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  • richardmitnick 3:06 pm on July 14, 2018 Permalink | Reply
    Tags: , , , , Meerkat, , ,   

    From University of Oxford: “MeerKAT telescope unveiled in South Africa” 

    U Oxford bloc

    From University of Oxford

    SKA Meerkat telescope, South African design

    13 Jul 2018

    MeerKAT consists of 64 interconnected dishes, each 13.5m in diameter, that together form a single radio telescope. MeerKAT is an impressive South African achievement, assisted by a cohort of international scientists, including researchers from Oxford University and the Africa Oxford Initiative.

    MeerKAT will detect radio waves from the far reaches of the cosmos, allowing scientists to address some of the most puzzling questions and processes of the Universe. The device is able to better detect neutral hydrogen gas – the fundamental building block of the Universe, which is the building block of all the things that we see in the night sky, such as galaxies and stars. Insights from the telescope will support astrophysicists to understand how this gas becomes a star over time. MeerKAT will also be used to conduct tests in fundamental physics, including General Relativity and high-energy astrophysics through observations of pulsars and transients.

    The telescope was officially launched at a ceremony in Carnarvon in the Northern Cape, attended by David Mabuza the Deputy President of South Africa, and other science and technology ministers from the SA government, as well as representatives from the teams involved in building the telescope and those planning to lead the science based on the data it will deliver.

    Researchers from Oxford’s Department of Physics play leading roles in four of the largest surveys to be carried out with MeerKAT. The deep radio continuum survey (MIGHTEE) will study how galaxies evolve over the history of the universe, and THUNDERKAT aims to detect phenomena which go bang, such as when stars collide together, bursts of radiation when a star dies and accretion events that trigger black holes. The TRAPUM and MeerTIME projects aim at finding new pulsars and fast radio transients, and using them to test our understanding of extreme physics, respectively.

    Professor Matt Jarvis, Principal Investigator of the MIGHTEE survey and a Professor of Astrophysics at Oxford, said: Initial data from MeerKAT has shown that it will be one of the premier facilities for radio astronomy until the SKA, I’m sure that we will see some fantastic results over the next few years that will greatly enhance our understanding of how galaxies form and evolve.

    The telescope will be the largest of its kind, until the Square Kilometre Array (SKA). When completed, the SKA, will be 50 to 100 times more sensitive than any other radio telescope on Earth, and insights from MeerKAT will be combined with this data to give a comprehensive overview of the history of the universe. Dr Ian Heywood, a Hintze Fellow at Oxford’s Department of Astrophysics, has a leading role in the team, producing MeerKAT images, including some of the most impressive shots of the centre of our Galaxy ever generated, unveiled at the inauguration ceremony.

    2
    First Array Release 1.5 images taken with MeerKAT 32
    SKA SA Chief Scientist Dr Fernando Camilo and SKA SA Head of Science Commissioning Dr Sharmila Goedhart, released to the Minister of Science and Technology, Naledi Pandor, the recent AR1.5 results, images achieved by using various configurations of the 32 antennas currently operational in the Karoo.

    3
    MeerKAT produces First Light image
    The MeerKAT First Light image of the sky shows unambiguously that MeerKAT is already the best radio telescope of its kind in the Southern Hemisphere. Array Release 1 (AR1) provides 16 of an eventual 64 dishes integrated into a working telescope array. It is the first significant scientific milestone achieved by MeerKAT.

    5
    This Is The Clearest View of The Centre of The Milky Way to Date, And It Is Breathtaking. (SARAO). Science Alert

    Dr Aris Karastergiou, a Physics lecturer at Oxford, who co-leads the Thousand Pulsar Array survey in the MeerTIME project, added: ‘MeerKAT is a fantastic instrument for pulsar science and a stepping stone to the SKA – our work on it will essentially set the stage for the SKA and move us forward to a whole different era of radio astronomy. The telescope has been a long time in the making and we are incredibly excited we can now commence our science projects. It is a remarkable achievement by our South African colleagues in collaboration with a large international scientific community.

    The lessons learned from constructing MeerkAT are already feeding into the design specification of the SKA, allowing us to test new algorithms that will allow us to turn the raw data into exceptionally detailed maps and time-domain data products that will be used throughout the scientific community.

    Dr. Anne Makena, Program Coordinator at the Africa Oxford Initiative (AfOx), said: ‘The Africa Oxford Initiative (AfOx) celebrates the official unveiling of the MeerKAT Telescope in South Africa. We are proud to be associated with the academics involved in this groundbreaking work both in Oxford and our partner institutions in Africa. This incredible achievement reflects the power of research collaborations, which AfOx will continue to facilitate.’

    MeerKAT has been in the making for the better part of the last decade. It is expected to lead to groundbreaking results within the next 5 years, leading to the era of SKA science.

    See the full article here.


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    U Oxford campus

    Oxford is a collegiate university, consisting of the central University and colleges. The central University is composed of academic departments and research centres, administrative departments, libraries and museums. The 38 colleges are self-governing and financially independent institutions, which are related to the central University in a federal system. There are also six permanent private halls, which were founded by different Christian denominations and which still retain their Christian character.

    The different roles of the colleges and the University have evolved over time.

     
  • richardmitnick 2:42 pm on June 19, 2018 Permalink | Reply
    Tags: ASKAP, , , , , Meerkat, , ,   

    From AAAS: “New radio telescope in South Africa will study galaxy formation” 

    AAAS

    From AAAS

    Jun. 19, 2018
    Daniel Clery

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

    Today, the Square Kilometre Array (SKA), a continent-spanning radio astronomy project, announced that Spain has come on board as the collaboration’s 11th member. That boost will help the sometimes-troubled project as, over the next year or so, it forms an international treaty organization and negotiates funding to start construction. Meanwhile, on the wide-open plains of the Karoo, a semiarid desert northeast of Cape Town, South Africa, part of the telescope is already in place in the shape of the newly completed MeerKAT, the largest and most powerful radio telescope in the Southern Hemisphere.

    The last of 64 13.5-meter dishes was installed late last year, and next month South African President Cyril Ramaphosa will officially open the facility. Spread across 8 kilometers, the dishes have a collecting area similar to that of the great workhorse of astrophysics, the Karl G. Jansky Very Large Array (VLA) near Socorro, New Mexico.

    NRAO/Karl V Jansky VLA, on the Plains of San Agustin fifty miles west of Socorro, NM, USA, at an elevation of 6970 ft (2124 m)

    But with new hardware designs and a powerful supercomputer to process data, the newcomer could have an edge on its 40-year-old northern cousin.

    “For certain studies, it will be the best” in the world, says Fernando Camilo, chief scientist of the South African Radio Astronomy Observatory in Cape Town, which operates MeerKAT. Sensitive across a wide swath of the radio spectrum, MeerKAT can study how hydrogen gas moves into galaxies to fuel star formation. With little experience, South Africa has “a major fantastic achievement,” says Heino Falcke of Radboud University in Nijmegen, the Netherlands.

    MeerKAT, which stands for Karoo Array Telescope along with the Afrikaans word for “more,” is one of several precursor instruments for the SKA. . The first phase of the SKA could begin in 2020 at a cost of €798 million. It would add another 133 dishes to MeerKAT, extending it across 150 kilometers, and place 130,000 smaller radio antennas across Australia—but only if member governments agree to fully fund the work. Months of delicate negotiations lie ahead. “In every country, people are having that discussion on what funding is available,” Falcke says.

    With MeerKAT’s 64 dishes now in place, engineers are learning how to process the data they gather. In a technique called interferometry, computers correlate the signals from pairs of dishes to build a much sharper image than a single dish could produce. For early science campaigns last year, 16 dishes were correlated. In March, the new supercomputer came online, and the team hopes to be fully operational by early next year. “It’s going to be a challenge,” Camilo says.

    MeerKAT’s dishes are smaller than the VLA’s, but having more of them puts it in “a sweet spot of sensitivity and resolution,” Camilo says. Its dishes are split into a densely packed core, which boosts sensitivity, and widely dispersed arms, which increase resolution. The VLA can opt for sensitivity or resolution, but not both at once—and only after the slow process of moving its 27 dishes into a different configuration.

    The combination makes MeerKAT ideal for mapping hydrogen, the fuel of star and galaxy formation. Because of a spontaneous transition in the atoms of neutral hydrogen, the gas constantly emits microwaves with a wavelength of 21 centimeters. Stretched to radio frequencies by the expansion of the universe, these photons land in the telescope’s main frequency band. It should have the sensitivity to map the faint signal to greater distances than before, and the resolution to see the gas moving in and around galaxies.

    MeerKAT will also watch for pulsars, dense and rapidly spinning stellar remnants. Their metronomic radio wave pulses serve as precise clocks that help astronomers study gravity in extreme conditions. “By finding new and exotic pulsars, MeerKAT can provide tests of physics,” says Philip Best of the University of Edinburgh. Falcke wants to get a better look at a highly magnetized pulsar discovered in 2013. He hopes it will shed light on the gravitational effects of the leviathan it orbits: the supermassive black hole at the center of the Milky Way.

    Other SKA precursors are taking shape. The Australian SKA Pathfinder (ASKAP) at the Murchison Radio-astronomy Observatory in Western Australia is testing a novel survey technology with its 36 12-meter dishes that could be used in a future phase of the SKA.

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

    Whereas a conventional radio dish has a single-element detector—the equivalent of a single pixel—the ASKAP’s detectors have 188 elements, which should help it quickly map galaxies across large areas of the sky.

    Nearby is the Murchison Widefield Array (MWA), an array of 2048 antennas, each about a meter across, that look like metallic spiders.

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

    Sensitive to lower frequencies than MeerKAT, the MWA can pick up the neutral hydrogen signal from as far back as 500 million years after the big bang, when the first stars and galaxies were lighting up the universe. Astronomers have been chasing the faint signal for years, and earlier this year, one group reported a tentative detection. “We’re really curious to see if it can be replicated,” says MWA Director Melanie Johnston-Hollitt of Curtin University in Perth, Australia.

    If the MWA doesn’t deliver a verdict, the SKA, with 130,000 similar antennas, almost certainly will. Although the MWA may detect the universe lighting up, the SKA intends to map out where it happened.

    The American Association for the Advancement of Science is an international non-profit organization dedicated to advancing science for the benefit of all people.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.


    Stem Education Coalition

     
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