold increase in field of view. “The goal was to see a milky way at the edge of the universe,” Quinn adds – and to scour the entire southern sky.

    The breakthrough technology needed to enable this leap did not lie in fancy new telescope designs, but in the explosion of computing power and techniques able to handle massive amounts of data.

    The receivers themselves could be little more than antennas. Tuned to radio wavelengths, they would pick up the extra-long waves of distant hydrogen – coincidentally the same wavelength used by many FM radio stations. “This is where the early universe is broadcasting,” says Quinn. “You just can’t hear it because it’s buried in the crackle.”

    The more antennae, the greater the sensitivity – hence the planned one square kilometre of collecting surface. But the antennae don’t need to be all in one spot. Indeed, the more spread out they are, the sharper the focus.

    How does a forest of radio antennae figure out where in the sky a signal has come from? Interferometry, a technique developed by British and Australian radio astronomers in the 1940s, is the key. It relies on the principle that each antenna in an array receives a signal at a slightly different time. For instance, radio waves coming from the easterly part of the sky hit the eastern-most antennae earlier than those lying further west. By electronically tweaking the delay on each, the entire forest could be made to point in a particular direction of the sky.

    But using interferometry to tune into signals from the edge of the universe would have required filtering astronomical amounts of data; and that was a challenge yet to be mastered.

    6
    Like a forest of metal pine trees: an artist’s impression of some of the 130,000 antennae of SKA-low to be assembled on the red plains of Murchison. They will probe to the edge of the universe.
    SKA Organisation / Eye Candy Animation

    The tussle

    In 2000, a SKA steering committee led by Ekers invited proposals for a home for the telescope. Five countries responded. To help their bid, some built serious prototypes known as “pathfinders”. It resulted in an astronomical bonanza. Australia built the majestic dishes of the Australian Square Kilometre Array Pathfinder (ASKAP) and the antenna forest of the Murchison Widefield Array (MWA).

    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

    South Africa built the seven dishes of KAT-7 and is building the larger SKA Meerkat telescope, 90 km outside the small Northern Cape town of Carnarvon, SA.
    “SKA Meerkat telescope, 90 km outside the small Northern Cape town of Carnarvon, SA

    China began work on a prototype which paved the way for the Five-hundred-metre Aperture Spherical radio Telescope (FAST), the largest single radio dish in the world.

    FAST Chinese Radio telescope , being built at Guizhou Province, China
    FAST Chinese Radio telescope , being built at Guizhou Province, China

    FAST radio telescope, now operating  located in the Dawodang depression in Pingtang county Guizhou Province, South China
    “FAST radio telescope, now operating located in the Dawodang depression in Pingtang county Guizhou Province, South China

    Geography worked against some of the contestants. The Chinese site wasn’t flat enough. The joint Brazilian-Argentinian bid was let down by a turbulent ionosphere – the uppermost layer of the atmosphere – which distorted the sought-after low frequency radio waves.

    By 2006, Australia and South Africa were the last countries standing. Both laid claim to vast unpopulated regions, free of radio wave interference and with relatively placid ionospheres.

    The South African site’s higher elevation was in its favour. Australia, on the other hand, had an impressive track record in radio astronomy. It boasted some of the world’s first interferometers, built in the 1940s at Dover Heights south of Sydney, and the iconic CSIRO Parkes telescope, operating since 1961.

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

    The contest was fierce, and for good reason: SKA’s benefits clearly stretched far beyond astronomy. “The devices and algorithms developed to pursue SKA’s goals may be the next Wi-Fi, the next multi-trillion dollar technology market,” says Steven Tingay, the former director of the MWA who now leads Italy’s SKA involvement. Whichever country hosted the SKA would be at the heart of the action, attracting and training the next generation of engineers and scientists in advanced manufacturing, telecommunications and high-performance computing.

    Accompanied by the sort of media attention usually reserved for a football grand final, a competitive and secretive bidding process ensued.

    In May 2012, members of the SKA organisation voted to split the array between the Australian and African sites. The South African telescope would observe radio waves from 350 MHz to 14 gigahertz, enabling it to detect signals up to six billion light-years away – a still sparse chapter in the universe’s life story. It would use dishes like those of the JVLA, but dramatically increase speed and sensitivity.

    Australia’s array would detect frequencies in the range of 50 to 350 MHz – ideal for detecting hydrogen signals from the edge of the universe.

    Both would rely on the development of disruptive new computation techniques.

    “We believe we know how to do it, but I’m not hiding the fact that it’s a challenge,” Diamond says.

    7
    The Murchison Widefield Array is the prototype for the SKA-low. This composite image from the GLEAM survey shows how the Milky Way appears at radio wavelengths.
    Radio image: Natasha Hurley-Walker (ICRAR / Curtin) / GLEAM Team. MWA tile and landscape: Dr John Goldsmith / Celestial Visions.

    Building it

    Getting to the Australian site of the SKA gives the words “isolation” and “quiet” whole new meanings. First, you make your way to Perth, itself one of the most isolated cities in the world. Then it’s another one-hour flight to the 35,000-strong port town of Geraldton. From there, bump around for four dusty hours in a four-wheel-drive until finally, on the horizon, you see a succession of towering white 12-metre telescope dishes.

    You have arrived at the Murchison Radio-astronomy Observatory. The 36 dishes comprise ASKAP. Despite the name, they are not the prototype for SKA-low. That honour goes to the MWA, a rather less majestic affair that lies hidden in the nearby mulga scrub: 2,048 squat, wiry antennae, resembling a swarm of giant spiders. Unlike ASKAP, the MWA has no moving parts to point to different parts of the sky. That’s because this is a software telescope. It relies on a computer to program different delays into the antennae so signals from the same patch of sky are collected at the same time.

    Amid great fanfare, MWA first came online in mid-2013. According to director Randall Wayth, it has blazed the trail for SKA-low. It is tuned to receive signals from the early universe within the bandwidth of 80 to 300 MHz. It does not have the sensitivity to detect features of the cosmic dawn, but its impressive 30-degree field of view allows it to map the entire visible sky over a few nights. The Galactic and Extragalactic All-sky MWA (GLEAM) survey, for instance, mapped bubbles of ionised hydrogen gas and quasars from up to six billion light years away.

    Two trail-blazing aspects of its operation are key to SKA-low. The first is that it has pioneered methods to adjust for the distorting effects of the ionosphere above Murchison. “It’s like trying to see something at the bottom of a rippling pool,” explains Wayth. “Luckily for us, it’s usually just small ripples.”

    Filtering out the ripples of the ionosphere is just one step in a multipronged data-processing operation whose ultimate aim is to deliver sharp images of the ancient universe.

    Another early step reduces the noise inherent in the system. The heart of every radio telescope is an onsite computer known as a correlator. Developed through a partnership with IBM and Cisco, the MWA’s correlator compares signals from each of the 2,048 antennae. Noise is random; real signals are correlated. By accepting only correlated signals, this step reduces the data to a manageable 1% of the initial deluge.

    The next phase takes place off-site. An 800 km optic fibre ferries the pre-filtered data from the desert to the Pawsey Supercomputing Centre in Perth. A mirror link also takes it to collaborators at the Massachusetts Institute of Technology in Boston, and Victoria University of Wellington in New Zealand, to be used by some 35 different science projects.

    Just as a human brain must process vast amounts of data into a meaningful representation of the world, these supercomputers turn the MWA radio wave signals into pictures of the universe. There are data from across different regions of the sky, and across tens of thousands of frequencies. It is sifted by setting windows to extract “cubes” of information. Like pixels on a screen, they provide an image of the universe.

    The MWA’s coarse resolution means its cubes can’t produce a sharp image. SKA, with its 100-fold greater sensitivity and 40-fold increase in resolution, will provide more cubes to show us what is actually there. But in order to do that, it must solve the data deluge problem.

    8
    The Pawsey Supercomputing Centre in Perth, transforms huge amounts of raw data into images of the universe. Pawsey Supercomputing Centre

    Scaling up to SKA

    The antenna design selected for SKA is not the MWA’s squat spider, but one that resembles a pine tree – the so-called log periodic design. Different rung lengths on the tree enable it to resonate in a wide range of frequencies – from 50 to 650 MHz. (MWA typically manages 80 to 300 MHz.) SKA will deploy 130,000 of them.

    But that won’t deliver the eponymous square kilometre of collecting area. The €650 million (about US$690 million) funding for phase 1 will only deliver four-tenths of that. Nevertheless, it should have the sensitivity to detect primordial galaxies across large patches of sky.

    9

    The first phase of SKA-low will churn out raw data at a daily rate greater than the world’s internet traffic; impossible to store, or for human minds to process in real time. Ingenious algorithms will be needed to sift valuable nuggets from the deluge.

    The University of Cambridge leads a consortium of 23 organisations, including Perth’s ICRAR, to develop new hardware and software systems for the task. One of ICRAR’s major software contributions goes by the name DALiuGE – an acronym for “data activated logical graph engine”. It’s also a bilingual play on the word deluge: “liu” is a Chinese character meaning “flow”.

    Last June, an ICRAR team successfully ran the prototype of DALiuGE on the second-most powerful supercomputer in the world, Tianhe-2, in Guangzhou, China. Next, the team hopes to test it on the most powerful, Sunway TaihuLight in Wuxi, eastern China.

    The computing challenges may be huge, but it’s not the first time the global community has taken on something so big. To solve CERN’s problem of distributed processing and information sharing, its researchers ended up developing the World Wide Web. “That changed our world forever,” Quinn says. “I suspect the SKA will do the same.”

    SKA’s rewards are already reaching beyond science into industry. Besides CISCO and IBM, other big-name collaborators on the project include British-Australian mining giant Rio Tinto, international gas and oil company Chevron, Amazon and Intel. All are highly attuned to new ways of solving their big data problems – whether it is crunching data to make images of oil, gas and mineral deposits below the ground, or finding patterns in vast databases.

    Construction in the middle of nowhere

    The computational challenges of the SKA are formidable; so too are those involved in building and rolling out the infrastructure in the middle of the Australian outback. It’s a perfect job for a former army tank officer.

    Tom Booler has been project manager for the MWA and part of the SKA-low team since 2011. His mission is to plan the construction and deployment of 130,000 antennas in the desert – absent a local workforce, with no construction equipment and no power grid. And that’s only the first phase of SKA-low. The second, slated for the mid-2020s pending funding, will see the number of antennas swell to about a million. The scale, cost and remoteness of the site make it one of the toughest science projects ever undertaken.

    Supplying power is a major hurdle. The MWA is powered by a 1.6 MW hybrid solar-diesel power station, parts of which must be shielded to stop the radio waves it creates from interfering with the telescope. Phase 1 of SKA-low will need 2.25 MW. Phase 2 will need the power supply of a small city.

    Extreme weather also has to be factored in. In 2015, nearby Milly Milly Station bore a year’s worth of rain in five months. While cattle grazers welcomed it, road closures disrupted plans at the observatory. Besides sudden downpours, Booler also has to reckon with temperatures soaring over 40 ºC in the summer months – and then there’s the desert death adder.

    But one thing the shire of Murchison has going for it – and a reason it won the bid for the SKA – is the quiet. Population density is extremely low – just 115 people spread over an area the size of the Netherlands. There are no mobile phone towers or radio and television transmitters. The shire is also hushed by regulations enforced by the Australian Communications and Media Authority.

    Within the observatory, every appliance gets stripped of wi-fi hardware before it arrives. The observatory control centre, which houses computers that crunch data from the existing telescopes, is the radio equivalent of an airlock, with radio-wave-proof double doors and no windows.

    Inside a radius of 70km around the observatory authorities can order mobile phones be turned off. Out to 260km emissions are regulated in key radio frequency ranges.

    The entire area is more than six times bigger than the US National Radio Quiet Zone, home to the Green Bank radio telescope and a population running into hundreds of thousands.

    The quiet zones do not extend to high altitudes, so planes communicating with air traffic control could present a problem. To tackle that issue, CSIRO researchers have begun to investigate ways to measure the interference and remove it from the telescope observations.

    Final stretch

    As difficult as building the SKA will be, coming up with the money to bankroll it is trickier. Negotiations with the 10 participating governments for the first phase have been underway since late 2015.

    But there’s a new sense of ease pervading the SKA community as it looks to an April 2017 sign-off on a binding treaty known as an International Government Organisation (IGO).

    Once signed, ministers of each country will have a year to ratify it. Once ratified, researchers are confident things should roll out smoothly. There is a strong precedent: CERN is governed by an IGO, with 22 member states. “It’s a well-tested model,” says Pearce, who previously worked on computing challenges for the LHC as part of a multinational collaboration.

    With SKA-low expected to come online in 2021, and be fully operational in 2024 astronomers are at last allowing themselves to get excited. “Until we can put a radio telescope on the moon, it will be the greatest advance in low-frequency radio astronomy,” says Elisabeth Mills, a radio astronomer at San José State University in California. “With such a great leap in technical capabilities, the most important advances from this telescope may be in areas we cannot even currently predict or imagine.”

    Back to the cosmic dawn

    We know something of the first few moments after the violent birth of our universe. A split second after the Big Bang, it was a tiny mushrooming fireball, 10 billion degrees hot and filled with a plasma of frenetic charged particles.

    Over the next 380,000 years, the expanding universe cooled. Charged particles – electrons and protons – lost enough of their youthful energy to bond with each other and form the first hydrogen atoms. In this more staid universe, light from the Big Bang could at last move in uninterrupted straight lines. As space continued to expand, the light waves stretched to the length of microwaves – which we see today as the cosmic microwave background.

    This much we know. The next episode remains a mystery.

    At 380,000 years old, the universe was a peaceful sea of hydrogen. A billion years later, most of it was gone. We know a small percentage snowballed under the influence of gravity to form stars and galaxies. But the vast intergalactic sea of hydrogen gas disappeared, reionised into a plasma of protons and electrons. The era is known as “the epoch of reionisation”.

    How did this happen? It turns out there are lots of theories, and they are almost completely unconstrained by data.

    Traces of dark matter laid down in the Big Bang, slightly denser than their surrounds, may have triggered the snowballing of hydrogen into stars. But why did the intergalactic hydrogen disappear?

    The leading theory is ultraviolet radiation from the first hot stars stripped the surrounding hydrogen of its electrons. But there is another contender: quasars. Quasars (quasi-stellar radio sources) are among the brightest and oldest objects in the universe. They are powered by black holes; the source of their light is the radiation emitted by accelerating gases as they are sucked towards the accretion disc. Quasars can be surprisingly ancient, appearing just 770 million years after the Big Bang.

    “It’s controversial, but one exciting possibility is that it was quasars that reionised the universe,” says astrophysicist Stuart Wyithe, at the University of Melbourne, who specialises in trying to recreate this unknown period of the history of the universe. The theory also suggests that massive black holes may have played a far greater role in shaping our Universe than previously thought.

    In Wyithe’s computer modelling, the ancient universe resembles Swiss cheese. The cheese is neutral hydrogen and the holes are where it has been eaten away, leaving an ionised plasma. Over a period of about 300 million years, the holes grow larger until, by about a billion years after the Big Bang, there’s almost no cheese left.

    SKA-low is designed to supply theorists like Wyithe with hard data. It will have the resolution and the wide angle to map the distribution of hydrogen in the early universe and trace how it changed over time. He will combine these images with those from the Hubble telescope to try and detect what’s at the centre of those cheesy holes: stars or quasars.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
  • richardmitnick 9:17 pm on December 14, 2016 Permalink | Reply
    Tags: , , , SKA, SKA passes key engineering milestone towards final design   

    From SKA: “SKA passes key engineering milestone towards final design” 

    SKA Square Kilometer Array

    SKA

    14 December 2016
    No writer credit

    The SKA has passed a key milestone in its engineering process with the positive conclusion of the System Preliminary Design Review (PDR). This review paves the way for the continuation of the engineering design work towards detailed design and Critical Design Review (CDR) before approval of construction.

    Last week at the SKA Headquarters, external experts in the management of large-scale projects from the European Space Agency, The US National Radio Astronomy Observatory, the international ALMA Observatory and the Italian National Institute for Nuclear Physics among others gathered to review and assess the maturity of the SKA’s system design. The system design is an engineering process that aims to define the architecture, components and interfaces of the SKA system (the telescope as a whole, from receiver to antenna to data transport, processing, storage and distribution) as per its requirements. The objectives of the system PDR were to ensure that the preliminary design of the SKA was mature enough and that the remaining gaps and risks in the design were identified to enable the project to start detailed design work.

    The reviewers approved the system design, noting the huge amount of work carried out so far by the SKA Office and engineering consortia, as well as the maturity of the architectural design.

    “We’re very pleased. Passing this important engineering milestone concludes what has been a busy year for the SKA on the engineering front, and everyone has worked hard to reach this point. This successful review will give confidence to industry and stakeholders that we are on the right path.” said Luca Stringhetti, the Project Engineer for SKA Organisation.

    See the full article here .

    Please help promote STEM in your local schools.
    STEM Icon

    Stem Education Coalition

    SKA Banner

    SKA CSIRO  Pathfinder Telescope
    SKA ASKAP Pathefinder Telescope

    SKA Meerkat telescope
    SKA Meerkat Telescope

    SKA Murchison Widefield Array
    SKA Murchison Wide Field Array

    About SKA

    The Square Kilometre Array will be the world’s largest and most sensitive radio telescope. The total collecting area will be approximately one square kilometre giving 50 times the sensitivity, and 10 000 times the survey speed, of the best current-day telescopes. The SKA will be built in Southern Africa and in Australia. Thousands of receptors will extend to distances of 3 000 km from the central regions. The SKA will address fundamental unanswered questions about our Universe including how the first stars and galaxies formed after the Big Bang, how dark energy is accelerating the expansion of the Universe, the role of magnetism in the cosmos, the nature of gravity, and the search for life beyond Earth. Construction of phase one of the SKA is scheduled to start in 2016. The SKA Organisation, with its headquarters at Jodrell Bank Observatory, near Manchester, UK, was established in December 2011 as a not-for-profit company in order to formalise relationships between the international partners and centralise the leadership of the project.

    The Square Kilometre Array (SKA) project is an international effort to build the world’s largest radio telescope, led by SKA Organisation. The SKA will conduct transformational science to improve our understanding of the Universe and the laws of fundamental physics, monitoring the sky in unprecedented detail and mapping it hundreds of times faster than any current facility.

    Already supported by 10 member countries – Australia, Canada, China, India, Italy, New Zealand, South Africa, Sweden, The Netherlands and the United Kingdom – SKA Organisation has brought together some of the world’s finest scientists, engineers and policy makers and more than 100 companies and research institutions across 20 countries in the design and development of the telescope. Construction of the SKA is set to start in 2018, with early science observations in 2020.

     
  • richardmitnick 3:29 pm on October 21, 2016 Permalink | Reply
    Tags: , , , SKA   

    From SKA: “Scientific synergies between the Athena observatory and the SKA telescope to be explored” 

    SKA Square Kilometer Array

    SKA

    ESA Athena spacecraft
    Athena

    Athena X-ray Observatory

    21 October 2016

    1
    The SKA-Athena Synergy Team (SAST) is working to identify and develop potential synergies between the SKA and the Athena X-ray observatory.

    ESA’s Advanced Telescope for High ENergy Astrophysics (Athena) and the Square Kilometre Array (SKA) will be key ingredients of the battery of next generation astronomical observatories in the late 2020s. These facilities will dominate the X-ray and radio windows respectively. Athena is set to study the hot and energetic Universe, specifically the assembly and evolution of hot baryons in large-scale structures and the influence of accretion into supermassive black holes on shaping galaxies. The SKA will also address a broad range of exciting science, from the observation of the very first stars and galaxies to the study of gravitational waves using pulsars and black holes, or the search for signatures of life in the galaxy.

    The Athena Science Study Team (ASST) and the SKA Organisation have agreed to undertake an exercise to identify and develop potential synergies between both large observatories. The Athena and SKA science objectives have areas in common, and combining data from the two facilities will result in a very exciting scientific added value. Themes where strong potential synergies have been preliminarily identified include galaxy clusters, AGN feedback, obscured AGN and transient phenomena.

    A SKA-Athena Synergy Team (SAST) has been appointed to explore and develop all foreseeable scientific synergies and, together with community experts, will produce the SKA-Athena Synergy White Paper. Four international leading figures, covering the relevant scientific areas and both wavelength domains, conform the SAST: Rossella Cassano (INAF/IRA, Chair), Chiara Ferrari (OCA), Rob Fender (Oxford) and Andrea Merloni (MPE). The SAST has kicked-off its activities on 27th September 2016.

    Community input will be invited through a dedicated Workshop organised by the SAST and hosted by the SKA Organisation headquarters in Jodrell Bank, UK during the first half of 2017. A list of specific topics to be covered in that Workshop will be issued by the SAST in the autumn of 2016, together with an open call for scientists willing to come to the Workshop and provide input for the SKA-Athena Synergy White Paper.

    After the Synergy Workshop, the SAST will prepare the SKA-Athena Synergy White Paper, which will be delivered to ESA’s ASST and the SKA Organisation around September 2017 and subsequently made public. “Athena‘s science output will be greatly enhanced when put together with observations from other large facilities in the late 2020s like SKA”, said Xavier Barcons, from ESA’s Athena Science Study Team. “Although it is often said that the whole is greater than the sum of the parts, this adage will certainly apply to the collaborative use of the Athena and SKA Observatories”, said Robert Braun, the SKA Science Director, “since the combination of these two extreme ends of the electromagnetic spectrum provides powerful astrophysical constraints.”

    The SKA-Athena Synergy exercise is supported by the Athena Community Office, the SKA Organisation, the Max-Planck Institut für Extraterrestriche Physik and the European Space Agency.

    See the full article here .

    Please help promote STEM in your local schools.
    STEM Icon

    Stem Education Coalition

    SKA Banner

    SKA CSIRO  Pathfinder Telescope
    SKA ASKAP Pathefinder Telescope

    SKA Meerkat telescope
    SKA Meerkat Telescope

    SKA Murchison Widefield Array
    SKA Murchison Wide Field Array

    About SKA

    The Square Kilometre Array will be the world’s largest and most sensitive radio telescope. The total collecting area will be approximately one square kilometre giving 50 times the sensitivity, and 10 000 times the survey speed, of the best current-day telescopes. The SKA will be built in Southern Africa and in Australia. Thousands of receptors will extend to distances of 3 000 km from the central regions. The SKA will address fundamental unanswered questions about our Universe including how the first stars and galaxies formed after the Big Bang, how dark energy is accelerating the expansion of the Universe, the role of magnetism in the cosmos, the nature of gravity, and the search for life beyond Earth. Construction of phase one of the SKA is scheduled to start in 2016. The SKA Organisation, with its headquarters at Jodrell Bank Observatory, near Manchester, UK, was established in December 2011 as a not-for-profit company in order to formalise relationships between the international partners and centralise the leadership of the project.

    The Square Kilometre Array (SKA) project is an international effort to build the world’s largest radio telescope, led by SKA Organisation. The SKA will conduct transformational science to improve our understanding of the Universe and the laws of fundamental physics, monitoring the sky in unprecedented detail and mapping it hundreds of times faster than any current facility.

    Already supported by 10 member countries – Australia, Canada, China, India, Italy, New Zealand, South Africa, Sweden, The Netherlands and the United Kingdom – SKA Organisation has brought together some of the world’s finest scientists, engineers and policy makers and more than 100 companies and research institutions across 20 countries in the design and development of the telescope. Construction of the SKA is set to start in 2018, with early science observations in 2020.

     
  • richardmitnick 1:32 pm on September 16, 2016 Permalink | Reply
    Tags: , , , HERA collaboration, , SKA,   

    From UC Berkeley and SKA: “Funding boost for SKA Precursor HERA telescope – What happened after the lights came on in the universe?” 

    UC Berkeley

    UC Berkeley

    SKA Square Kilometer Array

    SKA

    From SKA:
    Friday 21 September 2016, SKA Global Headquarters, UK – The Hydrogen Epoch of Reionisation Array (HERA) has been awarded international funding with a $9.5 million investment to expand its capabilities, as announced on Wednesday 14th September by the US National Science Foundation.

    1
    Image of the [beginnings of] HERA telescope at the Losberg Site in the Karoo desert. Credit: Danny Jacobs

    HERA, which was recently granted the status of SKA precursor telescope by SKA Organisation, currently has 19, 14-metre radio dishes at the SKA South Africa Losberg site near Carnarvon. With this fresh injection of $9.5 million, this will allow the array to expand to 220 radio dishes by 2018.

    HERA is an experiment focused on one science goal – detecting the Epoch of Reionization signal – and is not a general facility. As part of this effort, HERA is developing techniques, algorithms, calibration and processing pipelines and hardware optimised towards the detection of the power spectrum of the EOR, all of which will benefit SKA in designing and eventually operating the SKA-low telescope to be based in Australia.

    From UC Berkeley:

    September 14, 2016
    Robert Sanders

    An experiment to explore the aftermath of cosmic dawn, when stars and galaxies first lit up the universe, has received nearly $10 million in funding from the National Science Foundation to expand its detector array in South Africa.

    2
    The HERA collaboration expects eventually to expand to 330 radio dishes in the core array, each pointed straight up to measure radiation originally emitted some 13 billion years ago. Twenty outrigger dishes (not shown) are also planned, bringing the array up to 350 dishes total.

    The experiment, an international collaboration called the Hydrogen Epoch of Reionization Array, or HERA, currently has 19 14-meter (42-foot) radio dishes aimed at the southern sky near Carnarvon, South Africa, and will soon up that to 37. The $9.5 million in new funding will allow the array to expand to 240 radio dishes by 2018.

    Led by UC Berkeley, HERA will explore the billion-year period after hydrogen gas collapsed into the first stars, perhaps 100 million years after the Big Bang, through the ignition of stars and galaxies throughout the universe. These first brilliant objects flooded the universe with ultraviolet light that split or ionized all the hydrogen atoms between galaxies into protons and electrons to create the universe we see today.

    “The first galaxies lit up and started ionizing bubbles of gas around them, and soon these bubbles started percolating and intersecting and making bigger and bigger bubbles,“ said Aaron Parsons, a UC Berkeley associate professor of astronomy and principal investigator for HERA. “Eventually, they all intersected and you got this über bubble, leaving the universe as we observe it today: Between galaxies the gas is essentially all ionized.“

    That’s the theory, anyway. HERA hopes for the first time to observe this key cosmic milestone and then map the evolution of reionization to about 1 billion years after the Big Bang.

    “We have leaned a ton about the cosmology of our universe from studies of the cosmic microwave background, but those experiments are observing just the thin shell of light that was emitted from a bunch of protons and electrons that finally combined into neutral hydrogen 380,000 years after the Big Bang,“ he said. “We know from these experiments that the universe started out neutral, and we know that it ended ionized, and we are trying to map out how it transitioned between those two.“

    “Before the cosmic dawn, the universe glowed from the cosmic microwave background radiation, but there weren’t stars lighting up the universe,“ said David DeBoer, a research astronomer in UC Berkeley’s Radio Astronomy Laboratory. “At some point the neutral hydrogen seeded the stars and black holes and galaxies that relit the universe and led to the epoch of reionization.“

    3
    A 13.8-billion-year cosmic timeline indicates the era shortly after the Big Bang observed by the Planck satellite, the era of the first stars and galaxies observed by HERA and the era of galaxy evolution to be observed by NASA’s future James Webb Space Telescope. (HERA image)

    The HERA array, which could eventually expand to 350 telescopes, consists of radio dishes staring fixedly upwards, measuring radiation originally emitted at a wavelength of 21 centimeters – the hyperfine transition in the hydrogen atom – that has been red-shifted by a factor of 10 or more since it was emitted some 13 billion years ago. The researchers hope to detect the boundaries between bubbles of ionized hydrogen – invisible to HERA – and the surrounding neutral or atomic hydrogen.

    By tuning the receiver to different wavelengths, they can map the bubble boundaries at different distances or redshifts to visualize the evolution of the bubbles over time.

    “HERA can also tell us a lot about how galaxies form,“ Parsons said. “Galaxies are very complex organisms that feed back on themselves, regulating their own star formation and the gas that falls into them, and we don’t really understand how they live, especially at this early time when flowing hydrogen gas ends up as complex structures with spiral arms and black holes in the middle. The epoch of reionization is a bridge between the cosmology that we can theoretically calculate from first principles and the astrophysics we observe today and try to understand.“

    UC Berkeley’s partners in HERA are the University of Washington, UCLA, Arizona State University, the National Radio Astronomical Observatory, the University of Pennsylvania, the Massachusetts Institute of Technology, Brown University, the University of Cambridge in the UK, the Square Kilometer Array in South Africa and the Scuola Normale Superiore in Pisa, Italy.

    Other collaborators are the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, the University of KwaZulu Natal, the University of Western Cape and Rhodes University, all in South Africa, and California State Polytechnic University in Pomona.

    “Astronomers want to know what happened to the universe after it emerged from its so-called ‘dark ages’,” said Rich Barvainis, director of the National Science Foundation program that funds HERA. “HERA will help us answer that question, not by studying the primordial stars and galaxies themselves, but rather by studying how these objects changed the nature of intergalactic space.”

    Searching for a firefly on a searchlight

    The key to detecting these percolating bubbles of ionized gas from the epoch of reionization is a receiver that can detect radio signals from neutral hydrogen a million times fainter than nearby radio noise.

    “The foreground noise, mostly synchrotron emission from electrons spiraling in magnetic fields in our own galaxy, is about a million times stronger than the signal,“ DeBoer said. “This is a real problem, because it’s like looking for a firefly in front of an incredibly powerful searchlight. We are trying to see the firefly and filter out the searchlight.“

    Previous experiments, such as the UC Berkeley-led Precision Array Probing the Epoch of Reionization (PAPER) in South Africa and the Murchison Widefield Array (MWA) in Australia, have not been sensitive enough to detect this signal, but with larger dishes and better signal processing, HERA should do the trick.

    “HERA is a unique, next-generation instrument building on the heritage of PAPER,“ said Parsons, who helped build PAPER a decade ago when he was a graduate student working with the late UC Berkeley astronomer Donald Backer. “It is on the same site as PAPER, we are using a lot of the same equipment, but importantly we have brought together a lot more collaborators, including a lot of the U.S. team that has been working with MWA.“

    The strategy is to build a hexagonal array of radio dishes that minimizes the noise, such as radio reflections in the dishes and wires, that would obscure the signal. A supercomputer’s worth of field programmable gate arrays will cross-correlate the signals from the antennas to finely map a 10-degree swath of southern sky centered at minus-30 degrees latitude. Using a technique adopted from PAPER, they will employ this computer processing power to eliminate the slowly varying noise across the wavelength spectrum – 150-350 centimeters – to reveal the rapidly varying signal from neutral hydrogen as they tune across the radio spectrum.

    Astronomers have already discovered hints of reionization, Parsons said. Measurements of the polarization of the cosmic microwave background radiation show that some of the photons emitted at that early time in the universe have been scattered by intervening electrons possibly created by the first stars and galaxies. And galaxy surveys have turned up some very distant galaxies that show attenuation by intervening intergalactic neutral hydrogen, perhaps the last bit remaining before reionization was complete.

    “We have an indication that reionization should have happened, and we are getting hints of when it might have ended, but we don’t have anything telling us what is going on during it.,“ Parsons added. “That is what we hope to learn with HERA, the actual step-by-step process of how reionization happened.“

    Once astronomers know the reionization process, they can calculate the scattering of radiation from the era of recombination – the cosmic background radiation, or CMB – and remove some of the error that makes it hard to detect the gravitational waves produced by inflation shortly after the Big Bang.

    “There is a lot of cosmology you can do with HERA,“ Parsons said. “We have learned so much from the thin shell of the CMB, but here we will be looking at a full three-dimensional space. Something like 80 percent of the observable universe can be mapped using the 21-centimeter line, so this opens up the next generation of cosmology.“

    Parsons and DeBoer compare HERA to the first experiment to detect the cosmic microwave background radiation, the Cosmic Background Explorer, which achieved its goal in 1992 and won for its leaders – George Smoot of UC Berkeley and Lawrence Berkeley National Laboratory, and John Mather of NASA – the 2006 Nobel Prize in Physics.

    “Ultimately, the goal is to get to the point were we are actually making images, just like the CMB images we have seen,“ DeBoer said. “But that is really, really hard, and we need to learn a fair bit about what we are looking for and the instruments we need to get there. We hope that what we develop will allow the Square Kilometre Array or another big project to actually make these images and get much more science from this pivotal epoch in our cosmic history.“

    See the full SKA article here .
    See the UC Berkeley press release here .
    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Founded in the wake of the gold rush by leaders of the newly established 31st state, the University of California’s flagship campus at Berkeley has become one of the preeminent universities in the world. Its early guiding lights, charged with providing education (both “practical” and “classical”) for the state’s people, gradually established a distinguished faculty (with 22 Nobel laureates to date), a stellar research library, and more than 350 academic programs.

    UC Berkeley Seal

     
  • richardmitnick 6:39 am on July 23, 2016 Permalink | Reply
    Tags: , , SKA, Statement from the Board of Directors of SKA Organisation on the outcome of the UK’s EU referendum   

    From SKA: “Statement from the Board of Directors of SKA Organisation on the outcome of the UK’s EU referendum” 

    SKA Square Kilometer Array

    SKA

    The Board of Directors of the Square Kilometre Array (SKA) Organisation recently met at the SKA Headquarters at Jodrell Bank near Manchester in the UK for its 21st Board Meeting. This is the first time the Board has met since the result of the UK’s EU referendum held a few weeks ago and the consequent decision to leave the EU.

    Dr Adam Baker from the Science and Research Directorate of the UK Department for Business, Energy and Industrial Strategy (BEIS) reaffirmed the strong commitment of the country to the SKA project stating that “with respect to the Square Kilometre Array itself, the UK’s position has not changed. We are still deeply committed to the SKA and its success. The Minister for Universities and Science, Jo Johnson re-iterated the UK’s support for world class research and innovation at a speech to the Wellcome Trust on 30th June. This included specific reference to the SKA.”

    All SKA members’ representatives in the Board took note of the positive statement from the UK, keeping the project on the right track ahead of the construction in 2018 in particular the pursuing of international negotiations to establish the SKA as an Inter-Governmental Organisation or IGO –similar to CERN or ITER.

    All members of the Board, the Director-General of SKA Organisation and the Chair of the Board also took this opportunity to express their pride in the international nature of the SKA project and emphasised the essential contribution of the highly qualified personnel from over 14 different nationalities working at the SKA Headquarters in the UK as well as around the world to deliver the project.

    “The recruitment of talent from around the world is what makes a project such as SKA possible and all members of the Board remain fully committed to ensuring the SKA project can attract and recruit the best and most qualified staff regardless of their origin,” concluded Giovanni Bignami, Chair of the SKA Board.

    See the full article here .

    Please help promote STEM in your local schools.
    STEM Icon

    Stem Education Coalition

    SKA Banner

    SKA CSIRO  Pathfinder Telescope
    SKA ASKAP Pathefinder Telescope

    SKA Meerkat telescope
    SKA Meerkat Telescope

    SKA Murchison Widefield Array
    SKA Murchison Wide Field Array

    About SKA

    The Square Kilometre Array will be the world’s largest and most sensitive radio telescope. The total collecting area will be approximately one square kilometre giving 50 times the sensitivity, and 10 000 times the survey speed, of the best current-day telescopes. The SKA will be built in Southern Africa and in Australia. Thousands of receptors will extend to distances of 3 000 km from the central regions. The SKA will address fundamental unanswered questions about our Universe including how the first stars and galaxies formed after the Big Bang, how dark energy is accelerating the expansion of the Universe, the role of magnetism in the cosmos, the nature of gravity, and the search for life beyond Earth. Construction of phase one of the SKA is scheduled to start in 2016. The SKA Organisation, with its headquarters at Jodrell Bank Observatory, near Manchester, UK, was established in December 2011 as a not-for-profit company in order to formalise relationships between the international partners and centralise the leadership of the project.

    The Square Kilometre Array (SKA) project is an international effort to build the world’s largest radio telescope, led by SKA Organisation. The SKA will conduct transformational science to improve our understanding of the Universe and the laws of fundamental physics, monitoring the sky in unprecedented detail and mapping it hundreds of times faster than any current facility.

    Already supported by 10 member countries – Australia, Canada, China, India, Italy, New Zealand, South Africa, Sweden, The Netherlands and the United Kingdom – SKA Organisation has brought together some of the world’s finest scientists, engineers and policy makers and more than 100 companies and research institutions across 20 countries in the design and development of the telescope. Construction of the SKA is set to start in 2018, with early science observations in 2020.

     
c
Compose new post
j
Next post/Next comment
k
Previous post/Previous comment
r
Reply
e
Edit
o
Show/Hide comments
t
Go to top
l
Go to login
h
Show/Hide help
shift + esc
Cancel
%d bloggers like this: