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  • richardmitnick 9:15 am on July 4, 2018 Permalink | Reply
    Tags: , , , , Japan’s VERA telescope granted SKA pathfinder status, , SKA - Square Kilometre Array, The VLBI Exploration of Radio Astrometry (VERA) telescope   

    From SKA: “Japan’s VERA telescope granted SKA pathfinder status” 


    From SKA

    3 July 2018

    The VLBI Exploration of Radio Astrometry (VERA) telescope, operated by the National Astronomical Observatory of Japan, has been officially designated as an SKA pathfinder.

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    Mizusawa station is one of four across Japan that make up the VERA telescope. (Credit: NAOJ)

    In operation since 2003, VERA uses Very Long Baseline Interferometry (VLBI) to explore the three-dimensional structure of the Milky Way based on high-precision astrometry of Galactic maser sources. It comprises four Cassegrain antennas each measuring 20 metres in diameter.

    VERA joins more than a dozen pathfinder facilities around the globe which are contributing to SKA-related technology and science. Pathfinder telescopes provide valuable information to teams working on the design of the SKA, but unlike precursors they are not located at SKA sites.

    “VERA mainly performs K (22 GHz) and Q (43 GHz) band VLBI observations. Therefore, science cases at such high frequencies will be intensively developed with VERA,” said Prof. Mareki Honma, Director of the Mizusawa VLBI Observatory, which operates the telescope as part of NAOJ. “In future, VERA could enhance SKA VLBI capabilities, providing SKA-mid instrument with the intercontinental, longest baseline. Such a potential will also improve the value of the SKA.”

    SKA-mid, an array of almost 200 dishes in its first phase, will be hosted in South Africa’s Karoo region, incorporating the existing 64-dish MeerKAT precursor telescope.

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

    It will be engaged in exploring many exciting areas of science, including gravitational waves, pulsars, and the search for signs of life in the galaxy. A later expansion would see SKA baselines extended across the African continent.

    While two of the four VERA antennas are on the Japanese mainland, the other two are located on the outlying Ishigaki and Ogasawara islands. NAOJ notes that the difficulty of accessing these sites can provide important lessons about Telescope Management for the SKA, where teams will face similar issues at remote sites in Australia and South Africa.

    “NAOJ and the Mizusawa VLBI Observatory have skills in all aspects of VLBI science and its techniques. In particular they bring expertise in high-frequency (for SKA) receiver systems, ADCs and VLBI backends that is of great interest to the SKA,” said Prof. Phil Diamond, SKAO Director-General. Analogue to digital convertors (ADCs) convert signals so that they can be transmitted over optical fibre, an important component for the SKA.

    Prof. Diamond added: “We look forward to further collaborations with our Japanese colleagues through VERA and we are hopeful that this will contribute to advancing the SKA case in Japan.”

    Read more about VERA on the project’s website, and learn about other SKA pathfinders and precursors around the world here.

    See the full article here .


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    SKA ASKAP Pathefinder Telescope

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

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


    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.

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  • richardmitnick 1:00 pm on December 18, 2017 Permalink | Reply
    Tags: AAVS1-Aperture Array Verification System, , , , , Designing the SKA Telescopes – From lab to Outback: the story of AAVS1 so far, MRO-Murchison Radio-astronomy Observatory, , SKA - Square Kilometre Array, SKA1-low   

    From SKA: “Designing the SKA Telescopes – From lab to Outback: the story of AAVS1 so far” 


    SKA

    18 December 2017

    1
    Designing the SKA telescopes – From lab to Outback: the story of AAVS1 so far. Credit: ICRAR

    It is an understatement to say that designing and building a world-class scientific instrument comes with its challenges. The Aperture Array Verification System (AAVS1) is one of the major milestones in the journey towards delivering the final design for SKA1-low, the Australian arm of the first phase of the SKA telescope, that will eventually consist of 130,000 antennas observing low frequency signals emanating from the cosmos. The team delivering this project recently reported on the successful roll-out of a station made up of 256 antenna prototypes at the Murchison Radio-astronomy Observatory (MRO), located in Western Australia.

    “The journey leading up to the deployment and installation of a full antenna station has been a fantastic experience and a steep learning curve for everyone involved”, said the Netherlands Institute for Radio Astronomy (ASTRON) engineer Pieter Benthem, AAVS1 Project Manager. “It’s one thing to design, simulate and test the antennas and systems for AAVS1 inside a computer and a totally different thing to deal with the practicalities and logistical complexities of deploying the array on a remote site, on the other side of the planet.”

    Overcoming several technical and logistics issues, the AAVS1 team completed the main station of AAVS1 during their most recent site trip in early November. Previous site trips in August and March showed the dedication of the team.

    “Despite being separated from home and family, the team powered on and got a tremendous amount of work done”, added Jader Monari, engineer from the Italian National Institute for Astrophysics (INAF) and AAVS1 Italian group leader. “This fruitful international collaboration showcases much more than just getting ready for the Critical Design Review (CDR) in a few months time. Working at the MRO was quite an experience for many of us coming from the other side of the globe, and the harsh conditions we had to cope with made us bond quite rapidly, with a very positive impact on the team’s performance. Every day, back at Wooleen or Boolardy Station [where the team lodged], we were holding what we called “family meetings”, where we would share joys or frustrations of the day, and discuss the next day’s activities in a professional yet very friendly atmosphere.”

    The AAVS1 project is a key deliverable for the Low Frequency Aperture Array (LFAA) consortium, bringing together a team of experts from Australia, the United Kingdom, Malta, the Netherlands and Italy. LFAA, led by ASTRON, is one of 12 consortia in charge of designing the various elements for the SKA telescope.

    ”Getting the actual designers to the MRO has been a great opportunity to allow them to assemble, test and deploy their design”, added Pieter Benthem. “Several lessons were learned across the board from deployment to commissioning, including details on local materials to be used and feedback towards the next design iteration; all valuable input that will inform the design process ahead of the CDR and help prepare for SKA1-low.”

    “This is really one of those projects where the whole is far greater than the sum of its parts”, commented Philip Gibbs, LFAA Project Manager at the SKA Organisation. “Every single individual has brought a great deal of expertise to the deployment of the full station. To name but a few examples of this truly international team, the design of the AAVS1 antenna prototypes was led by the University of Cambridge in the UK; procurement of fibre optics and circuit board design was done by INAF in Italy; both INAF and ASTRON purchased and produced the digitisers boards, gathering important know-how on different production techniques on a single printed circuit board design; our Maltese colleagues along with a team at Oxford University applied their expertise in the firmware, monitor and control software of the antennas; and of course our Australian colleagues from ICRAR and Curtin University provided all logistical support to bring this prototype to life in the West Australian desert drawing on their extensive expertise for constructing and deploying radio telescopes in remote regions. ICRAR and Curtin engineers also designed the intra-station power and fibre distribution system, without which the AAVS1 antennas would have no power and the signals received would not be able to leave the station. All of this being overseen and managed by ASTRON in the Netherlands—so indeed, a truly global enterprise.”

    The AAVS1 test platform is located at the Murchison Radio-astronomy Observatory (MRO), 800 km north-east of Perth, Western Australia, is home not only to the future SKA1-low telescope but also to the precursor facilities, the Australian SKA Pathfinder (ASKAP) telescope—a 36-dish instrument— and the Murchison Widefield Array (MWA) —comprising 2,048 dipole antennas. The MRO is owned and operated by CSIRO, Australia’s national science agency, which also designed and operates ASKAP. CSIRO’s engineers, responsible for ASKAP operations, have also supported the LFAA team through deployment according to ICRAR’s David Emrich. “CSIRO people are always willing to lend support, tools and in-kind assistance and the engineers, along with the site support staff, have established a really collaborative culture. It makes a difference in this harsh and extremely remote location,” he said.

    3
    Credits: left photo: CSIRO; right photo: ICRAR

    Both of these telescopes have been instrumental in testing and further developing the technologies for the SKA however, the low-frequency MWA telescope provided test and development precedents for AAVS1. Online since mid-2013, MWA receives signals from the early Universe within the bandwidth of 80 to 300 MHz. Through its years of operations and refining of techniques, the MWA has pioneered methods for AAVS1, such as adjusting for the distorting effects of the ionosphere above the Murchison, and also refining the method to reduce the noise inherent in the system. ICRAR also planned the deployment of the LFAA which at the start of pre-construction in 2013 was considered the critical risk to realising SKA1-low. AAVS1 has been informed by the development of the LFAA deployment plan.

    4
    Credit: ICRAR

    However, deploying the AAVS1 prototype has been one of several challenges faced by the LFAA consortium team. Drawing from a decade of engineering work worldwide in low-frequency radio astronomy, the team has learnt from MWA, LOFAR and others operating in the same radio frequency regime and has developed improved antenna designs for SKA1-low. These designs, known as the SKALA prototype design, are a log periodic design with various different rung lengths which enable sensitivity to a wide range of frequencies —which operate from 50 to 650 MHz. The continuous evolution of the SKALA prototype has led to the proposed SKALA4 design, an evolution of SKALA2 which has been deployed on site as part of the AAVS1 project.

    An international panel of experts tasked with evaluating multiple performance and design metrics of various proposed antenna designs, considers the SKALA4 antenna to be the best option for the LFAA Critical Design Review (CDR) in July 2018. A comprehensive report on this design will be presented for the Review in July.

    5
    Credit: ICRAR

    About the LFAA Consortium

    The “Low-Frequency Aperture Array” (LFAA) element is the set of antennas, on-board amplifiers and local processing required for the Aperture Array telescope of the SKA.

    The LFAA consortium is led by the Netherlands Institute for Radio Astronomy (ASTRON) and includes the International Centre for Radio Astronomy Research (ICRAR), Australia; the Key Lab of Aperture Array and Space Application (KLAASA), China; the National Institute for Astrophysics (INAF), Italy; the University of Malta; the Joint Institute for VLBI in Europe (JIVE), the Netherlands; the University of Cambridge, UK; the University of Manchester, UK; the University of Oxford, UK; the Science and Technology Facilities Council (STFC), UK; Observatoire de la Cote d’Azur, France; and Station de Radioastronomie de Nançay, France.

    See the full article here .

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    SKA ASKAP Pathefinder Telescope

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


    SKA Meerkat Telescope

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


    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 4:02 pm on November 14, 2017 Permalink | Reply
    Tags: , , , , , , , SKA - Square Kilometre Array   

    From Dunlap: “Major Upgrade Increases Power of Radio Telescope to Probe the Universe 

    Dunlap Institute bloc
    Dunlap Institute for Astronomy and Astrophysics

    Nov 14, 2017
    CONTACT INFORMATION:

    Prof. Bryan Gaensler, Director
    Dunlap Institute for Astronomy & Astrophysics
    University of Toronto
    416-978-6223
    bgaensler@dunlap.utoronto.ca
    http://www.dunlap.utoronto.ca/prof-bryan-gaensler

    Chris Sasaki
    Communications Coordinator | Press Officer
    Dunlap Institute for Astronomy & Astrophysics
    University of Toronto
    416-978-6613
    csasaki@dunlap.utoronto.ca

    SKA Murchison Widefield Array

    The Murchison Widefield Array (MWA), a radio telescope in the outback of Western Australia, has completed a planned major upgrade, making it ten times more sensitive and doubling its ability to resolve detail.

    Astronomers are using the MWA to make a detailed map of the entire southern radio sky. They are also using it to make observations of hydrogen gas from an epoch of the Universe when the first stars and galaxies were forming; study the Milky Way Galaxy’s magnetic field; and investigate radio sources like pulsars, X-ray binary stars and neutron stars.

    “The original MWA opened our eyes to a new view of the radio sky,” says Prof. Bryan Gaensler, Director of the Dunlap Institute for Astronomy & Astrophysics, and Canadian representative on the MWA Board of Partners. “This upgrade greatly sharpens that view, and allows us to study in detail the new objects that the MWA discovered earlier.”

    The MWA is one of four precursor telescopes for the Square Kilometre Array (SKA) which, when completed in the mid-2020s, will be the largest radio telescope ever built.

    SKA Square Kilometer Array

    It will have a total collecting area of a square kilometre, with antennas located in Australia and South Africa. SKA will be a ground-breaking instrument which astronomers will use to conduct new tests of General Relativity, observe the very first stars and galaxies, and investigate dark energy and cosmic magnetism.

    The MWA upgrade marks the completion of Phase Two in its development with the addition of 128 new antenna stations to the existing 128. Each station comprises 16 antennas for a total of over four thousand antennas arranged within an area with a diameter of roughly six kilometres.

    The array is located at the Murchison Radio-astronomy Observatory in Western Australia and is operated by an international consortium led by Curtin University and which includes partners from Australia, India, New Zealand, China, the United States and Canada. The University of Toronto officially joined the consortium in June 2016

    “The MWA is not only an amazing scientific facility in its own right,” says Gaensler, “but it is a vital stepping stone and test-bed for our even more ambitious plans for the SKA.”

    Additional notes:
    1) The Phase Two expansion of the MWA was partly funded by a $1 million grant as part of the Australian Research Council (ARC) Linkage Infrastructure, Equipment and Facilities (LIEF) scheme. A further $1.2 million has been provided by partner institutions.

    See the full article here .

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    Dunlap Institute campus

    The Dunlap Institute is committed to sharing astronomical discovery with the public. Through lectures, the web, social and new media, an interactive planetarium, and major events like the Toronto Science Festival, we are helping to answer the public’s questions about the Universe.
    Our work is greatly enhanced through collaborations with the Department of Astronomy & Astrophysics, Canadian Institute for Theoretical Astrophysics, David Dunlap Observatory, Ontario Science Centre, Royal Astronomical Society of Canada, the Toronto Public Library, and many other partners.

     
  • richardmitnick 1:49 pm on August 1, 2017 Permalink | Reply
    Tags: , , , , , SKA - Square Kilometre Array, ,   

    From Symmetry: “Tuning in for science” 

    Symmetry Mag

    Symmetry

    08/01/17
    By Mike Perricone

    1
    Square Kilometer Array

    The sprawling Square Kilometer Array radio telescope hunts signals from one of the quietest places on earth.

    SKA South Africa

    When you think of radios, you probably think of noise. But the primary requirement for building the world’s largest radio telescope is keeping things almost perfectly quiet.

    Radio signals are constantly streaming to Earth from a variety of sources in outer space. Radio telescopes are powerful instruments that can peer into the cosmos—through clouds and dust—to identify those signals, picking them up like a signal from a radio station. To do it, they need to be relatively free from interference emitted by cell phones, TVs, radios and their kin.

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

    That’s one reason the Square Kilometer Array is under construction in the Great Karoo, 400,000 square kilometers of arid, sparsely populated South African plain, along with a component in the Outback of Western Australia. The Great Karoo is also a prime location because of its high altitude—radio waves can be absorbed by atmospheric moisture at lower altitudes. SKA currently covers some 1320 square kilometers of the landscape.

    Even in the Great Karoo, scientists need careful filtering of environmental noise. Effects from different levels of radio frequency interference (RFI) can range from “blinding” to actually damaging the instruments. Through South Africa’s Astronomy Geographic Advantage Act, SKA is working toward “radio protection,” which would dedicate segments of the bandwidth for radio astronomy while accommodating other private and commercial RF service requirements in the region.

    “Interference affects observational data and makes it hard and expensive to remove or filter out the introduced noise,” says Bernard Duah Asabere, Chief Scientist of the Ghana team of the African Very Long Baseline Interferometry Network (African VLBI Network, or AVN), one of the SKA collaboration groups in eight other African nations participating in the project.

    2
    The Ghanaian and South African governments on Thursday announced the combination of ‘first light’ science observations, which confirm the successful conversion of the Ghana communications antenna from a redundant telecoms instrument into a functioning Very Long Baseline Interferometry (VLBI) radio telescope.

    Ghana is the first partner country of the African Very Large Baseline Interferometer (VLBI) Network (AVN) to complete the conversion of a communications antenna into a functioning radio telescope.

    SKA “will tackle some of the fundamental questions of our time, ranging from the birth of the universe to the origins of life,” says SKA Director-General Philip Diamond. Among the targets: dark energy, Einstein’s theory of gravity and gravitational waves, and the prevalence of the molecular building blocks of life across the cosmos.

    SKA-South Africa can detect radio spectrum frequencies from 350 megahertz to 14 gigahertz. Its partner Australian component will observe the lower-frequency scale, from 50 to 350 megahertz. Visible light, for comparison, has frequencies ranging from 400 to 800 million megahertz. SKA scientists will process radiofrequency waves to form a picture of their source.

    A precursor instrument to SKA called MeerKat (named for the squirrel-sized critters indigenous to the area), is under construction in the Karoo.

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

    This array of 16 dishes in South Africa achieved first light on June 19, 2016. MeerKAT focused on 0.01 percent of the sky for 7.5 hours and saw 1300 galaxies—nearly double the number previously known in that segment of the cosmos.

    Since then, MeerKAT met another milestone with 32 integrated antennas. MeerKat will also reach its full array of 64 dishes early next year, making it one of the world’s premier radio telescopes. MeerKAT will eventually be integrated into SKA Phase 1, where an additional 133 dishes will be built. That will bring the total number of antennas for SKA Phase I in South Africa to 197 by 2023. So far, 32 dishes are fully integrated and are being commissioned for science operations.

    On completion of SKA 2 by 2030, the detection area of the receiver dishes will exceed 1 square kilometer, or about 11,000 square feet. Its huge size will make it 50 times more sensitive than any other radio telescope. It is expected to operate for 50 years.

    SKA is managed by a 10-nation consortium, including the UK, China, India and Australia as well as South Africa, and receives support from another 10 countries, including the US. The project is headquartered at Jodrell Bank Observatory in the UK.

    The full SKA will use radio dishes across Africa and Australia, and collaboration members say it will have a farther reach and more detailed images than any existing radio telescope.

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

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

    In preparation for the SKA, South Africa and its partner countries developed AVN to establish a network of radiotelescopes across the African continent. One of its projects is the refurbishing of redundant 30-meter-class antennas, or building new ones across the partner countries, to operate as networked radio telescopes.

    4
    Hartebeesthoek Radio Astronomy Observatory in Gauteng.

    The first project of its kind is the AVN Ghana project, where an idle 32-meter diameter dish has been refurbished and revamped with a dual receiver system at 5 and 6.7 gigahertz central frequencies for use as a radio telescope. The dish was previously owned and operated by the government and the company Vodafone Ghana as a telecommunications facility. Now it will explore celestial objects such as extragalactic nebulae, pulsars and other RF sources in space, such as molecular clouds, called masers.

    Asabere’s group will be able to tap into areas of SKA’s enormous database (several supercomputers’ worth) over the Internet. So will groups in Botswana, Kenya, Madagascar, Mauritius, Mozambique, Namibia and Zambia. SKA is also offering extensive outreach in participating countries and has already awarded 931 scholarships, fellowships and grants.

    Other efforts in Ghana include introducing astronomy in the school curricula, training students in astronomy and related technologies, doing outreach in schools and universities, receiving visiting students at the telescope site and hosting programs such as the West African International Summer School for Young Astronomers taking place this week.

    Asabere, who achieved his advanced degrees in Sweden (Chalmers University of Technology) and South Africa (University of Johannesburg), would like to see more students trained in Ghana, and would like get more researchers on board. He also hopes for the construction of the needed infrastructure, more local and foreign partnerships and strong governmental backing.

    “I would like the opportunity to practice my profession on my own soil,” he says.

    That day might not be far beyond the horizon. The Leverhulme-Royal Society Trust and Newton Fund in the UK are co-funding extensive human capital development programs in the SKA-AVN partner countries. A seven-member Ghanaian team, for example, has undergone training in South Africa and has been instructed in all aspects of the project, including the operation of the telescope.

    Several PhD students and one MSc student from Ghana have received SKA-SA grants to pursue further education in astronomy and engineering. The Royal Society has awarded funding in collaboration with Leeds University to train two PhDs and 60 young aspiring scientists in the field of astrophysics.

    Based on the success of the Leverhulme-Royal Society program, a joint UK-South Africa Newton Fund intervention (DARA—the Development in Africa with Radio Astronomy) has since been initiated in other partner countries to grow high technology skills that could lead to broader economic development in Africa.

    As SKA seeks answers to complex questions over the next five decades, there should be plenty of opportunities for science throughout the Southern Hemisphere. Though it lives in one of the quietest places, SKA hopes to be heard loud and clear.

    See the full article here .

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    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 12:51 pm on May 27, 2017 Permalink | Reply
    Tags: , , , , Bubbles from reionization at the cosmic dawn, , , SKA - Square Kilometre Array   

    From astrobites: “Bubbles from reionization at the cosmic dawn” 

    Astrobites bloc

    Astrobites

    Title: Dark-ages reionization & galaxy formation simulation XII: Bubbles at dawn
    Authors: Paul Geil, Simon Mutch, Gregory Poole, Alan Duffy, Andrei Mesinger, and Stuart Wyithe
    First Author’s Institution: University of Melbourne, Parkville, Victoria, Australia

    Status: Submitted to MNRAS, open access

    The early universe encompasses many scarcely understood phenomena both cosmological and astrophysical that we hope to begin exploring. This can be made possible by looking at the highly redshifted 21cm emission (see here for why this emission happens) from neutral hydrogen which puts these observations from the cosmic dawn relevant to today’s astrobite into the radio frequency range of 100-140 MHz. But this signal is notoriously faint, and requires some of the most sensitive instruments ever designed to observe it. Currently this is an emerging field where most of the instruments with the necessary sensitivity are only now entering the development stage. This certainly won’t stop us from understanding the potential pitfalls we may encounter along the way in measuring the early universe. We can of course anticipate how well we can detect this signal through simulations of the 21cm emission and our next generation radio telescopes.

    Cosmic Dawn and Galactic Reionization Bubbles

    When the first galaxies began to form they also began to emit UV radiation. This UV radiation reionized the surrounding neutral hydrogen, which means that it can no longer emit the 21cm emission. From our perspective when observing this we see large spherical holes (bubbles) begin to form over time, making a ‘Swiss cheese’-like effect at the largest scales. To make up for a lack of bubble observations, simulations of bubble formation from the Dark ages Reionization & Galaxy Formation Simulation (DRAGONS) (for an example see Fig. 1) were created.

    2
    Fig 1: Example of two galaxies with similar luminosities and solar mass from the DRAGON simulation. The progression of reionization of the galaxies is seen in the form of growing bubble size over redshift.

    Using information about mean bubble size and luminosity from DRAGONS, a relationship between the two can be found. This helps us in sampling appropriate galaxies to survey from the future Wide-Field Infrared Survey Telescope High Latitude Survey (WFIRST-HLS).

    NASA/WFIRST

    Fig 2. shows that the mean bubble size \bar{R}, increases linearly with luminosity. (Another example of associating bubble size and luminosity can be seen in this astrobite.)

    3
    Fig. 2: The authors show through simulation of reionization bubbles around galaxies that they have a linear relationship between the mean bubble size \bar{R} and the UV magnitude M_{UV}

    1cm Bubble Observing with the SKA

    The Square Kilometer Array (SKA) is an upcoming radio interferometer array located in South Africa and Western Australia.

    SKA-Square Kilometer Array


    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)

    It will consist of 1 sq. km of collecting area, making it the most sensitive array to ever exist, and a perfect instrument for observing the 21cm signal. Observation of the 21cm signal is dependent on the differential brightness temperature, \delta T_b.

    \delta T_b \propto x_{HI}(1+\delta)(1 – \frac{T_{\gamma}}{T_{S}})

    The differential brightness temperature depends on the dark matter over-density \delta (small fluctuations in the density), the spin temperature T_S, the CMB temperature T_{\gamma}, and the fraction of neutral hydrogen x_{HI}. It’s important to note that \delta T_b is spatially dependent, as both \delta and x_{HI} depend on position.

    For simulating the observation of the 21cm differential brightness temperature from the cosmic dawn, they use the SKA1-Low specifications which determine the sensitivity (see here for some basic interferometry) and observational hours required . But the sensitivity of the SKA isn’t enough, so stacking spectra (averaging observations over frequency) must be used. By focusing on high redshift galaxies (z > 9) predicted from the WFIRST-HLS, and stacking future SKA1-Low observations centered on these galaxies, the bubbles from reionization should be observable. An example of how likely these bubbles can be measured is seen in Fig. 3, which shows that the signal to noise ratio (SNR) grows considerably for stacking 100+ galaxy observations in the case where T_{S} >> T_{\gamma} (right).

    4
    Fig. 3: The SNR for observing reionization bubbles increases if more spectra are stacked (100,200,300) and if \delta T_b is saturated (right), which means \delta T_b >> T_{\gamma}.

    It appears from the author’s results that imaging individual bubbles from reionization doesn’t seem too likely as there is too much uncertainty in redshift and a high sensitivity required from the radio interferometer. But the technique the authors of today’s astrobite describe of stacking spectra over many galaxies does appear to provide that extra sensitivity for a measurement. There is also the big caveat of this being an ideal case, because our observations of the early universe are troubled by bright galactic and extragalactic foregrounds. The work in this astrobite also demonstrates that making a measurement of reionization and its characteristic bubbles may rely on a synthesized approach e.g. using both 21cm and near infrared observations.

    See the full article here .

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    What do we do?

    Astrobites is a daily astrophysical literature journal written by graduate students in astronomy. Our goal is to present one interesting paper per day in a brief format that is accessible to undergraduate students in the physical sciences who are interested in active research.
    Why read Astrobites?

    Reading a technical paper from an unfamiliar subfield is intimidating. It may not be obvious how the techniques used by the researchers really work or what role the new research plays in answering the bigger questions motivating that field, not to mention the obscure jargon! For most people, it takes years for scientific papers to become meaningful.
    Our goal is to solve this problem, one paper at a time. In 5 minutes a day reading Astrobites, you should not only learn about one interesting piece of current work, but also get a peek at the broader picture of research in a new area of astronomy.

     
  • richardmitnick 1:20 pm on May 18, 2017 Permalink | Reply
    Tags: APEX Low-redshift Legacy Survey of MOlecular Gas, , , , , , SKA - Square Kilometre Array   

    From SKA: “International team completes large survey of gas in nearby galaxies” 

    SKA Square Kilometer Array

    SKA

    An international team of investigators led by Dr. Claudia Cicone (INAF – Astronomical Observatory of Brera), Dr. Matt Bothwell (University of Cambridge) and with the SKA Organisation Project Scientist Dr. Jeff Wagg as principal investigator have found the spectra of the carbon monoxide emission line in a sample of small but nearby galaxies and found that the most massive galaxies form stars and are rich in metals.

    1
    The 12m APEX ESO telescope, located on the plateau of Chajnantor in Chile, at 5000m altitude.

    The team, comprising investigators from Italy, the UK, Germany, Chile and China have completed a large survey of molecular gas in nearby galaxies using the 12m APEX telescope in Chile. The APEX Low-redshift Legacy Survey of MOlecular Gas (ALLSMOG, PI: Dr. Jeff Wagg) has observed the Carbon Monoxide (CO) molecule in a sample of 97 galaxies in the local Universe. The ALLSMOG data provide important information on the cold molecular gas content of these galaxies which have been well characterised in terms of their star-formation rates, gas-phase metallicities and atomic HI gas masses.

    ALLSMOG is an ESO observing program conceived by Dr. Jeff Wagg to study the molecular gas through the carbon monoxide emission line with the telescope Atacama Pathfinder Experiment (Apex), a collaboration between the Max Planck Institute for Radio Astronomy (MPIfR), the Onsala Space Observatory (Oso) and ESO, which is located on the plain of Chajnantor at 5000 meters above sea level, in the Chilean Andes.

    The article The final release date of ALLSMOG: a survey of CO in typical local low-M star-forming galaxies published today in the journal Astronomy & Astrophysics includes observations of 97 galaxies, 88 of whom studied with Apex (for more than 300 hours of observation from summer 2013 to winter 2015/2016) and 9 with the telescope of the Institute of millimetric radio astronomy (Iram) to Pico Veleta, Spain (between 2014 and 2015).

    IRAM 30m Radio telescope, on Pico Veleta in the Spanish Sierra Nevada

    The survey is the first major campaign ALLSMOG systematic observation of carbon monoxide extragalactic made with Apex telescope.

    “The ALLSMOG survey is the first large systematic extragalactic survey of CO ever conducted with the APEX telescope”, says Claudia Cicone, a Marie Skłodowska-Curie fellow at INAF- Osservatorio Astronomico di Brera. “Our research has an enormous legacy value because the entire scientific community can exploit our data. We really hope our efforts will stimulate new ideas and results.”

    “For all the galaxies in our sample we have additional information on their physical properties from optical observations and on their atomic gas content (HI) from radio observations of the HI21cm line published in previous studies and by other teams. We have created a real identikit of these galaxies which allows us to study the relations between the molecular gas and their other physical properties.”

    “In the near future, multi-wavelength galaxy studies like this will be greatly enhanced by data from the SKA telescope and its precursors such as ASKAP and MeerKAT”, says Dr. Jeff Wagg.

    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

    “While the SKA precursors are expected to detect more than half a million galaxies in HI line emission, these sample sizes have the potential to increase by nearly an order of magnitude when the SKA1-mid telescope comes online.”

    SKA1-mid is the dish array telescope to be built in South Africa that will be operating in the 350Mhz -14Ghz frequency range, complementary to the low-frequency telescope (so-called SKA1-low) to be built in Australia. Although SKA1-mid and the SKA precursors do not have the frequency coverage needed to measure the molecular gas in nearby galaxies, they will be able to detect the atomic gas through the 21cm atomic HI line transition.

    “Quantifying the total gas content (atomic and molecular) of significant samples of galaxies out to large distances remains one of the crucial elements needed for a full understanding of galaxy formation”, concludes Dr. Jeff Wagg.

    See the full article here .

    Please help promote STEM in your local schools.
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    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 2:11 pm on March 28, 2017 Permalink | Reply
    Tags: , , , , , , SKA - Square Kilometre Array   

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

    ICRAR Logo
    International Centre for Radio Astronomy Research

    March 28, 2017

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

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

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

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

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

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

    2
    Murchison Widefield Array (MWA) radio telescope

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

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

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

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

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

    PUBLICATION DETAILS

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

    See the full article here .

    Please help promote STEM in your local schools.
    STEM Icon

    Stem Education Coalition

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

    ICRAR is:

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

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

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

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

     
  • richardmitnick 10:25 am on March 10, 2017 Permalink | Reply
    Tags: , , , , , Mia Baquiran, , SKA - Square Kilometre Array   

    From CSIRO: Women in STEM – “One woman’s role in designing the world’s largest radio telescope” Mia Baquiran 

    CSIRO bloc

    Commonwealth Scientific and Industrial Research Organisation

    10th March 2017
    Helen Sim

    1
    Mia Baquiran. When they flick the switch on the world’s largest telescope, one woman’s work will come to life.

    If it takes a village to raise a child, it takes a planet – or at least ten countries – to build the the world’s largest radio telescope, the Square Kilometre Array.

    The Square Kilometre Array, or SKA, is a next-generation radio telescope that will be vastly more sensitive than the best present-day instruments. It will give astronomers remarkable insights into the formation of the early Universe, including the emergence of the first stars, galaxies and other structures.

    Consisting of thousands of antennas linked together by high bandwidth optical fibre, the SKA will require new technologies and progress in fundamental engineering. The telescope’s design and development is being led by the international SKA Organisation.

    Radio telescopes add to observations made by optical and other telescopes by revealing different information about stars, galaxies and gas clouds. Because radio waves can pass through clouds of dust and gas, radio telescopes are able to observe objects and processes not visible to other telescopes.

    2
    An artist’s impression of the Square Kilometre Array’s antennas in Australia. ©SKA Organisation

    Construction is due to start in 2018 and around the globe 11 groups, all with members from several countries, are working feverishly on different aspects of the project to make it come together.

    Australia has a presence in several of these groups, and indeed leads two of them. Our very own Mia Baquiran is one of the researchers working on this exciting project.

    She spends her days in a quiet, ground-floor office in a leafy suburb of Sydney, working on systems that will go into the international SKA radio telescope.

    Mia’s role in this ‘moon-shot’ project concerns a telescope called ‘SKA Low’, an assembly of more than a quarter of a hundred thousand low-frequency antennas that will be housed at CSIRO’s Murchison Radio-astronomy Observatory in Western Australia.

    3
    CSIRO’s ASKAP antennas under construction at the Murchison Radio-astronomy Observatory in Western Australia

    SKA Low has no moving parts but it is still a complex beast. The signals from the antennas have to be brought together and compared with each other (‘correlated’) to create a view of the sky.

    Mia is working on the system (the correlator and beamformer) that does this. She writes ‘permanent’ software (firmware) for controlling the subsystems of the correlator and beamformer.

    4
    Our research engineer Mia Baquiran is working on the software that will create a view of the sky using the SKA Low radio telescope.

    So how did she get into this space you might ask?

    “When I was thinking about what I wanted to do at university I didn’t have that much direction,” Mia said. “Really the only thing that got me excited was the concept of engineering, being able to develop things and understanding how things work.”

    She was always interested in physics and robotics appealed too, so she headed for a degree in mechatronics, a field that brings together mechanical engineering, electronics and software.

    After finishing her studies at UNSW in 2012 she worked at a small software company, then joined our astronomy and space science research area.

    Mia loves problem solving. “There’s always that wonderful moment when you finally find a solution,” she said.

    She’s also curiosity-driven. “I like the idea that I can learn something new every day,” she said. “Engineering is constantly changing, so you have to become a lifelong learner.”

    “I do enjoy the opportunity to learn from people who are more experienced than me, and that’s definitely well-facilitated in CSIRO.”

    Because the correlator and beamformer project is international Mia has had the opportunity to visit the Netherlands to work with colleagues there.

    The SKA will give radio astronomers a view of the past a million years after the Big Bang, when the universe first evolving to what is referred to as the “cosmic dawn”.

    But what’s in store for Mia in her future?

    “I’d like to continue in electronics and FPGA (field programmable gate array) design,” she said.

    “Ideally I’d like to continue in radio astronomy, because we’re in a special position being in Australia, where it’s one of the fields that we’re world leaders in.”

    Find out more about how CSIRO is helping to bring the Square Kilometre Array to life.

    See the full article here .

    Please help promote STEM in your local schools.

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    CSIRO campus

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

     
  • richardmitnick 11:49 am on January 18, 2017 Permalink | Reply
    Tags: , BAOs, SKA - Square Kilometre Array   

    From astrobites: “Detecting Cosmic Sound using the Square Kilometer Array” 

    Astrobites bloc

    Astrobites

    Jan 18, 2017
    Joshua Kerrigan

    Title: Baryonic acoustic oscillations from 21cm intensity mapping: the Square Kilometre Array case

    Authors: Francisco Villaescuse-Navarro, David Alonso, and Matteo Viel
    First Author’s Institution: Osservatorio Astronomico di Trieste, INAF
    1
    Status: Published in MNRAS, [open access]

    You may be familiar with the tagline from the movie Alien, “In space, no one can hear you scream”, but what if I told you on cosmological scales there is somewhat of an exception? During the earliest periods of the universe, cosmic forces led to a phenomenon that would be analogous to sound. In today’s bite, we will see how astronomers plan to detect these oscillations.

    Cosmological Sound or Baryon Acoustic Oscillations

    The competing forces of gravity and radiation pressure, caused fluctuations in the densities of galaxies and the Intergalactic Medium (IGM), resulting in periodic dense and under-dense regions of space. The oscillations in density are what we refer to as Baryon Acoustic Oscillations (BAOs). They provide a standard ruler for cosmological scales comparable to how supernovae are used as standard candles, and therefore can be very useful for constraining cosmological parameters.

    How to detect Ancient Sound

    The Square Kilometer Array (SKA) is one of the most ambitious, if not the most ambitious radio telescope arrays ever proposed.

    SKA Square Kilometer Array
    SKA CSIRO  Pathfinder Telescope
    SKA

    It will cover the radio bandwidth of 50 MHz to 14 GHz by utilizing several different antenna designs and have a square kilometer of collecting area. Today’s paper only concerns the Phase 1 mid to high frequency (350 MHz to 14 GHz) array of the SKA, known as SKA1-Mid.

    Detection of BAOs can be accomplished by a large scale mapping of unresolved emission from neutral hydrogen (HI), also known as the 21cm emission (for its wavelength). HI can give us this ability to map out huge swaths of space, as it is the most abundant element in the universe and exists everywhere. However it’s not as simple as using a radio telescope and pointing towards the sky. Galactic and extragalactic foregrounds that are extremely bright can overpower the BAO signal and there is also the issue of the instrument’s response (how the receiver sees a signal) and noise. To determine the feasibility of detecting BAOs using SKA1-Mid with this technique, the authors turn to simulation. They simulate a cosmological HI signal and galactic/extragalactic foregrounds, as if they were observed by the proposed SKA1-Mid in single dish mode for intensity mapping. There were then 3 versions of the final simulations to compare, one with just the cosmological HI signal, the HI signal + instrument noise, and the HI signal + foregrounds + instrument noise.

    Some wiggle room for BAOs

    2
    Figure 1: Measurements of a simulation (Red) with only the HI cosmological signal. It can be seen that the models with BAOs (Blue) closely follow the measurements of the HI signal, but the real test is whether the SKA1-Mid can detect the BAO signal through foregrounds and noise.

    The authors report a difficulty in accurately pinning down a BAO detection at low (z~0.6) and high (z~2.5) redshifts. At low redshifts a detection is limited by a weak BAO signal, while the high redshift region is limited by the telescope beam size smearing out the signal and reducing the signal to noise ratio. In Fig. 1 the cosmological HI signal (free of noise or foregrounds) was sampled and fit to 2 models, a BAO and non-BAO model. In that case, a very clear detection could be technically possible. They go on to show that when including foregrounds and instrument response, the number of simulations with clear detections over redshift begin to drop. The highest redshift bin closest to the end of reionization at z=2.5, shows a decline to 75% of simulations with a clear BAO detection.

    These results point out that a potential BAO detection for the SKA1 could be right around the corner, lending support to previous BAO measurements by the Sloan Digital Sky Survey and WiggleZ. We are certainly entering an exciting era of radio astronomy and cosmology. These new instruments have the ability to give us a wealth of new information on BAOs, fast radio bursts, the epoch of reionization and the cosmic dark ages.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    What do we do?

    Astrobites is a daily astrophysical literature journal written by graduate students in astronomy. Our goal is to present one interesting paper per day in a brief format that is accessible to undergraduate students in the physical sciences who are interested in active research.
    Why read Astrobites?

    Reading a technical paper from an unfamiliar subfield is intimidating. It may not be obvious how the techniques used by the researchers really work or what role the new research plays in answering the bigger questions motivating that field, not to mention the obscure jargon! For most people, it takes years for scientific papers to become meaningful.
    Our goal is to solve this problem, one paper at a time. In 5 minutes a day reading Astrobites, you should not only learn about one interesting piece of current work, but also get a peek at the broader picture of research in a new area of astronomy.

     
  • richardmitnick 4:08 pm on October 28, 2016 Permalink | Reply
    Tags: , , , , , SKA - Square Kilometre Array   

    From icrar: “Australian Desert Telescope Views Sky in Radio Technicolor” 

    ICRAR Logo
    International Centre for Radio Astronomy Research

    10.28.16

    Dr Natasha Hurley-Walker (Curtin University, ICRAR)
    E: nhw@icrar.org
    M: +61 426 192 677

    Associate Professor Randall Wayth (Curtin University, ICRAR, CAASTRO)
    E: randall.wayth@icrar.org
    M: +61 418 282 359

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

    Tamara Hunter, Media Contact, Curtin University
    E: tamara.hunter@curtin.edu.au
    M: +61 (08) 9266 3353

    1
    A ‘radio colour’ view of the sky above a ‘tile’ of the Murchison Widefield Array radio telescope, located in outback Western Australia. The Milky Way is visible as a band across the sky and the dots beyond are some of the 300,000 galaxies observed by the telescope for the GLEAM survey. Red indicates the lowest frequencies, green the middle frequencies and blue the highest frequencies. Credit: Radio image by Natasha Hurley-Walker (ICRAR/Curtin) and the GLEAM Team. MWA tile and landscape by Dr John Goldsmith / Celestial Visions.

    A telescope located deep in the West Australian outback has shown what the Universe would look like if human eyes could see radio waves.

    Published today in the Monthly Notices of the Royal Astronomical Society, the GaLactic and Extragalactic All-sky MWA, or ‘GLEAM’ survey, has produced a catalogue of 300,000 galaxies observed by the Murchison Widefield Array (MWA), a $50 million radio telescope located at a remote site northeast of Geraldton.

    Lead author Dr Natasha Hurley-Walker, from Curtin University and the International Centre for Radio Astronomy Research (ICRAR), said this is the first radio survey to image the sky in such amazing technicolour.

    “The human eye sees by comparing brightness in three different primary colours – red, green and blue,” Dr Hurley-Walker said.

    “GLEAM does rather better than that, viewing the sky in 20 primary colours.

    “That’s much better than we humans can manage, and it even beats the very best in the animal kingdom, the mantis shrimp, which can see 12 different primary colours,” she said.

    GLEAM is a large-scale, high-resolution survey of the radio sky observed at frequencies from 70 to 230 MHz, observing radio waves that have been travelling through space—some for billions of years.

    “Our team are using this survey to find out what happens when clusters of galaxies collide,” Dr Hurley-Walker said.

    “We’re also able to see the remnants of explosions from the most ancient stars in our galaxy, and find the first and last gasps of supermassive black holes.”

    MWA Director Associate Professor Randall Wayth, from Curtin University and ICRAR, said GLEAM is one of the biggest radio surveys of the sky ever assembled.

    “The area surveyed is enormous,” he said. “Large sky surveys like this are extremely valuable to scientists and they’re used across many areas of astrophysics, often in ways the original researchers could never have imagined,” Associate Professor Wayth said.

    Completing the GLEAM survey with the MWA is a big step on the path to SKA-low, the low frequency part of the international Square Kilometre Array (SKA) radio telescope to be built in Australia in the coming years.

    SKA Square Kilometer Array

    “It’s a significant achievement for the MWA telescope and the team of researchers that have worked on the GLEAM survey,” Associate Professor Wayth said.

    The MWA

    The Murchison Widefield Array (MWA) is a low frequency radio telescope located at the Murchison Radio-astronomy Observatory in Western Australia’s Mid West.

    SKA Murchison Widefield Array, in Western Australia

    The MWA observes radio waves with frequencies between 70 and 320 MHz and was the first of the three Square Kilometre Array (SKA) precursors to be completed.

    A consortium of 13 partner institutions from four countries (Australia, USA, India and New Zealand) has financed the development, construction, commissioning and operations of the facility. Since commencing operations in mid 2013 the consortium has grown to include new partners from Canada and Japan.

    Key science for the MWA ranges from the search for redshifted HI signals from the Epoch of Reionisation to wide-field searches for transient and variable objects (including pulsars and Fast Radio Bursts), wide-field Galactic and extra-galactic surveys, and solar and heliospheric science.

    The SKA

    The Square Kilometre Array (SKA) project is an international effort to build the world’s largest radio telescope, led by SKA Organisation based at the Jodrell Bank Observatory near Manchester, England. Co-located primarily in South Africa and Western Australia, the SKA will be a collection of hundreds of thousands of radio antennas with a combined collecting area equivalent to approximately one million square metres, or one square kilometre. 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.

    See the full article here .

    Please help promote STEM in your local schools.
    STEM Icon

    Stem Education Coalition

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

    ICRAR is:

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

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

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

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

     
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