From ALMA: “ALMA Discovers Hidden Spiral Arms Embracing a Young Star”

ALMA

29 September 2016
Valeria Foncea

Education and Public Outreach Officer

Joint ALMA Observatory

Santiago, Chile

Tel: +56 2 467 6258

Cell: +56 9 75871963
Email: valeria.foncea@alma.cl

Charles E. Blue
Public Information Officer
National Radio Astronomy Observatory
Charlottesville, Virginia, USA
Tel: +1 434 296 0314
Cell: +1 202 236 6324
E-mail: cblue@nrao.edu

Richard Hook
Public Information Officer, ESO

Garching bei München, Germany

Tel: +49 89 3200 6655

Cell: +49 151 1537 3591
Email: rhook@eso.org

Masaaki Hiramatsu

Education and Public Outreach Officer, NAOJ Chile
Observatory
Tokyo, Japan

Tel: +81 422 34 3630

E-mail: hiramatsu.masaaki@nao.ac.jp

ALMA peered into the Ophiuchus star-forming region to study the protoplanetary disk around the young star Elias 2-27. Astronomers discovered a striking spiral pattern in the disk. This feature is the product of density waves – gravitational perturbations in the disk. Credit: L. Pérez (MPIfR), B. Saxton (NRAO/AUI/NSF), ALMA (ESO/NAOJ/NRAO), NASA/JPL Caltech/WISE Team.

Swirling around the young star Elias 2-27, astronomers discovered a stunning spiral-shape pinwheel of dust. This striking feature, seen with the Atacama Large Millimeter/submillimeter Array (ALMA), is the product of density waves – gravitational perturbations in the disk that produce sweeping arms reminiscent of a spiral galaxy, but on a much smaller scale.

“These observations are the first direct evidence for density waves in a protoplanetary disk,” said Laura Perez, an astronomer with the Max Planck Institute for Radio Astronomy in Bonn, Germany, and lead author on a paper published in the journal Science.

Previously, astronomers noted compelling spiral features on the surfaces of protoplanetary disks, but it was unknown if these same spiral patterns also emerged deep within the disk where planet formation takes place. ALMA, for the first time, was able to peer deep into the mid-plane of a disk and discovered the clear signature of spiral density waves.

Nearest to the star, ALMA found a familiar flattened disk of dust, which extends past the orbit of Neptune in our own solar system. Beyond that point, ALMA detected a narrow band with significantly less dust, which may be indicative of a planet in formation. Springing from the outer edge of this gap are two sweeping spiral arms that extend more than 10 billion kilometers away from their host star.

ALMA discovered sweeping spiral arms in the protoplanetary disk surrounding the young star Elias 2-27. This spiral feature was produced by density waves – gravitational perturbations in the disk. Credit: B. Saxton (NRAO/AUI/NSF); ALMA (ESO/NAOJ/NRAO)

Finding density waves at these extreme distances may have implications for planet-formation theory, Perez notes. The standard picture of planet formation begins with small planetesimals coming together under gravity. In the outer reaches of a disk, where there is a dearth of planetesimals, gravitational instabilities may also lead directly to the formation of a planet. ALMA’s detection of spiral density waves may be evidence that such a process is taking place.

Elias 2-27 is located approximately 450 light-years from Earth in the Ophiuchus star-forming complex. Even though it contains only about half the mass of our Sun, this star has an unusually massive protoplanetary disk. The star is estimated to be at least one million years old and still encased in its parent molecular cloud, obscuring it from optical telescopes.

“There are still questions of how these features form. Perhaps they are the result of a newly forged planet interacting with the protoplanetary disk or simply gravitational instabilities driven by the shear mass of the disk,” said Perez. “ALMA will further dissect this and other similar disks in an upcoming large program, helping astronomers understand the seemingly chaotic forces that eventually give rise to stable planetary systems like our own.”

The team is composed of L. Perez (Max Planck Institute for Radio Astronomy, Bonn, Germany), J. Carpenter (Joint ALMA Observatory, Santiago, Chile), S. Andrews (Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass.), L. Ricci (Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass.), A. Isella (Rice University, Houston, Texas), H. Linz (Max Planck Institute for Astronomy, Heidelberg, Germany), A. Sargent (Caltech, Pasadena, Calif.), D. Wilner (Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass.), T. Henning (Max Planck Institute for Astronomy, Heidelberg, Germany), A. Deller (The Netherlands Institute for Radio Astronomy, Dwingeloo), C. Chandler (National Radio Astronomy Observatory, Socorro, N.M.), C. Dullemond (Heidelberg University, Germany), J. Lazio (Caltech, Pasadena, Calif.), K. Menten (Max Planck Institute for Radio Astronomy, Bonn, Germany), S. Corder (Joint ALMA Observatory, Santiago, Chile), S. Storm (Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass.), L. Testi (European Southern Observatory, Garching, Germany), M. Tazzari (European Southern Observatory, Garching, Germany), W. Kwon (Korean Astronomy and Space Science Institute, Daejeon), N. Calvert (University of Michigan, Ann Arbor), J. Greaves (Cardiff University, U.K.), R. Harris (University of Illinois, Urbana), L. Mundy (University of Maryland, College Park).

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The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

From ALMA: “ALMA Catches Stellar Cocoon with Curious Chemistry”

ALMA

29 September 2016
Contacts

Takashi Shimonishi
Frontier Research Institute for Interdisciplinary Sciences
Tohoku University, Sendai, Miyagi, Japan
Email: shimonishi@astr.tohoku.ac.jp

Masaaki Hiramatsu
NAOJ Chile Observatory EPO officer
Tel: +81 422 34 3630
Email: hiramatsu.masaaki@nao.ac.jp

Nicolás Lira T.
Education and Public Outreach Coordinator
Joint ALMA Observatory
Santiago, Chile
Tel: +56 2 24 67 65 19
Cell: +56 9 94 45 77 26
Email: nicolas.lira@alma.cl

Richard Hook
Public Information Officer, ESO

Garching bei München, Germany

Tel: +49 89 3200 6655

Cell: +49 151 1537 3591
Email: rhook@eso.org

Charles E. Blue
Public Information Officer
National Radio Astronomy Observatory
Charlottesville, Virginia, USA
Tel: +1 434 296 0314
Cell: +1 202 236 6324
E-mail: cblue@nrao.edu

A hot and dense mass of complex molecules, cocooning a newborn star, has been discovered by a Japanese team of astronomers using ALMA. This unique hot molecular core is the first of its kind to have been detected outside the Milky Way galaxy. It has a very different molecular composition from similar objects in our own galaxy — a tantalising hint that the chemistry taking place across the Universe could be much more diverse than expected.

A team of Japanese researchers have used the power of the Atacama Large Millimeter/submillimeter Array (ALMA) to observe a massive star known as ST11 [1] in our neighbouring dwarf galaxy, the Large Magellanic Cloud (LMC). Emission from a number of molecular gases was detected. These indicated that the team had discovered a concentrated region of comparatively hot and dense molecular gas around the newly ignited star ST11. This was evidence that they had found something never before seen outside of the Milky Way — a hot molecular core [2].

Takashi Shimonishi, an astronomer at Tohoku University, Japan, and the paper’s lead author enthused: “This is the first detection of an extragalactic hot molecular core, and it demonstrates the great capability of new generation telescopes to study astrochemical phenomena beyond the Milky Way.”

The ALMA observations revealed that this newly discovered core in the LMC has a very different composition to similar objects found in the Milky Way. The most prominent chemical signatures in the LMC core include familiar molecules such as sulfur dioxide, nitric oxide, and formaldehyde — alongside the ubiquitous dust. But several organic compounds, including methanol (the simplest alcohol molecule), had remarkably low abundance in the newly detected hot molecular core. In contrast, cores in the Milky Way have been observed to contain a wide assortment of complex organic molecules, including methanol and ethanol.

Takashi Shimonishi explains: “The observations suggest that the molecular compositions of materials that form stars and planets are much more diverse than we expected.”

Fig.2 Left: Distributions of molecular line emission from a hot molecular core in the Large Magellanic Cloud observed with ALMA. Emissions from dust, sulfur dioxide (SO2), nitric oxide (NO), and formaldehyde (H2CO) are shown as examples. Right: An infrared image of the surrounding star-forming region (based on the 8 micron data provided by the NASA/Spitzer Space Telescope). Credit: T. Shimonishi/Tohoku University, ALMA (ESO/NAOJ/NRAO)

The LMC has a low abundance of elements other than hydrogen or helium [3]. The research team suggests that this very different galactic environment has affected the molecule-forming processes taking place surrounding the newborn star ST11. This could account for the observed differences in chemical compositions.

It is not yet clear if the large, complex molecules detected in the Milky Way exist in hot molecular cores in other galaxies. Complex organic molecules are of very special interest because some are connected to prebiotic molecules formed in space. This newly discovered object in one of our nearest galactic neighbours is an excellent target to help astronomers address this issue. It also raises another question: how could the chemical diversity of galaxies affect the development of extragalactic life?

Notes

[1] ST11’s full name is 2MASS J05264658-6848469. This catchily-named young massive star is defined as a Young Stellar Object. Although it currently appears to be a single star, it is possible that it will prove to be a tight cluster of stars, or possibly a multiple star system. It was the target of the science team’s observations and their results led them to realise that ST11 is enveloped by a hot molecular core.

[2] Hot molecular cores must be: (relatively) small, with a diameter of less than 0.3 light-years; have a density over a thousand billion (1012) molecules per cubic metre (far lower than the Earth’s atmosphere, but high for an interstellar environment); warm in temperature, at over –173 degrees Celsius. This makes them at least 80 degrees Celsius warmer than a standard molecular cloud, despite being of similar density. These hot cores form early on in the evolution of massive stars and they play a key role in the formation of complex chemicals in space.

[3] The nuclear fusion reactions that take place when a star has stopped fusing hydrogen to helium generate heavier elements. These heavier elements get blasted into space when massive dying stars explode as supernovae. Therefore, as our Universe has aged, the abundance of heavier elements has increased. Thanks to its low abundance of heavier elements, the LMC provides insight into the chemical processes that were taking place in the earlier Universe.

More information

This research was presented in a paper published in the Astrophysical Journal on August 9, 2016, entitled The Detection of a Hot Molecular Core in the Large Magellanic Cloud with ALMA.

The team is composed of Takashi Shimonishi (Frontier Research Institute for Interdisciplinary Sciences & Astronomical Institute, Tohoku University, Japan), Takashi Onaka (Department of Astronomy, The University of Tokyo, Japan), Akiko Kawamura (National Astronomical Observatory of Japan, Japan) and Yuri Aikawa (Center for Computational Sciences, The University of Tsukuba, Japan).

See the full article here .

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The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

From SKA via Science Business: “Square Kilometre Array prepares for the ultimate big data challenge”

SKA

Science | Business

22 September 2016
Éanna Kelly

The world’s most powerful radio telescope will collect more information each day than the entire internet. Major advances in computing are required to handle this data, but it can be done, says Bernie Fanaroff, strategic advisor for the SKA

The Square Kilometre Array (SKA), the world’s most powerful telescope, will be ready from day one to gather an unprecedented volume of data from the sky, even if the supporting technical infrastructure is yet to be built.

“We’ll be ready – the technology is getting there,” Bernie Fanaroff, strategic advisor for the most expensive and sensitive radio astronomy project in the world, told Science|Business.

Construction of the SKA is due to begin in 2018 and finish sometime in the middle of the next decade. Data acquisition will begin in 2020, requiring a level of processing power and data management know-how that outstretches current capabilities.

Astronomers estimate that the project will generate 35,000-DVDs-worth of data every second. This is equivalent to “the whole world wide web every day,” said Fanaroff.

The project is investing in machine learning and artificial intelligence software tools to enable the data analysis. In advance of construction of the vast telescope – which will consist of some 250,000 radio antennas split between sites in Australia and South Africa – SKA already employs more than 400 engineers and technicians in infrastructure, fibre optics and data collection.

The project is also working with IBM, which recently opened a new R&D centre in Johannesburg, on a new supercomputer. SKA will have two supercomputers to process its data, one based in Cape Town and one in Perth, Australia.

Recently, elements of the software under development were tested on the world’s second fastest supercomputer, the Tianhe-2, located in the National Supercomputer Centre in Guangzhou, China. It is estimated a supercomputer with three times the power of Tianhe-2 will need to be built in the next decade to cope with all the SKA data.

In addition to the analysis, the project requires large off-site data warehouses. These will house storage devices custom-built in South Africa. “There were too many bells and whistles with the stuff commercial providers were offering us. It was far too expensive, so we’ve designed our own servers which are cheaper,” said Fanaroff.

Fanaroff was formerly director of SKA, retiring at the end of 2015, but remaining as a strategic advisor to the project. He was in Brussels this week to explore how African institutions could gain access to the European Commission’s new Europe-wide science cloud, tentatively scheduled to go live in 2020.

Ten countries are members of the SKA, which has its headquarters at Manchester University’s Jodrell Bank Observatory, home of the world’s third largest fully-steerable radio telescope. The bulk of SKA’s funding has come from South Africa, Australia and the UK.

Currently its legal status is as a British registered company, but Fanaroff says the plan is to create an intergovernmental arrangement similar to CERN. “The project needs a treaty to lock in funding,” he said.

Early success

On SKA’s website is a list of five untold secrets of the cosmos, which the telescope will explore. These include how the very first stars and galaxies formed just after the Big Bang.

However, Fanaroff, believes the Eureka moment will be something nobody could have imagined. “It’ll make its name, like every telescope does, by discovering an unknown, unknown,” he said.

A first taste of the SKA’s potential arrived in July through the MeerKAT telescope, which will form part of the SKA. MeerKAT will eventually consist of 64 dishes, but the power of the 16 already installed has surpassed Fanaroff’s expectations.

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

The telescope revealed over a thousand previously unknown galaxies. “Two things were remarkable: when we switched it on, people told us it was going to take a long time to work. But it collected very good images from day one. Also, our radio receivers worked four times better than specified,” he said. Some 500 scientists have already booked time on the array.

Researchers with the Breakthrough Listen project, a search for intelligent life funded by Russian billionaire Yuri Milner, would also like a slot, Fanaroff said. Their hunt is exciting and a good example of the sort of bold mission for which SKA will be built. “It’s high-risk, high-reward territory. If you search for aliens and you find nothing, you end your career with no publications. But on the other hand you could be involved in one of the biggest discoveries ever,” said Fanaroff.

Golden age

SKA has helped put South Africa’s scientific establishment in the shop window says Fanaroff, referring to the recent Nature Index, which indicates the country’s scientists are publishing record levels of high-quality research, mostly in astronomy. “It’s the start of a golden age,” Fanaroff predicted.

Not that the SKA does not have its critics. With so much public funding going to the telescope, “Some scientists were a little bit bitter at the beginning,” Fanaroff said. “But that has faded with the global interest from science and industry we’re attracting. The SKA can go on to be a platform for all science in Africa, not just astronomy.”

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SKA ASKAP Pathefinder Telescope

SKA Meerkat Telescope

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.

From AARNet: “Building the Square Kilometre Array”

AARNet

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No writer credit found

AARNet is among the Australian participants in the global Square Kilometre Array project

The Square Kilometre Array (SKA) project is an ambitious global scientific and engineering project to build the world’s largest most sensitive telescope co-located in remote desert regions of southern Africa and Western Australia. The project is currently in the design and pre-construction phase. Australia and New Zealand collaborated to establish the SKA candidate site in Western Australia and also to build the Australian SKA Pathfinder (ASKAP) telescope now located there.

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

When the SKA is operational, hundreds of thousands of antennas will hugely increase the ability of astronomers to explore the far reaches of the universe and address mysteries around dark energy, gravity and life elsewhere.

Watch this video produced by the Australian Government Department of Industry for an explanation about the project and the role Australia plays:

You can also learn all about the SKA project at the SKA Organisation website.

More than 250 scientists and engineers from 18 countries and nearly 100 institutions, universities and industry will be involved in ‘work packages’ for different elements of the design. Australian industry and research institutes will participate in seven of the eleven work packages, with AARNet working with CSIRO in Signal and Data Transport (including synchronisation) (SaDT).

Expanding the network to meet the needs of the SKA

To enable Australia’s participation in the SKA project, AARNet expanded its network across the Nullabor, from Adelaide to Perth and on to the Murchison Radio Observatory (MRO), the future home of the SKA in remote outback Western Australia.

The newly deployed terrestrial network is capable of transmission speeds of up to 8 Terabits per second (Tbps). The network expansion is a component of the National Research Network (NRN) Project, an initiative of the Department of Innovation, Industry, Science and Research, funded from the Education Investment Fund under the Super Science (Future Industries)

Connecting the SKA precursor telescopes at the MRO

To develop technologies for the SKA, two precursor telescopes, the Australian SKA Pathfinder (ASKAP) and the Murchison Widefield Array (MWA), have been built and are now operating at the MRO. AARNet Interconnects the telescopes at the MRO with the computer processing required for extracting useful information from the signals. Fast reliable research network connectivity is critical for processing data generated from the new radio telescopes.

The Australian SKA Pathfinder (ASKAP) is an innovative new radio telescope consisting of 36 identical 12-metre wide dish antennas. Plans are in place to add 60 more dishes to the telescope in the SKA’s first phase. The ASKAP uses revolutionary Phased Array Feed (PAF) technology, developed in Australia by CSIRO and others, which enables each dish to survey the sky with a much wider field of view. The volume of data generated by the PAFs and low frequency receivers will be substantial.

CSIRO and AARNet worked together to connect the ASKAP antennas to the AARNet network. New optical fibres were laid between Geraldton and ASKAP, connecting to the new Geraldton-Perth link constructed by Nextgen Networks for the federal government-funded Regional Backbone Blackspots Program. This enables ASKAP to connect directly via a high-capacity link to the Pawsey supercomputing facilities in Perth.

The Murchison Widefield Array (MWA) is a revolutionary static low-frequency telescope that can be shared by observers studying different parts of the sky at the same time.

SKA Murchison Widefield Array, in Western Australia

Knowledge gained from the MWA will contribute to the development of the low-frequency component of the SKA to be built in Phase two.

AARNet and CSIRO collaborated to deliver a transmission network for the MWA. The network is installed on fibre optic infrastructure constructed by AARNet for the CSIRO and by Nextgen Networks for the federal government-funded Regional Backbone Blackspots Program.

AARNet is providing the network services for the transmission of the data between the MWA sensors and the Pawsey High Performance Computing Centre for SKA Science, located 800kms away in Perth.

The network is scalable to support the needs of the MWA now and into future early phases of the SKA.

See the full article here .

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AARNet provides critical infrastructure for driving innovation in today’s knowledge-based economy

Australia’s Academic and Research Network (AARNet) is a national resource – a National Research and Education Network (NREN). AARNet provides unique information communications technology capabilities to enable Australian education and research institutions to collaborate with each other and their international peer communities.

From Many Worlds: “Out Of The Darkness”

NASA NExSS

Many Worlds

2016-09-21
Marc Kaufman

http://www.cafescipa.org

Simulation of the “Dark Ages” of the universe, a period predicted by theorists to have lasted as long as several hundred million years after the Big Bang. The first hydrogen atoms in the universe had not yet coalesced into stars and galaxies. (NASA/WMAP)

Before there were galaxies with stars and exoplanets, there were galaxies with stars and no planets. Before there were galaxies without planets, there were massive singular stars.

And before that, there was darkness for more than 100 million years after the Big Bang — a cosmos without much, or at times any, light.

So how did the lights get turned on, setting the stage for all that followed? Scientists have many theories but so far only limited data.

In the coming years, that is likely to change substantially.

First, the James Webb Space Telescope, scheduled to launch in 2018, will be able to look back at distant galaxies and stars that existed in small or limited numbers during the so called Dark Ages.

NASA/ESA/CSA Webb Telescope annotated

They gradually became more prevalent and then suddenly (in astronomical terms) became common. Called the epoch of cosmic “reionization,” this period is an essential turning point in the evolution of the cosmos.

Less well known but also about to begin pioneering work into how and when the lights came on will be an international consortium led by a team at the University of California, Berkeley. Unlike the space-based JWST, this effort will use an array of radio telescopes under construction in the South African desert. The currently small array will expand quickly now thanks in large part to a $9.6 million grant recently announced from the National Science Foundation.

Named the Hydrogen Epoch of Reionization Array (HERA), the project will focus especially on the billion-year process that changed the fundamental particle physics of the universe to allow stars, galaxies and their light burst out like spring flowers after a long winter.

Ultimate 350 dishes, UC Berkeley Hydrogen Epoch of Reionization Array (HERA), at the Karoo desert site, South Africa

But unlike the JWST, which will be able to observe faint and very early individual galaxies and stars, HERA will be exploring the early universe as a near whole.

Before stars and galaxies became common, the universe went through a long period of darkness and semi-darkness, but ended with the “Epoch of Reionization.” (S.G. Djorgovski & Digital Media Center, Caltech)

Aaron Parsons, an associate professor at Berkeley and principal investigator of the HERA project, said his team is now ready to grow their proof-of-concept array to a full-fledged observatory with 270 radio telescopes, with science that just might give some solid answers about how the lights came on.

Parsons said they see their effort as a continuation of the earlier pioneering work that identified and mapped the cosmic microwave background radiation that was produced by another cosmos-changing event some 380,000 years after the Big Bang.

“We have learned 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,” Parsons said.

“We know from these experiments that the universe started out neutral {at that point}, and we know that it ended ionized, and we are trying to map out how it transitioned between those two.”

More specifically, here is what cosmologists and astrophysicists theorize or know happened:

The Big Bang produced a scorching cauldron of particles that had electrical charge. That condition ended with the ‘recombination” event that joined protons and neutrons together to form atomic hydrogen, and as a result produced the cosmic microwave background radiation.

What followed was 100 million or more years of abject darkness because the atomic hydrogen was neutral and unable to do much of anything. Some relatively few stars appeared in those Dark Ages, when enough gas clumped together and set off a star-forming gravitational collapse.

Those stars, and later dwarf galaxies, emitted photons which had the effect of splitting (or ionizing) the hydrogen that surrounded them — creating bubbles of charged hydrogen (and some helium) in a vast ocean of neutral hydrogen.

Much remains unknown about how and when the population of stars and galaxies grew over the ensuing hundreds of millions of years during this epoch of reionization. But a time came, an estimated one billion years after the Big Bang, when the islands of split hydrogen turned into a universe of split hydrogen. That made widescale star and galaxy formation possible.

Many astronomers study primordial stars and galaxies to learn about this still mysterious process, but the HERA project will analyze instead how those earliest celestial objects changed the nature of intergalactic space. And that essentially means capturing tiny changes in the vast universe of uncharged hydrogen during and after the Dark Ages, since hydrogen was most of what was present.

As Parsons explained it, the changes within hydrogen atoms they are looking for were weak and occurred only infrequently — perhaps once in 10 million years for a single atom of hydrogen. “But there’s an awful lot of hydrogen out there, and that allows the weakness to be an advantage. That means we can see through clouds, can see deep into the hydrogen clouds,” and that allows for observing on a much longer time scale.

The goal of the HERA project is, most broadly, to trace those minute changes in hydrogen from about 100 million years after the Big Bang to one billion years after, when the epoch of reionization culminated with a conclusive turning on of the universe.

An artist rendering of the “bubbles” of ionized atoms theorized to have surrounded the earliest stars. As Parsons explained: “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. Eventually, they all intersected and you got this über bubble, leaving the universe as we observe it today.” (Illustration from Scientific American)

The HERA array currently has 19 radio telescopes, will grow to 37 soon, and to 270 in 2018.

19 dishes, UC Berkeley Hydrogen Epoch of Reionization Array (HERA), at the Karoo desert site, South Africa

The team hopes to some day expand to 350 telescopes. Each is a of radio dish looking fixedly upwards and measuring primordial radiation. It was originally emitted at a wavelength of 21 centimeters, a key spectral tracer for the neutral hydrogen atom. The photons have been been stretched by a factor of 10 or more since it was emitted some 13 billion years ago, making the detections more easily measured.

The signal is nonetheless weak and has been difficult to measure. 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 sufficiently powerful and sensitive. But HERA is much more powerful and hopes are high.

UC Berkeley led Precision Array Probing The Epoch Of Reionization (PAPER)

SKA Murchison Widefield Array, in Western Australia

The researchers will be looking for the boundaries between those bubbles of ionized hydrogen around early stars — which are invisible to HERA — and the surrounding neutral or atomic hydrogen being measured. By tuning the receiver to different wavelengths, they can map the bubble boundaries at different distances to follow the the evolution of the bubbles over time.

HERA is being constructed at the Karoo desert site where PAPER was deployed. Joining the Berkeley team will be scientists from England, South Africa, Italy, MIT, the National Radio Astronomical Observatory, the University of Washington, Arizona State University and others.

HERA was recently granted the status of a precursor telescope for the Square Kilometer Array (SKA), an ambitious project to build a vast collection of radio dishes around Africa and Australia — thereby creating the largest astronomical observatory of all time. HERA is located close by one of the South African SKA sites.

See the full article here .

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About Many Worlds

There are many worlds out there waiting to fire your imagination.

Marc Kaufman is an experienced journalist, having spent three decades at The Washington Post and The Philadelphia Inquirer, and is the author of two books on searching for life and planetary habitability. While the “Many Worlds” column is supported by the Lunar Planetary Institute/USRA and informed by NASA’s NExSS initiative, any opinions expressed are the author’s alone.

This site is for everyone interested in the burgeoning field of exoplanet detection and research, from the general public to scientists in the field. It will present columns, news stories and in-depth features, as well as the work of guest writers.

About NExSS

The Nexus for Exoplanet System Science (NExSS) is a NASA research coordination network dedicated to the study of planetary habitability. The goals of NExSS are to investigate the diversity of exoplanets and to learn how their history, geology, and climate interact to create the conditions for life. NExSS investigators also strive to put planets into an architectural context — as solar systems built over the eons through dynamical processes and sculpted by stars. Based on our understanding of our own solar system and habitable planet Earth, researchers in the network aim to identify where habitable niches are most likely to occur, which planets are most likely to be habitable. Leveraging current NASA investments in research and missions, NExSS will accelerate the discovery and characterization of other potentially life-bearing worlds in the galaxy, using a systems science approach.
The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs. NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.

From ALMA: “ALMA Uncovers Secrets of Giant Space Blob”

ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres
ALMA

21 September 2016
Jim Geach
Centre for Astrophysics Research, University of Hertfordshire
Hatfield, UK
Email: j.geach@herts.ac.uk

Matthew Hayes
Stockholm University
Stockholm, Sweden
Tel: +46 (0)8 5537 8521
Email: matthew@astro.su.se

Richard Hook
ESO Public Information Officer
Garching bei München, Germany
Tel: +49 89 3200 6655
Cell: +49 151 1537 3591
Email: rhook@eso.org

Nicolás Lira T.
Education and Public Outreach Coordinator
Joint ALMA Observatory
Santiago, Chile
Tel: +56 2 24 67 65 19
Cell: +56 9 94 45 77 26
Email: nicolas.lira@alma.cl

Charles E. Blue
Public Information Officer
National Radio Astronomy Observatory
Charlottesville, Virginia, USA
Tel: +1 434 296 0314
Cell: +1 202 236 6324
E-mail: cblue@nrao.edu

An international team using ALMA, along with ESO’s Very Large Telescope and other telescopes, has discovered the true nature of a rare object in the distant Universe called a Lyman-alpha Blob. Up to now astronomers did not understand what made these huge clouds of gas shine so brightly, but ALMA has now seen two galaxies at the heart of one of these objects and they are undergoing a frenzy of star formation that is lighting up their surroundings. These large galaxies are in turn at the centre of a swarm of smaller ones in what appears to be an early phase in the formation of a massive cluster of galaxies. The two ALMA sources are expected to evolve into a single giant elliptical galaxy.

This diagram explains how a Lyman-alpha Blob, one of the largest and brightest objects in the Universe, shines. Credit: ESO/J. Geach

Lyman-alpha Blobs (LABs) are gigantic clouds of hydrogen gas that can span hundreds of thousands of light-years and are found at very large cosmic distances. The name reflects the characteristic wavelength of ultraviolet light that they emit, known as Lyman-alpha radiation [1]. Since their discovery, the processes that give rise to LABs have been an astronomical puzzle. But new observations with ALMA may now have now cleared up the mystery.

One of the largest Lyman-alpha Blobs known, and the most thoroughly studied, is SSA22-Lyman-alpha blob 1, or LAB-1. Embedded in the core of a huge cluster of galaxies in the early stages of formation, it was the very first such object to be discovered — in 2000 — and is located so far away that its light has taken about 11.5 billion years to reach us.

A team of astronomers, led by Jim Geach, from the Centre for Astrophysics Research of the University of Hertfordshire, UK, has now used the Atacama Large Millimeter/Submillimeter Array’s (ALMA) unparallelled ability to observe light from cool dust clouds in distant galaxies to peer deeply into LAB-1. This allowed them to pinpoint and resolve several sources of submillimetre emission [2].

They then combined the ALMA images with observations from the Multi Unit Spectroscopic Explorer (MUSE) instrument mounted on ESO’s Very Large Telescope (VLT), which map the Lyman-alpha light. This showed that the ALMA sources are located in the very heart of the Lyman-alpha Blob, where they are forming stars at a rate over 100 times that of the Milky Way.

ESO/VLT at Cerro Paranal, Chile

ESO MUSE

Deep imaging with the NASA/ESA Hubble Space Telescope and spectroscopy at the W. M. Keck Observatory [3] showed in addition that the ALMA sources are surrounded by numerous faint companion galaxies that could be bombarding the central ALMA sources with material, helping to drive their high star formation rates.

NASA/ESA Hubble Telescope

NASA/ESA Hubble STIS

Keck Observatory, Mauna Kea, Hawaii, USA

Keck/MOSFIRE on Keck 1, Mauna Kea, Hawaii, USA

The team then turned to a sophisticated simulation of galaxy formation to demonstrate that the giant glowing cloud of Lyman-alpha emission can be explained if ultraviolet light produced by star formation in the ALMA sources scatters off the surrounding hydrogen gas. This would give rise to the Lyman-alpha Blob we see.

Jim Geach, lead author of the new study, explains: “Think of a streetlight on a foggy night — you see the diffuse glow because light is scattering off the tiny water droplets. A similar thing is happening here, except the streetlight is an intensely star-forming galaxy and the fog is a huge cloud of intergalactic gas. The galaxies are illuminating their surroundings.”

Understanding how galaxies form and evolve is a massive challenge. Astronomers think Lyman-alpha Blobs are important because they seem to be the places where the most massive galaxies in the Universe form. In particular, the extended Lyman-alpha glow provides information on what is happening in the primordial gas clouds surrounding young galaxies, a region that is very difficult to study, but critical to understand.

Jim Geach concludes, “What’s exciting about these blobs is that we are getting a rare glimpse of what’s happening around these young, growing galaxies. For a long time the origin of the extended Lyman-alpha light has been controversial. But with the combination of new observations and cutting-edge simulations, we think we have solved a 15-year-old mystery: Lyman-alpha Blob-1 is the site of formation of a massive elliptical galaxy that will one day be the heart of a giant cluster. We are seeing a snapshot of the assembly of that galaxy 11.5 billion years ago.”

Additional images:

Giant space blob glows from within

This image shows one of the largest known single objects in the Universe, the Lyman-alpha blob LAB-1. This picture is a composite of two different images taken with the FORS instrument on the Very Large Telescope (VLT) — a wider image showing the surrounding galaxies and a much deeper observation of the blob itself at the centre made to detect its polarisation. The intense Lyman-alpha ultraviolet radiation from the blob appears green after it has been stretched by the expansion of the Universe during its long journey to Earth. These new observations show for the first time that the light from this object is polarised. This means that the giant “blob” must be powered by galaxies embedded within the cloud. Credit: ESO/M. Hayes

ESO/FORS1

Closing in on a giant space blob

This sequence of images closes in on one of the largest known single objects in the Universe, the Lyman-alpha blob LAB-1. Observations with the ESO VLT show for the first time that this giant “blob” must be powered by galaxies embedded within the cloud. The image on the left shows a wide view of the constellation of Aquarius. The two images at the upper right were created from photographs taken through blue and red filters and forming part of the Digitized Sky Survey 2. The two images at the lower right were taken using the FORS camera on the VLT.
Credit: ESO/A. Fujii/M. Hayes and Digitized Sky Survey 2

Wide-field view of the sky around a giant space blob

This visible-light wide-field image of the region around the giant Lyman-alpha blob LAB1 was created from photographs taken through blue and red filters and forming part of the Digitized Sky Survey 2. The blob itself lies at the centre of the image but, despite being huge and very luminous, it is so distant that it is too faint to be seen clearly on this picture. The field of view is approximately 2.9 degrees across. Credit: ESO and Digitized Sky Survey 2

Notes

[1] The negatively charged electrons that orbit the positively charged nucleus in an atom have quantised energy levels. That is, they can only exist in specific energy states, and they can only transition between them by gaining or losing precise amounts of energy. Lyman-alpha radiation is produced when electrons in hydrogen atoms drop from the second-lowest to the lowest energy level. The precise amount of energy lost is released as light with a particular wavelength, in the ultraviolet part of the spectrum, which astronomers can detect with space telescopes or on Earth in the case of redshifted objects. For LAB-1, at redshift of z~3, the Lyman-alpha light is seen as visible light.

[2] Resolution is the ability to see that objects are separated. At low resolution, several bright sources at a distance would seem like a single glowing spot, and only at closer quarters would each source be distinguishable. ALMA’s high resolution has resolved what previously appeared to be a single blob into two separate sources.

[3] The instruments used were the Space Telescope Imaging Spectograph (STIS) on the NASA/ESA Hubble Space Telescope and the Multi-Object Spectrometer For Infra-Red Exploration (MOSFIRE) mounted on the Keck 1 telescope on Hawaii.
More information

This research was presented in a paper entitled ALMA observations of Lyman-α Blob 1: Halo sub-structure illuminated from within by J. Geach et al., to appear in the Astrophysical Journal.

The team is composed of J. E. Geach (Centre for Astrophysics Research, University of Hertfordshire, Hatfield, UK), D. Narayanan (Department of Physics and Astronomy, Haverford College, Haverford PA, USA; Department of Astronomy, University of Florida, Gainesville FL, USA), Y. Matsuda (National Astronomical Observatory of Japan, Mitaka, Tokyo, Japan; The Graduate University for Advanced Studies, Mitaka, Tokyo, Japan), M. Hayes (Stockholm University, Department of Astronomy and Oskar Klein Centre for Cosmoparticle Physics, Stockholm, Sweden), Ll. Mas-Ribas (Institute of Theoretical Astrophysics, University of Oslo, Oslo, Norway), M. Dijkstra (Institute of Theoretical Astrophysics, University of Oslo, Oslo, Norway), C. C. Steidel (California Institute of Technology, Pasadena CA, USA ), S. C. Chapman (Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Canada ), R. Feldmann (Department of Astronomy, University of California, Berkeley CA, USA ), A. Avison (UK ALMA Regional Centre Node; Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, The University of Manchester, Manchester, UK), O. Agertz (Department of Physics, University of Surrey, Guildford, UK), Y. Ao (National Astronomical Observatory of Japan, Mitaka, Tokyo, Japan), M. Birkinshaw (H.H. Wills Physics Laboratory, University of Bristol, Bristol, UK), M. N. Bremer (H.H. Wills Physics Laboratory, University of Bristol, Bristol, UK), D. L. Clements (Astrophysics Group, Imperial College London, Blackett Laboratory, London, UK), H. Dannerbauer (Instituto de Astrofísica de Canarias, La Laguna, Tenerife, Spain; Universidad de La Laguna, Astrofísica, La Laguna, Tenerife, Spain), D. Farrah (Department of Physics, Virginia Tech, Blacksburg VA, USA), C. M. Harrison (Centre for Extragalactic Astronomy, Department of Physics, Durham University, Durham, UK), M. Kubo (National Astronomical Observatory of Japan, Mitaka, Tokyo, Japan), M. J. Michałowski (Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh, UK), D. Scott (Department of Physics & Astronomy, University of British Columbia, Vancouver, Canada), M. Spaans (Kapteyn Astronomical Institute, University of Groningen, Groningen, Netherlands) , J. Simpson (Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh, UK), A. M. Swinbank (Centre for Extragalactic Astronomy, Department of Physics, Durham University, Durham, UK ), Y. Taniguchi (The Open University of Japan, Chiba, Japan), E. van Kampen (ESO, Garching, Germany), P. Van Der Werf (Leiden Observatory, Leiden University, Leiden, The Netherlands), A. Verma (Oxford Astrophysics, Department of Physics, University of Oxford, Oxford, UK) and T. Yamada (Astronomical Institute, Tohoku University, Miyagi, Japan).

[This is the ESO release on this work. At this time, ALMA has not released their article. When ALMA releases their article, I may substitute it for this article. But this article makes very clear that this is an ALMA project.]
[I have added from the ALMA release Nicolás Lira T and Charles E. Blue to the contact list above]
[There is no material difference between the ESO and ALMA releases.]

See the full article here .

See the full ALMA release here .

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The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

From phys.org: “Twin jets pinpoint the heart of an active galaxy”

phys.org

September 19, 2016
No writer credit

3-mm GMVA image of the galaxy NGC 1052 showing a compact region at the centre and two jets (bottom), and sketch of the system with an accretion disk and two regions of entangled magnetic fields forming two powerful jets (top). The compact region in the image pinpoints the location of the supermassive black hole at the heart of NGC 1052, and the enormous magnetic fields surrounding the event horizon trigger the two powerful jets observed with our radio telescopes. Credit: Anne-Kathrin Baczko et al., Astronomy & Astrophysics

An international team of astronomers has measured the magnetic field in the vicinity of a supermassive black hole. A bright and compact feature of only 2 light days in size was directly observed by a world-wide ensemble of millimeter-wave radio telescopes in the heart of the active galaxy NGC 1052. The observations yield a magnetic field value at the event horizon of the central black hole between 0.02 and 8.3 Tesla. The team, led by the PhD student Anne-Kathrin Baczko, believes that such a large magnetic field provides enough magnetic energy to power the strong relativistic jets in active galaxies. The results are published in the present issue of Astronomy & Astrophysics.

The technique used to investigate the inner details of NGC 1052 is known as very-long-baseline interferometry, and has the potential to locate compact jet cores at sizes close to the event horizon of the powering black hole. The black hole itself remains invisible. Usually, the black hole position can only be inferred indirectly by tracking the wavelength-dependent jet-core position, which converges to the jet base at zero wavelength. The unknown offset from the jet base and the black hole makes it difficult to measure fundamental physical properties in most galaxies. The striking symmetry observed in the reported observations between both jets in NGC1052 allows the astronomers to locate the true center of activitiy inside the central feature, which makes, with the exception of our Galactic Centre, the most precisely known location of a super massive black hole in the universe. Anne-Kathrin Baczko, who performed this work at the Universities of Erlangen-Nürnberg and Würzburg and at the Max-Planck-Institut für Radioastronomie, says: “NGC 1052 is a true key source, since it pinpoints directly and unambiguously the position of a supermassive black hole in the nearby universe.”

NGC 1052 is an elliptical galaxy in a distance of approximately 60 million light years in the direction of the constellation Cetus (the Whale).

Three telescopes participating in the Global Millimetre VLBI Array (GMVA): MPIfR’s Effelsberg 100m (above), IRAM’s Pico Veleta 30m (lower left) and Plateau de Bure 15m telescopes (lower right). Credit: IRAM (Pico Veleta & Plateau de Bure); Norbert Junkes (Effelsberg & compilation)

The magnetic field by the supermassive black hole was determined measuring the compactness and the brightness of the central region of the elliptical galaxy NGC 1052. This feature is as compact as 57 microarcseconds in diameter, equivalent to the size of a DVD on the surface of the moon. This amazing resolution was obtained by the Global mm-VLBI Array, a network of radio telescopes in Europe, the USA, and East Asia, that is managed by the Max-Planck-Institut für Radioastronomie. “It yields unprecedented image sharpness, and is soon to be applied to get event-horizon scales in nearby objects”, says Eduardo Ros from the MPI für Radioastronomie and collaborator in the project.

The unique powerful twin jets at a close distance, similar to the well-known active galaxy M 87, puts NGC 1052 in the pole position for future observations of nearby powerful galaxies in the oncoming era opened by the addition of ALMA, the Atacama Large Millimetre array, to the world-wide networks in radio interferometry.

The observation may help solving the long-standing mystery of how the powerful relativistic jets are formed, that can be seen in many active galaxies. The result has important astrophysical implications, since we see that jets can be driven by the extraction of magnetic energy from a rapidly rotating supermassive black hole.

More information: A.-K. Baczko et al. A highly magnetized twin-jet base pinpoints a supermassive black hole, Astronomy & Astrophysics (2016). DOI: 10.1051/0004-6361/201527951

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About Phys.org in 100 Words

Phys.org™ (formerly Physorg.com) is a leading web-based science, research and technology news service which covers a full range of topics. These include physics, earth science, medicine, nanotechnology, electronics, space, biology, chemistry, computer sciences, engineering, mathematics and other sciences and technologies. Launched in 2004, Phys.org’s readership has grown steadily to include 1.75 million scientists, researchers, and engineers every month. Phys.org publishes approximately 100 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Quancast 2009 includes Phys.org in its list of the Global Top 2,000 Websites. Phys.org community members enjoy access to many personalized features such as social networking, a personal home page set-up, RSS/XML feeds, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.

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

UC Berkeley

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.

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.

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.“

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 .
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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.

From SETI: “OSIRIS-REx says hello to the ATA!”

SETI Institute

Undated
No writer credit found

SETI/Allen Telescope Array situated at the Hat Creek Radio Observatory, 290 miles (470 km) northeast of San Francisco, California, USA

The ATA uses 42 radio dishes to search for radio transmissions from ET. How do we know the system is working? To answer that we point the dishes in the direction of a spacecraft we know is transmitting radio signals back to Earth. If our software detects a radio transmission at the exact frequency as the spacecraft’s transmission we know things are working as they should. On September 11, 2016 we tested the ATA by pointing at the newly launched NASA Osiris-REx spacecraft.

The detection of the radio transmission can be visualized as in the image below. The top graph is frequency on the horizontal axis, time on the vertical axis. The signal strength is represented by the brightness. You can clearly see the carrier signal as the solid line in the middle, and the data sidebands at the sides.

The bottom graph is the same data represented a bit differently. Frequency on the horizontal graph, signal strength on the vertical axis.

The frequency and strength of the signal detected, as shown in the image below, was exactly as we predicted for this spacecraft. This was indeed the Osiris-REx radio transmission to Earth. Our radio transmission system passed the test.

The ATA’s unique wide field of view was designed to be the best instrument to search for SETI signals, but is therefore also well suited to search for spacecraft, which the SETI Institute has done successfully for NASA and others on previous occasions.

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From CSIRO via The Sidney Morning Herald: Women in STEM – “Eureka prizes: Lisa Harvey-Smith’s vision for astronomy lands her award for promoting Australian research”

Commonwealth Scientific and Industrial Research Organisation

The Sidney Morning Herald

August 31 2016
Marcus Strom

Black hole hunter Dr Lisa Harvey-Smith has won the Eureka Prize for Promoting Understanding of Australian Science Research. Photo: Ian Warden

Dr Harvey-Smith, a CSIRO radio astronomer, is project scientist for the Australian Square Kilometre Array Pathfinder (ASKAP), a radio telescope in Western Australia that is allowing scientists to ask fundamental questions about the nature of our universe, including how galaxies are formed.

SKA ASKAP radio telescope

But as a child in Britain in the 1980s and ’90s there were other influences that brought Dr Harvey-Smith to think about the final frontier.

“As a kid, it was BBC TV shows like Tomorrow’s World and watching Helen Sharman​ become the first British woman in space that made me wonder what the future would be like,” she said.

And she said even “a weird, old man” like Patrick Moore presenting The Sky At Night, was a “great role model, even for a girl”.

“His passion shone through. People who are clearly knowledgeable about their area are great role models,” she said

And few show such passion for astronomy in Australia today than Dr Harvey-Smith. Her Eureka award “recognises her enthusiasm for the project and her capacity to articulate complex science to the general public with an insatiable appetite for all things astronomy”.

But what brought her from England to Australia?

“Australia is extremely good at astronomy – radio astronomy in particular,” she said. “It’s great to be in a country where astronomy is a priority.”

Her work on ASKAP is helping to lay the ground for the Square Kilometre Array to come in five years or so. It will be the largest radio telescope in history, spanning two continents [Australia and Africa].

“We will see further, deeper and fainter than we ever have before,” Dr Harvey-Smith said. “We will be able to better understand black holes and witness gravitational wave events, not just from those waves but from the light they emit, as well.”

The Australian Museum Eureka Prizes were celebrated on Wednesday night at Sydney’s Town Hall.

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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.