From The Chinese Academy of Sciences [中国科学院](CN): “Exploring Dark Matter and the First Bright Galaxies Simultaneously – 21-cm Forest Probe May Unlock Secrets of Early Universe”

From The Chinese Academy of Sciences [中国科学院](CN)

7.11.23
XU Ang
National Astronomical Observatories
E-mail: annxu@nao.cas.cn

The mystery of the first galaxies of the universe is an indomitable urge of human beings. The formation of them is mastered by the nature of dark matter which is also one of the most important problems faced by fundamental physics. However, understanding the nature of dark matter—for example, whether it is cold or warm—and its subsequent effect on the first galaxy formation is a huge challenge.

Now, a joint research team from Northeastern University (China) and the National Astronomical Observatories of the Chinese Academy of Sciences (NAOC) has proposed using a novel probe to try to shed light on the nature of dark matter and the early formation of galaxies simultaneously.

The team’s study was published in Nature Astronomy [below] on July 6.

Abstract
The absorption features in spectra of high-redshift background radio sources, caused by hyperfine structure lines of hydrogen atoms in the intervening structures, are known collectively as the 21-cm forest. They provide a unique probe of small-scale structures during the epoch of reionization, and can be used to constrain the properties of the dark matter (DM) thought to govern small-scale structure formation. However, the signals are easily suppressed by heating processes that are degenerate with a warm DM model. Here we propose a probe of both the DM particle mass and the heating history of the Universe, using the one-dimensional power spectrum of the 21-cm forest. The one-dimensional power spectrum measurement not only breaks the DM model degeneracy but also increases the sensitivity, making the probe actually feasible. Making 21-cm forest observations with the upcoming Square Kilometre Array has the potential to simultaneously determine both the DM particle mass and the heating level in the early Universe, shedding light on the nature of DM and the first galaxies.

Fig 1.

Fig. 2 The simulated 1-D power spectra of the 21-cm forest. (Image by Shao et al.)

SKA-Square Kilometer Array

SKA ASKAP Pathfinder Radio Telescope at the Inyarrimanha Ilgari Bundara Murchison Radio-astronomy Observatory (MRO), on the traditional lands of the Wajarri peoples.

SKA Murchison Widefield Array (AU), Boolardy station in outback Western Australia, at the Inyarrimanha Ilgari Bundara Murchison Radio-astronomy Observatory (MRO), on the traditional lands of the Wajarri peoples.

SKA Square Kilometre Array low frequency at the Inyarrimanha Ilgari Bundara Murchison Radio-astronomy Observatory (MRO), on the traditional lands of the Wajarri peoples.

The Massachusetts Institute of Technology Haystack Observatory EDGES telescope in a radio quiet zone the Inyarrimanha Ilgari Bundara Murchison Radio-astronomy Observatory (MRO), on the traditional lands of the Wajarri peoples.

SKA SARAO Meerkat [SKA-Mid] Telescope (SA), 90 km outside the small Northern Cape town of Carnarvon, SA.

The University of California-Berkeley Hydrogen Epoch of Reionization Array (HERA) SARAO SKA in the South African Karoo desert South Africa.

One way of understanding dark matter is to try to measure the mass of dark matter particles through cosmological observations of small-scale structures. But detecting small-scale structures in which no star formation has ever occurred is difficult, especially during the cosmic dawn. Fortunately, atomic hydrogen gas in and around these dark, small structures from cosmic dawn creates 21-cm absorption lines along the lines of sight between Earth and high-redshift radio point sources. These absorption lines are known collectively as the 21-cm forest.

The 21-cm forest probe is a theoretical concept proposed more than 20 years to probe for gas temperatures and potentially for dark matter properties during the cosmic dawn. So far, scientists have not attempted to actually use the probe due to numerous challenges, including extremely weak signals, the difficulty in identifying high-redshift background sources, and the degeneracy between the mass of dark matter particles and the heating effect, which would prevent the probe from constraining either the particle mass or the heating effect from the first galaxies.

Recently, though, a number of high-redshift radio-loud quasars have been discovered. In addition, construction on the Square Kilometre Array (SKA)—an international initiative to build the world’s largest radio telescope—began last December. Both these developments suggest that using the 21-cm forest probe will soon be feasible.

Inspired by power spectrum analyses widely used in cosmological probes, the NAOC researchers realized that the distinctive scale-dependences of the signals caused by the warm dark matter effect and the heating effect, respectively, could be used to statistically extract key features to distinguish the two effects.

In this study, the researchers proposed a novel statistical solution to simultaneously solve the weak signal problem and the degeneracy problem, by measuring the one-dimensional (1-D) power spectrum of the 21-cm forest. The signal scale-dependence revealed by the amplitude and shape of the 1-D power spectrum makes the 21-cm forest probe a viable and effective means of simultaneously measuring dark matter properties and the thermal history of the Universe.

“By measuring the one-dimensional power spectrum of the 21-cm forest, we can not only make the probe actually feasible by increasing the sensitivity, but also provide a way to distinguish the effects of warm dark matter models and early heating process,” said XU Yidong, corresponding author of the study. “We will be able to kill two birds with one stone!”

In scenarios where cosmic heating is not too severe, SKA Phase 1’s low-frequency array [above] will be capable of effectively constraining both dark matter particle mass and gas temperature. In cases where cosmic heating is more significant, utilizing multiple background radio sources during SKA Phase 2 will enable robust detection capabilities.

The 21-cm forest offers a viable means for constraining dark matter at redshift ranges beyond the reach of other observations. By measuring the heating level, the 21-cm forest provides a way to constrain the spectral properties of the first galaxies and the first black holes, so as to shed light on the nature of the first bright objects in the Universe. Using the 21-cm forest probe will serve as an indispensable avenue for advancing our understanding of the early Universe and peering into the mysteries of both dark matter and the first galaxies.

Since application of the 21-cm forest probe is closely tied to observations of high-redshift background radio sources, the next step will also involve identifying more radio-bright sources at the cosmic dawn (such as radio-loud quasars and gamma-ray burst afterglows) that can be followed up in the SKA era.

MOSEL Survey Dark Energy Camera Enables Astronomers a Glimpse at the Cosmic Dawn. Credit: The National Astronomical Observatory of Japan (国立天文台](JP).

Nature Astronomy

See the full article here .

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The Chinese Academy of Sciences[中国科学院](CN) is the national academy for the natural sciences of the People’s Republic of China. It has historical origins in the Academia Sinica during the Republican era and was formerly also known by that name. Collectively known as the “Two Academies (两院)” along with the Chinese Academy of Engineering, it functions as the national scientific think tank and academic governing body, providing advisory and appraisal services on issues stemming from the national economy, social development, and science and technology progress. It is headquartered in Xicheng District, Beijing, with branch institutes all over mainland China. It has also created hundreds of commercial enterprises, Lenovo being one of the most famous.

It is the world’s largest research organization, comprising around 60,000 researchers working in 114 institutes, and has been consistently ranked among the top research organizations around the world. It also holds the University of Science and Technology of China and the University of Chinese Academy of Sciences.

The Chinese Academy of Sciences has been ranked the No. 1 research institute in the world by Nature Index since the list’s inception in 2016 by Nature Portfolio. It is the most productive institution publishing articles of sustainable development indexed in Web of Science from 1981 to 2018 among all universities and research institutions in the world.

The Chinese Academy originated in the Academia Sinica founded, in 1928, by the Republic of China. After the Communist Party took control of mainland China in 1949, the residual of Academia Sinica was renamed Chinese Academy of Sciences (CAS), while others relocated to Taiwan.

The Chinese Academy of Sciences has six academic divisions:

Chemistry (化学部)
Information Technological Sciences (信息技术科学部)
Earth Sciences (地学部)
Life Sciences and Medical Sciences (生命科学和医学学部)
Mathematics and Physics (数学物理学部)
Technological Sciences (技术科学部)

The CAS has thirteen regional branches, in Beijing, Shenyang, Changchun, Shanghai, Nanjing, Wuhan, Guangzhou, Chengdu, Kunming, Xi’an, Lanzhou, Hefei and Xinjiang. It has over one hundred institutes and four universities (the University of Science and Technology of China at Hefei, Anhui, the University of the Chinese Academy of Sciences in Beijing, ShanghaiTech University, and Shenzhen Institute of Adavanced Technology). Backed by the institutes of CAS, UCAS is headquartered in Beijing, with graduate education bases in Shanghai, Chengdu, Wuhan, Guangzhou and Lanzhou, four Science Libraries of Chinese Academy of Sciences, three technology support centers and two news and publishing units. These CAS branches and offices are located in 20 provinces and municipalities throughout China. CAS has invested in or created over 430 science- and technology-based enterprises in eleven industries, including eight companies listed on stock exchanges.

Being granted a Fellowship of the Academy represents the highest level of national honor for Chinese scientists. The CAS membership system includes Academicians (院士), Emeritus Academicians (荣誉院士) and Foreign Academicians (外籍院士).

The Chinese Academy of Sciences was ranked #1 in the 2016, 2017, 2018, 2019, and 2020 Nature Index Annual Tables, which measure the largest contributors to papers published in 82 leading journals.

Research institutes

Beijing Branch
University of the Chinese Academy of Sciences (UCAS)
Academy of Mathematics and Systems Science
Institute of Acoustics (IOA)
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Institute of Botany, Chinese Academy of Sciences
Institute of Physics (IOPCAS)
Institute of Semiconductors
Institute of Electrical Engineering (IEE)
Institute of Information Engineering (IIE)
Institute of Theoretical Physics
Institute of High Energy Physics
Institute of Biophysics
Institute of Genetics and Developmental Biology
Institute of Electronics
National Astronomical Observatories
Institute of Computing Technology
Institute of Software
Institute of Automation
Beijing Institute of Genomics
Institute of Geographic Sciences and Natural Resources
Institute of Geology and Geophysics (IGG)
Institute of Remote Sensing and Digital Earth
Institute of Tibetan Plateau Research
Institute of Vertebrate Paleontology and Paleoanthropology
National Center for Nanoscience and Technology
Institute of Policy and Management
Institute of Psychology
Institute of Zoology
Changchun Branch
Changchun Institute of Optics, Fine Mechanics and Physics
Changchun Institute of Applied Chemistry
Northeast Institute of Geography and Agroecology
Changchun Observatory
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Chengdu Institute of Biology
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Chengdu Institute of Organic Chemistry
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Chongqing Institute of Green and Intelligent Technology
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South China Botanical Garden
Shenzhen Institutes of Advanced Technology
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Guangzhou Institute of Energy Conversion
Guangzhou Institute of Geochemistry
Guangzhou Institute of Biomedicine and Health
Guiyang Branch
Institute of Geochemistry
Hefei Branch
Hefei Institutes of Physical Science
University of Science and Technology of China
Kunming Branch
Kunming Institute of Botany
Kunming Institute of Zoology
Xishuangbanna Tropical Botanical Garden
Institute of Geochemistry
Yunnan Astronomical Observatory
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Lanzhou Institute of Chemical Physics
Lanzhou Institute of Geology
Northwest Institute of Plateau Biology
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Nanjing Botanical Garden, Memorial Sun Yat-Sen (Institute of Botany, Jiangsu Province and Chinese Academy of Science)
University of Chinese Academy of Sciences, Nanjing College
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Shanghai Astronomical Observatory
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Dalian Institute of Chemical Physics
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Xinjiang Technical Institute of Physics and Chemistry
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From ARC Centres of Excellence for All Sky Astrophysics in 3D (AU) : “Closing in on the first light in the Universe”

From ARC Centres of Excellence for All Sky Astrophysics in 3D (AU)

15 December, 2021

Tamzin Byrne
tamzin@scienceinpublic.com.au
+61 432 47 42 48

Niall Byrne
niall@scienceinpublic.com.au
+61 417 131 977

Dr Christene Lynch at MWA.

Research using new antennas in the Australian hinterland has reduced background noise and brought us closer to finding a 13-billion-year-old signal.

The early Universe was dark, filled with a hot soup of opaque particles. These condensed to form neutral hydrogen which coalesced to form the first stars in what astronomers call the Epoch of Reionisation (EoR).

“Finding the weak signal of this first light will help us understand how the early stars and galaxies formed,” says Dr Christene Lynch from ASTRO 3D, the ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions.

Dr Lynch is first author on a paper published in Publications of the Astronomical Society of Australia. She and her colleagues from Curtin University (AU) and the International Centre for Radio Astronomy Research (AU) have reduced the background noise in their observations allowing them to home in on the elusive signal.

The team worked with new equipment installed on the Murchison Widefield Array (MWA)[below], a radio telescope situated inland and some 800 kilometres north of Perth.

The MWA started operation a decade ago. One of its aims is to find the radio wave signature of that first light, known as the Epoch of Reionisation, or “EoR.”

Universe Atacama Large Millimiter/submillimeter Array (CL) [ALMA] Years After the Big Bang Credit: National Astronomical Observatory of Japan[国立天文台] (JP).

It comprises multiple low-frequency “antenna tiles” which work together to search the sky for the faint remnant of the out-pouring of ionised hydrogen atoms that accompanied first light, which began around 500 million to one billion years after the Big Bang.

Recently the number of antenna tiles was doubled from 128 to 256, significantly extending the land area occupied by the facility – and greatly upping its power.

By combining some of the existing tiles with 56 of the new ones, ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions scientist Dr Christene Lynch and her team were able to run a new sky experiment, called the Long Baseline Epoch of Reionisation Survey (LoBES), to refine the hunt for the long-sought signal.

“Our challenge is that the Universe is very, very crowded,” Dr Lynch explained.

“There are too many other radio sources that are much brighter than the EoR signal lying between it and us. It is like trying to hear someone whispering from across the room, when between you and that person there are thousands of other people shouting as loudly as possible.

“By using the new tiles and thus expanding the physical area over which the antenna work we were able to reduce a lot of that interference. As more and more of the tiles are added in, we’ll have a much better chance of finding the echo of that first light.”

Dr Lynch worked with colleagues from ASTRO 3D and the Curtin University (AU) node of the International Centre for Radio Astronomy Research [ICRAR].

They surveyed more than 80,000 radio signal sources, taking 16 spectral measurements for each. Running the results, they produced real and simulated models in which the noisiest foreground radio signals were reduced by a factor of three.

“The Epoch of Reionisation signal started life as a hydrogen atom radio wavelength of 21 centimetres,” explained Dr Lynch.

“Over the intervening billions of years it has been stretched and grown very, very faint. It’s clear that our new LoBES sky model will significantly improve efforts to properly locate it.”

Co-author Professor Cathryn Trott, an ASTRO 3D Chief Investigator with ICRAR and Curtin, added: “This is our deepest and most detailed view to-date of the radio sky in these EoR fields, and this new catalogue provides us with a cleaner path to locating the EoR signal – a detection that will be a very major achievement for astronomy.”

See the full article here .

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The ARC Centre of Excellence in All Sky Astrophysics in 3 Dimensions (AU)

Unifies over 200 world-leading astronomers to understand the evolution of the matter, light, and elements from the Big Bang to the present day.

We are combining Australian innovative 3D optical and radio technology with new theoretical supercomputer simulations on a massive scale, requiring new big data techniques.

Through our nationwide training and education programs, we are training young scientific leaders and inspiring high-school students into STEM sciences to prepare Australia for the next generation of telescopes: the Square Kilometre Array and the Extremely Large Optical telescopes.

The objectives for the ARC Centres of Excellence (AU) are to to:

Undertake highly innovative and potentially transformational research that aims to achieve international standing in the fields of research envisaged and leads to a significant advancement of capabilities and knowledge.

Link existing Australian research strengths and build critical mass with new capacity for interdisciplinary, collaborative approaches to address the most challenging and significant research problems.

Develop relationships and build new networks with major national and international centres and research programs to help strengthen research, achieve global competitiveness and gain recognition for Australian research

Build Australia’s human capacity in a range of research areas by attracting and retaining, from within Australia and abroad, researchers of high international standing as well as the most promising research students.

Provide high-quality postgraduate and postdoctoral training environments for the next generation of researchers.

Offer Australian researchers opportunities to work on large-scale problems over long periods of time.

Establish Centres that have an impact on the wider community through interaction with higher education institutes, governments, industry and the private and non-profit sector.

SKA Murchison Widefield Array (AU), Boolardy station in outback Western Australia, at the Murchison Radio-astronomy Observatory (MRO), on the traditional lands of the Wajarri peoples.

The Murchison Radio-astronomy Observatory,on the traditional lands of the Wajarri peoples, in outback Western Australia will house up to 130,000 antennas like these and the associated advanced technologies.

EDGES telescope in a radio quiet zone at the Murchison Radio-astronomy Observatory in Western Australia, on the traditional lands of the Wajarri peoples.

SKA ASKAP Pathfinder Radio Telescope.

From SKA South Africa (SA): “Large MeerKAT data release reveals beautiful new cosmic puzzles”

SKA South Africa

From SKA South Africa (SA)

11 November 2021

An international team led by a young South African researcher has just announced a comprehensive overview paper for the MeerKAT Galaxy Cluster Legacy Survey (MGCLS). The paper to be published in the Astronomy & Astrophysics journal presents some exciting, novel results, and is accompanied by the public release of a huge trove of curated data now available for astronomers worldwide to address a variety of challenging questions, such as those relating to the formation and evolution of galaxies throughout the universe.

Using The South African Radio Astronomy Observatory’s MeerKAT telescope [below], located in the Karoo region of the Northern Cape province, this first observatory-led survey demonstrates MeerKAT’s exceptional strengths by producing highly detailed and sensitive images of the radio emission from 115 clusters of galaxies. The observations, amounting to approximately 1000 hours of telescope time, were done in the year following the inauguration of MeerKAT in 2018.

“In those days we were still characterizing our new telescope, while developing further capabilities required by numerous scientists,” said Dr. Sharmila Goedhart, SARAO head of commissioning and science operations. “But we knew that MeerKAT was already very capable for studies of this sort, and we observed galaxy clusters as needed to fill gaps in the observing schedule.”

This was only the start. More than two years of work followed to convert the raw data into radio images, using powerful computers, and to perform scientific analysis addressing a variety of topics. This was done by a large team of South African and international experts led by Dr. Kenda Knowles of Rhodes University (SA) and SARAO.

MeerKAT view of a complex network of radio filaments and diffuse structure, spanning more than half a million light-years, related to a galaxy affected by dynamical activity in the nearby galaxy cluster Abell 85. Adapted from K. Knowles et al., The MeerKAT Galaxy Cluster Legacy Survey. I. Survey Overview and Highlights (Astronomy & Astrophysics, in press). Image credit: SARAO.

The force of gravity has filled the expanding universe with objects extending over an astounding range of sizes, from comets that are 10 km (one thirty-thousandth of a light-second) across, to clusters of galaxies that can span 10 million light-years. These galaxy clusters are complex environments, host to thousands of galaxies, magnetic fields, and large regions – millions of light-years across – of extremely hot (millions of degrees) gas, electrons and protons moving close to the speed of light, and dark matter. Those ‘relativistic’ electrons, spiraling around the magnetic fields, produce the radio emission that MeerKAT can ‘see’ with unprecedented sensitivity, opening new horizons for the deeper understanding of these structures. Thus MeerKAT, particularly when adding information from optical and infrared and X-ray telescopes, is exceptionally well-suited to studying the interplay between the components that determine the evolution of galaxy clusters, the largest structures in the universe held together by gravity.

We live in an ocean of air, but we can’t see it directly. However, if it’s filled with smoke or dust or water droplets, then suddenly we can see the gusts and swirls, whether they’re a gentle breeze or an approaching tornado. Similarly, the motions of the X-ray-glowing plasma in galaxy clusters are usually hidden from us. Radio emission from the sprinkling of relativistic electrons in this plasma can uncover the dramatic storms in clusters, stirred up when clusters collide with each other, or when jets of material spew out of supermassive black holes in the centers of galaxies.

The MGCLS paper just accepted for publication presents more than 50 newly discovered such patches of emission. Some of them we can understand and others remain a mystery, awaiting advances in our understanding of the physical behavior of cluster plasmas. A few examples are shown here, some associated with the bright emission from so-called ‘radio galaxies,’ powered by the jets of supermassive black holes. Others are isolated features, illuminating winds and intergalactic shock waves in the surrounding plasma. Other types of science enriched by the MGCLS include the regulation of star formation in galaxies, the physical processes of jet interactions, the study of faint cooler hydrogen gas – the fuel of stars – in a variety of environments, and yet unknown investigations to be facilitated by serendipitous discoveries.

The MGCLS has revealed several new systems hosting faint sources on large scales. Here we see radio evidence of a powerful merger taking place between two or more massive groups of gas and galaxies. These structures (a so-called ‘halo’ near the center and two ‘relics’ surrounding it are seen in the galaxy cluster MCXC J0352.4-7401) trace the positions and strengths of cosmic magnetic fields and electron populations travelling near the speed of light. This MeerKAT image spans approximately 10 million light-years at the distance of the cluster, and is sprinkled with point-like radio emission from even more distant Milky Way-like galaxies. Adapted from K. Knowles et al., The MeerKAT Galaxy Cluster Legacy Survey. I. Survey Overview and Highlights (Astronomy & Astrophysics, in press). Image credit: SARAO.

The MGCLS has produced detailed images of the extremely faint radio sky, while surveying a very large volume of space. “That’s what’s already enabled us to serendipitously discover rare kinds of galaxies, interactions, and diffuse features of radio emission, many of them quite beautiful,” explained Dr. Knowles. But this is only the beginning.

A number of additional studies delving more deeply into some of the initial discoveries are already underway by members of the MGCLS team. Beyond that, the richness of the science resulting from the MGCLS is expected to grow over the coming years, as astronomers from around the world download the data from the SARAO MeerKAT archive, and probe it to answer their own questions.

Two giant radio galaxies (more than one million light-years from end to end) at the center of a large group of galaxies in the cluster Abell 194, revealing the presence of relatively narrow magnetic filaments in the region, as well as complex interactions between the radio emission from the two galaxies. The MeerKAT radio image is shown in orange, with an optical image dominated by normal galaxies shown in white. Adapted from K. Knowles et al., The MeerKAT Galaxy Cluster Legacy Survey. I. Survey Overview and Highlights (Astronomy & Astrophysics, in press). Image credit: SARAO, SDSS.

The Collaboration

It takes more than a village to create this astronomical bonanza. MeerKAT, the South African SKA precursor that will be integrated into the SKA1-Mid telescope in the coming decade, was conceived, designed, and built over 15 years through the dedicated effort of hundreds of people in South African research organizations, industry, universities, and government. Some 100 of these colleagues that built, operate and maintain MeerKAT are co-authors of the MGCLS paper.

A team of 40 South African and international scientists was involved in the detailed analysis that is presented in the paper and associated data release. They represent 19 institutions, including 10 in South Africa: The University of KwaZulu-Natal [Inyucesi YAKWAZULU_NATALI (SA), The Rhodes University (SA), SARAO – South African Radio Astronomy Observatory (SA), The University of the Witwatersrand (SA), The University of Pretoria (SA), The University of Cape Town (SA),The North-West University (SA), The University of the Western Cape (SA), The African Institute for Mathematical Sciences (SA), The Inter-University Institute for Data Intensive Astronomy (SA); The National Radio Astronomy Observatory (US), The University of Minnesota (US), The INAF Italian National Institute for Astrophysics [Istituto Nazionale di Astrofisica] (IT), York University, The University of Hamburg [Universität Hamburg](DE), The University Of Nigeria [Nsukka](NRA), The Naval Research Laboratory (US), The Rhenish Friedrich Wilhelm University of Bonn[Rheinische Friedrich-Wilhelms-Universität Bonn](DE), La Sapienza University of Rome [Sapienza Università di Roma](IT).

The Telescope and Observatory

The MeerKAT telescope is operated by the South African Radio Astronomy Observatory, which is a facility of the National Research Foundation, an agency of the Department of Science and Innovation.

See the full article here .

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SKA ASKAP Pathfinder Radio Telescope

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

SKA Murchison Widefield Array (AU), Boolardy station in outback Western Australia, at the Murchison Radio-astronomy Observatory (MRO), on the traditional lands of the Wajarri peoples.

SKA Hera at SKA South Africa.

SKA Pathfinder – LOFAR location at Potsdam via Google Images

About SKA South Africa (SA)

MeerKAT, originally the Karoo Array Telescope, is a radio telescope consisting of 64 antennas in the Northern Cape of South Africa. In 2003, South Africa submitted an expression of interest to host the Square Kilometre Array (SKA) Radio Telescope in Africa, and the locally designed and built MeerKAT was incorporated into the first phase of the SKA.

About SKA

The Square Kilometre Arraywill 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 Netherlands Institute for Radio Astronomy (ASTRON) (NL) : “Aurorae discovered on distant stars suggest hidden planets”

From Netherlands Institute for Radio Astronomy (ASTRON) (NL)

11 October 2021

Using the world’s most powerful radio telescope, LOFAR [below], scientists have discovered stars unexpectedly blasting out radio waves, possibly indicating the existence of hidden planets.

Searching for red dwarfs

Leiden University [Universiteit Leiden](NL)’s Dr Joseph Callingham and his colleagues have been searching for aurorae from exoplanets using the Low Frequency Array (LOFAR), the world’s most powerful radio telescope. “We’ve discovered signals from 19 distant red dwarf stars, four of which are best explained by the existence of planets orbiting them,” Dr Callingham said. “We’ve long known that the planets of our own solar system emit powerful radio waves as their magnetic fields interact with the solar wind. This same process drives the beautiful aurorae we see at the poles of Earth.

Artist impression of a red-dwarf star’s magnetic interaction with its exoplanet. Credit: Danielle Futselaar (artsource.nl)

“However, it is only with LOFAR have we had the sensitivity to find auroral emission outside our Solar System. This is an incredibly powerful tool to help find planets outside our Solar System and to determine their magnetic fields.” LOFAR was designed, built and is presently operated by ASTRON, the Netherlands Institute for Radio Astronomy, its core is situated in Exloo, the Netherlands.

Using the world’s most powerful radio telescope, LOFAR, scientists have discovered stars unexpectedly blasting out radio waves, possibly indicating the existence of hidden planets.

Dr Harish Vedantham at ASTRON, the Netherlands Institute for Radio Astronomy, co-author of the paper, said that the team is confident these signals are coming from the magnetic connection of the stars and unseen orbiting planets, similar to the interaction between Jupiter and its moon Io. “Our own Earth has aurorae, commonly recognised here as the northern and southern lights. These beautiful aurorae also emit powerful radio waves – this is from the interaction of the planet’s magnetic field with the solar wind,” he said. “But in the case of aurorae from Jupiter, they’re much stronger as its volcanic moon Io is blasting material out into space, filling Jupiter’s environment with particles that drive unusually powerful aurorae.

“Our model for this radio light from our stars is a scaled-up version of Jupiter and Io, with an exoplanet enveloped in the magnetic field of a star, feeding material into vast currents that similarly power bright aurorae on the star itself.

“It’s a spectacle that has attracted our attention from lightyears away.”

The hunt for exo-aurora’s.
Using the world’s most powerful radio telescope, LOFAR, scientists have discovered stars unexpectedly blasting out radio waves, possibly indicating the existence of hidden planets.

Future observations with the SKA Square Kilometre Array (AU)(SA)

The team are now investigating the direct presence of the planets around the star using optical telescopes and searching for periodicity in the radio light. “The radio light should turn on and off like a lighthouse,” Dr Callingham said “and we hope to see that periodicity in new LOFAR data.”

The discoveries with LOFAR are just the beginning, but the telescope only has the capacity to monitor stars that are relatively nearby, up to 165 lightyears away. With the next-generation Square Kilometre Array radio telescope finally under construction, switching on in 2029, the team predict they will be able to see hundreds of relevant stars out to much greater distances.

SKA ASKAP Pathfinder Radio Telescope

SKA Square Kilometre Array low frequency at Murchison Widefield Array, Boolardy station in outback Western Australia on the traditional lands of the Wajarri peoples

SKA SARAO Meerkat telescope , 90 km outside the small Northern Cape town of Carnarvon, SA.
(SA)

This work demonstrates that radio astronomy is on the cusp of revolutionising our understanding of planets outside our Solar System.

Science paper:
Nature Astronomy

See the full article here .

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Please help promote STEM in your local schools.

Stem Education Coalition

ASTRON is the ASTRON-Netherlands Institute for Radio Astronomy [Nederlands Instituut voor Radioastronomie] (NL). Its main office is in Dwingeloo in the Dwingelderveld National Park in the province of Drenthe. ASTRON is part of Netherlands Organisation for Scientific Research (NWO).

ASTRON’s main mission is to make discoveries in radio astronomy happen, via the development of new and innovative technologies, the operation of world-class radio astronomy facilities, and the pursuit of fundamental astronomical research. Engineers and astronomers at ASTRON have an outstanding international reputation for novel technology development, and fundamental research in galactic and extra-galactic astronomy. Its main funding comes from NWO.

ASTRON’s programme has three principal elements:

The operation of front line observing facilities, including especially the Westerbork Synthesis Radio Telescope and LOFAR,
The pursuit of fundamental astronomical research using ASTRON facilities, together with a broad range of other telescopes around the world and space-borne instruments (e.g. Sptizer, HST etc.)
A strong technology development programme, encompassing both innovative instrumentation for existing telescopes and the new technologies needed for future facilities.

In addition, ASTRON is active in the international science policy arena and is one of the leaders in the international SKA project. The Square Kilometre Array will be the world’s largest and most sensitive radio telescope with a total collecting area of approximately one square kilometre. The SKA will be built in Southern Africa and in Australia. It is a global enterprise bringing together 11 countries from the 5 continents.

Radio telescopes

ASTRON operates the Westerbork Synthesis Radio Telescope (WSRT), one of the largest radio telescopes in the world. The WSRT and the International LOFAR Telescope (ILT) are dedicated to explore the universe at radio frequencies ranging from 10 MHz to 8 GHz.

Westerbork Synthesis Radio Telescope, an aperture synthesis interferometer near World War II Nazi detention and transit camp Westerbork, north of the village of Westerbork, Midden-Drenthe, in the northeastern Netherlands.

In addition to its use as a stand-alone radio telescope, the Westerbork array participates in the European Very Long Baseline Interferometry Network (EVN) of radio telescopes.

ASTRON is the host institute for the Joint Institute for VLBI in Europe (JIVE).

European Very Long Baseline Interferometry Network

Its primary task is to operate the EVN MkIV VLBI Data Processor (correlator). JIVE also provides a high-level of support to astronomers and the Telescope Network. ASTRON also hosts the NOVA Optical/ Infrared instrumentation group.

LOFAR is a radio telescope composed of an international network of antenna stations and is designed to observe the universe at frequencies between 10 and 250 MHz. Operated by ASTRON (NL), the network includes stations in the Netherlands, Germany, Sweden, the U.K., France, Poland and Ireland.

ASTRON Institute for Radio Astronomy(NL) LOFAR Radio Antenna Bank(NL)

From Curtin University (AU) : “The future of extraterrestrial intelligence”

From Curtin University (AU)

3 September 2021

How would you feel if, after many decades of searching, we finally found signs of extraterrestrial intelligence?

Would you be consumed by wonder and excitement, or does the thought of making contact with an unknown life force somewhere out there in the universe fill you with fear and trepidation?

And what impact would this discovery have on us collectively – would it unite us or divide us here on Earth?

“Maybe the search for extraterrestrials actually tells us more about ourselves than anything else,” says world-renowned astronomer and deputy executive director of the International Centre for Radio Astronomy Research, Professor Steven Tingay, who has been pondering these and other weighty existential questions in the course of his research.

Tingay and his CSIRO colleague Dr Chenoa Tremblay have been involved in the deepest and broadest search yet for signs of alien life, thanks to the capabilities offered by the Murchison Widefield Array (MWA) – the highly sensitive, low frequency radio telescope with a fantastically wide field of view that is supporting a trove of new scientific endeavours from its whisper-quiet location in inland Western Australia.

SKA Square Kilometre Array low frequency at Murchison Widefield Array, Boolardy station in outback Western Australia on the traditional lands of the Wajarri peoples

The Murchison Radio-astronomy Observatory,on the traditional lands of the Wajarri peoples, in outback Western Australia will house up to 130,000 antennas like these and the associated advanced technologies.

SKA Murchison Widefield Array (AU), Boolardy station in outback Western Australia, at the Murchison Radio-astronomy Observatory (MRO), on the traditional lands of the Wajarri peoples.

EDGES telescope in a radio quiet zone at the Murchison Radio-astronomy Observatory in Western Australia, on the traditional lands of the Wajarri peoples.

So far, no signals have been detected to suggest we are not alone. But with the MWA now allowing much-expanded searches to be conducted alongside other astrophysical investigations, the search for extraterrestrial intelligence – commonly referred to as SETI – is definitely ramping up.

For example, it will no doubt add to fresh questions about our cosmic exclusivity generated by NASA’s latest mission to Mars, where the Perseverance rover is collecting rock and soil samples that will be probed for signs of ancient microbial life.

In 2018, the MWA was used to scan part of the Vela constellation, known to cover at least 10 million star systems. Within this field are six known exoplanets: planets that orbit around other stars, like the Earth orbits around the Sun, that could potentially offer the right conditions for hosting life. Through this and two previous surveys, Tingay and Tremblay examined 75 known exoplanets, searching for narrow-band signals consistent with radio transmissions from intelligent civilisations, with a further 144 exoplanets examined in research to be published soon.

Fortuitously, the MWA allows the search for extraterrestrial intelligence to piggyback onto science that is already taking place – offering, as Tingay describes it, “two bits of science for one”. As part of her PhD research, Chenoa was using the radio telescope to observe molecular signatures from stars, gas and dust in our galaxy in the hopes of detecting the complex molecules that are the precursor to life. The pair then realised that these data could be simultaneously used for the search for radio signals from advanced civilisations.

“It’s a very high-return, low-effort route at this stage, which means that if you strike it lucky it hasn’t really cost you all that much along the way,” explains Tingay. “So that’s almost a perfect scenario for science.”

So what exactly are they looking for in their MWA surveys?

“We’re not one hundred per cent sure,” admits Tremblay.

“It’s like asking a toddler to go and find an object in the house and they very excitedly go and run around and look under the couch and then come back with big eyes and go, ‘What does it look like?’

“In general, we’re looking for intense signals that show up in very narrow wavelength ranges, and it could be anywhere within the electromagnetic spectrum. We use models from our understanding of the cosmos and what the signals have looked like so far to narrow down the search.

While the 2018 survey was far more comprehensive than ever before, Tingay is keen to point out that it was still just a drop in the ocean.

“Our galaxy contains billions and billions of stars, so 10 million out of multiple billions is a very small fraction,” he explains.

“If that entire search space was represented by the Earth’s oceans, we’re talking about searching about a swimming pool’s worth of water out of the ocean. Having said that, what we did was a hundred times better than anyone had done previously – and the previous best was also us!

“So what we’re doing is proving up techniques that will allow us to go further and deeper as we develop more powerful telescopes. And the next step in that progression is the Square Kilometre Array.”

The MWA is effectively the warm-up act for the Square Kilometre Array, which has started its construction phase in Western Australia and South Africa, following more than a decade of design and engineering work by hundreds of experts from more than a dozen countries.

SKA-Square Kilometer Array

[See MWA low frequency above]

SKA ASKAP Pathfinder Radio Telescope

SKA- South Africa

SKA SARAO Meerkat telescope , 90 km outside the small Northern Cape town of Carnarvon, SA.
(SA)

This global mega science project will deliver the two largest and most complex networks of radio telescopes ever built, designed to unlock some of the most fascinating secrets of our Universe – and it no doubt has SETI enthusiasts very, very excited.

Asked to sum up his own reaction should this new frontier of astronomy confirm signs of extraterrestrial intelligence sometime soon, Tingay is quick to respond: “I’ll rush to the telescope to get more data!”
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The MWA, SKA and SARAO are not alone in the search for E.T.

Breakthrough Listen Project

UC Observatories Lick Automated Planet Finder fully robotic 2.4-meter optical telescope at Lick Observatory, situated on the summit of Mount Hamilton, east of San Jose, California, USA.

Green Bank Radio Telescope, West Virginia, USA, now the center piece of the Green Bank Observatory(US), being cut loose by the National Science Foundation(US), supported by Breakthrough Listen Project, West Virginia University, and operated by the nonprofit Associated Universities, Inc..

CSIRO-Commonwealth Scientific and Industrial Research Organisation (AU) Parkes Observatory [ Murriyang, the traditional Indigenous name] , located 20 kilometres north of the town of Parkes, New South Wales, Australia, 414.80m above sea level.

SKA SARAO Meerkat telescope(SA) 90 km outside the small Northern Cape town of Carnarvon, SA.

Newly added

University of Arizona Veritas Four Čerenkov telescopes A novel gamma ray telescope under construction at the CfA Fred Lawrence Whipple Observatory (US), Mount Hopkins, Arizona (US), altitude 2,606 m 8,550 ft. A large project known as the Čerenkov Telescope Array, composed of hundreds of similar telescopes to be situated at Roque de los Muchachos Observatory [Instituto de Astrofísica de Canarias ](ES) in the Canary Islands and Chile at European Southern Observatory Cerro Paranal(EU) site. The telescope on Mount Hopkins will be fitted with a prototype high-speed camera, assembled at the University of Wisconsin–Madison (US) and capable of taking pictures at a billion frames per second. Credit: Vladimir Vassiliev. _____________________________________________________________________________________

See the full article here .

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Please help promote STEM in your local schools.

Stem Education Coalition

Curtin University (AU) (formerly known as Curtin University of Technology and Western Australian Institute of Technology) is an Australian public research university based in Bentley and Perth, Western Australia. The university is named after the 14th Prime Minister of Australia, John Curtin, and is the largest university in Western Australia, with over 58,000 students (as of 2016).

Curtin would like to pay respect to the indigenous members of our community by acknowledging the traditional owners of the land on which the Perth campus is located, the Wadjuk people of the Nyungar Nation; and on our Kalgoorlie campus, the Wongutha people of the North-Eastern Goldfields.

Curtin was conferred university status after legislation was passed by the Parliament of Western Australia in 1986. Since then, the university has been expanding its presence and has campuses in Singapore, Malaysia, Dubai and Mauritius. It has ties with 90 exchange universities in 20 countries. The University comprises five main faculties with over 95 specialists centres. The University formerly had a Sydney campus between 2005 & 2016. On 17 September 2015, Curtin University Council made a decision to close its Sydney campus by early 2017.

Curtin University is a member of Australian Technology Network (ATN), and is active in research in a range of academic and practical fields, including Resources and Energy (e.g., petroleum gas), Information and Communication, Health, Ageing and Well-being (Public Health), Communities and Changing Environments, Growth and Prosperity and Creative Writing.

It is the only Western Australian university to produce a PhD recipient of the AINSE gold medal, which is the highest recognition for PhD-level research excellence in Australia and New Zealand.

Curtin has become active in research and partnerships overseas, particularly in mainland China. It is involved in a number of business, management, and research projects, particularly in supercomputing, where the university participates in a tri-continental array with nodes in Perth, Beijing, and Edinburgh. Western Australia has become an important exporter of minerals, petroleum and natural gas. The Chinese Premier Wen Jiabao visited the Woodside-funded hydrocarbon research facility during his visit to Australia in 2005.

From Swiss Federal Institute of Technology in Zürich [ETH Zürich] [Eidgenössische Technische Hochschule Zürich](CH): “Looking deep into the universe”

From Swiss Federal Institute of Technology in Zürich [ETH Zürich] [Eidgenössische Technische Hochschule Zürich](CH)

31.05.2021
Felix Würsten

How is matter distributed within our universe? And what is the mysterious substance known as dark energy made of? HIRAX, a new large telescope array comprising hundreds of small radio telescopes, should provide some answers. Among those instrumental in developing the system are physicists from ETH Zürich.

SKA HIRAX prototype dishes at Hartebeesthoek Astronomy Observatory near Johannesburg,SA

Hartebeesthoek Radio Astronomy Observatory, located west of Johannesburg South Africa.
How the final expansion of the HIRAX telescope in the Karoo semidesert in South Africa should look once completed. (Image: Cynthia Chiang / HIRAX.)

“It’s an exciting project,” says Alexandre Refregier, Professor of Physics at ETH Zürich, as he considers the futuristic-​looking visualisation from South Africa. The image shows a scene in the middle of the Karoo semidesert, far away from larger settlements, with rows upon rows of more than 1,000 parabolic reflectors all directed towards the same point. At first glance, one might assume this is a solar power station, but it’s actually a large radio telescope that over the coming years should provide cosmologists with new insights into the makeup and history of our universe.

Key element: hydrogen

HIRAX stands for Hydrogen Intensity and Real-​time Analysis eXperiment and marks the start of a new chapter in the exploration of the universe. The new large telescope will collect radio signals within a frequency range of 400 to 800 MHz. These signals will make it possible to measure the distribution of hydrogen in the universe on a large scale. “If we can use hydrogen, the most common element in the universe, to discover how matter is distributed in space, we could then draw conclusions about what dark matter and dark energy are made of,” Refregier explains.

Dark Energy and Dark Matter are two mysterious components that together make up the vast majority of the universe. They play a major role in the formation of structures and in the universe’s accelerated expansion. But experts remain puzzled about exactly what dark energy and dark matter are made of. HIRAX should help home in on the precise nature of these two components. The researchers also hope that the new system will deliver insights into fast radio bursts and pulsars.

Combining hundreds of individual signals

Not only will Refregier and his team be involved in the scientific analysis of the data, the professor is also helping to develop the new system together with his postdoc Devin Crichton and engineer Thierry Viant. “HIRAX is a remarkable undertaking, not just from a scientific point of view, but also because it represents a significant technological challenge,” Refregier says. As part of their subproject in collaboration with scientists from the University of Geneva [Université de Genève](CH), the ETH researchers are developing what’s known as a digital correlator, which will combine the signals recorded by each of the approximately six-​metre telescopes. “Rather than consisting of a single large telescope, the HIRAX array is made up of numerous smaller radio telescopes that are correlated with each other,” Refregier says. “This enables us to build a telescope with a collection surface and resolution much greater than a measuring device with only one parabolic reflector.”

Tested in Switzerland

The physicists first tested the technology for the digital corrector in Switzerland using a pilot system. To do so, they used the two historic radio telescopes housed at the Bleien facility in the Swiss canton of Aargau. They will now use the results of these tests to develop a digital corrector capable of linking 256 reflectors. “The HIRAX telescope is being set up in stages, which allows us to develop and refine the technology we need as we go along,” Refregier says. The funding required for this subproject was recently secured.

For their digital correlator, the ETH Zurich physicists are using high-​performance graphics processing units that were originally developed for video and gaming applications. The researchers are also breaking new ground when it comes to calibration. To synchronise the measurement signals received by the individual antennas, they use a radio signal transmitted by a drone. It is crucial to pinpoint the position of these signals so that the telescope can then provide the required precision.

An ideal location

It’s no accident that the HIRAX telescope is being installed in the Karoo semidesert. As a protected area, it is still largely free of disruptive signals from mobile communications antennas. “It’s actually quite ironic,” Refregier says. “On the one hand, mobile communications technology is a massive help in developing telescopes. On the other, that same technology makes life difficult for radio astronomers because mobile communications antennas transmit within similar frequency ranges.

Another reason why the Karoo region is an ideal location is that this is also where part of the planned Square Kilometre Array will be erected.

SKA- South Africa

Once completed, this will be the world’s largest radio telescope, connecting systems in South Africa and Australia and representing yet another giant leap forward in radio astronomy. “Despite its remote position, the Karoo location is well connected by power and data lines,” Refregier says. In this respect, the undertaking presents a challenge because the new telescope will generate 6.5 terabytes of data every second. “This is why we’re going to install the digital corrector directly on site, so that the amount of data can first be reduced before it is sent somewhere else for further processing,” Refregier says.

Opening the door for the next large-​scale project

A collaboration among numerous other universities from different countries, the HIRAX project is also important with respect to research policy. First, it strengthens the collaboration between South Africa and Switzerland, enabling young scientists from the former to conduct research in the latter. Second, Refregier says he is grateful that the work we are doing on the development of HIRAX is opening the door to Switzerland’s participation in the Square Kilometre Array: “This means that we can do our part to ensure that Swiss universities are involved in this pioneering project and can keep pace with the latest developments in radio astronomy.”

_____________________________________________________________________________________
Dark Energy Survey

Dark Energy Camera [DECam] built at DOE’s Fermi National Accelerator Laboratory(US),

]

NOIRLab National Optical Astronomy Observatory(US) Cerro Tololo Inter-American Observatory(CL) Victor M Blanco 4m Telescope which houses the Dark-Energy-Camera – DECam at Cerro Tololo, Chile at an altitude of 7200 feet

Timeline of the Inflationary Universe WMAP

The Dark Energy Survey (DES) is an international, collaborative effort to map hundreds of millions of galaxies, detect thousands of supernovae, and find patterns of cosmic structure that will reveal the nature of the mysterious dark energy that is accelerating the expansion of our Universe. DES began searching the Southern skies on August 31, 2013.

According to Einstein’s theory of General Relativity, gravity should lead to a slowing of the cosmic expansion. Yet, in 1998, two teams of astronomers studying distant supernovae made the remarkable discovery that the expansion of the universe is speeding up. To explain cosmic acceleration, cosmologists are faced with two possibilities: either 70% of the universe exists in an exotic form, now called dark energy, that exhibits a gravitational force opposite to the attractive gravity of ordinary matter, or General Relativity must be replaced by a new theory of gravity on cosmic scales.

DES is designed to probe the origin of the accelerating universe and help uncover the nature of dark energy by measuring the 14-billion-year history of cosmic expansion with high precision. More than 400 scientists from over 25 institutions in the United States, Spain, the United Kingdom, Brazil, Germany, Switzerland, and Australia are working on the project. The collaboration built and is using an extremely sensitive 570-Megapixel digital camera, DECam, mounted on the Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory, high in the Chilean Andes, to carry out the project.

Over six years (2013-2019), the DES collaboration used 758 nights of observation to carry out a deep, wide-area survey to record information from 300 million galaxies that are billions of light-years from Earth. The survey imaged 5000 square degrees of the southern sky in five optical filters to obtain detailed information about each galaxy. A fraction of the survey time is used to observe smaller patches of sky roughly once a week to discover and study thousands of supernovae and other astrophysical transients.
_____________________________________________________________________________________

Dark Matter Background
Fritz Zwicky discovered Dark Matter in the 1930s when observing the movement of the Coma Cluster., Vera Rubin a Woman in STEM denied the Nobel, some 30 years later, did most of the work on Dark Matter.

Fritz Zwicky from http:// palomarskies.blogspot.com.

Coma cluster via NASA/ESA Hubble.

In modern times, it was astronomer Fritz Zwicky, in the 1930s, who made the first observations of what we now call dark matter. His 1933 observations of the Coma Cluster of galaxies seemed to indicated it has a mass 500 times more than that previously calculated by Edwin Hubble. Furthermore, this extra mass seemed to be completely invisible. Although Zwicky’s observations were initially met with much skepticism, they were later confirmed by other groups of astronomers.
Thirty years later, astronomer Vera Rubin provided a huge piece of evidence for the existence of dark matter. She discovered that the centers of galaxies rotate at the same speed as their extremities, whereas, of course, they should rotate faster. Think of a vinyl LP on a record deck: its center rotates faster than its edge. That’s what logic dictates we should see in galaxies too. But we do not. The only way to explain this is if the whole galaxy is only the center of some much larger structure, as if it is only the label on the LP so to speak, causing the galaxy to have a consistent rotation speed from center to edge.
Vera Rubin, following Zwicky, postulated that the missing structure in galaxies is dark matter. Her ideas were met with much resistance from the astronomical community, but her observations have been confirmed and are seen today as pivotal proof of the existence of dark matter.

Astronomer Vera Rubin at the Lowell Observatory in 1965, worked on Dark Matter (The Carnegie Institution for Science).

Vera Rubin measuring spectra, worked on Dark Matter (Emilio Segre Visual Archives AIP SPL).

Vera Rubin, with Department of Terrestrial Magnetism (DTM) image tube spectrograph attached to the Kitt Peak 84-inch telescope, 1970. https://home.dtm.ciw.edu.

_____________________________________________________________________________________

See the full article here .

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Please help promote STEM in your local schools.

Stem Education Coalition

Swiss Federal Institute of Technology in Zürich [ETH Zürich] [Eidgenössische Technische Hochschule Zürich](CH) is a public research university in the city of Zürich, Switzerland. Founded by the Swiss Federal Government in 1854 with the stated mission to educate engineers and scientists, the school focuses exclusively on science, technology, engineering and mathematics. Like its sister institution Swiss Federal Institute of Technology in Lausanne [EPFL-École Polytechnique Fédérale de Lausanne](CH) , it is part of the Swiss Federal Institutes of Technology Domain (ETH Domain)) , part of the Swiss Federal Department of Economic Affairs, Education and Research.

The university is an attractive destination for international students thanks to low tuition fees of 809 CHF per semester, PhD and graduate salaries that are amongst the world’s highest, and a world-class reputation in academia and industry. There are currently 22,200 students from over 120 countries, of which 4,180 are pursuing doctoral degrees. In the 2021 edition of the QS World University Rankings ETH Zürich is ranked 6th in the world and 8th by the Times Higher Education World Rankings 2020. In the 2020 QS World University Rankings by subject it is ranked 4th in the world for engineering and technology (2nd in Europe) and 1st for earth & marine science.

As of November 2019, 21 Nobel laureates, 2 Fields Medalists, 2 Pritzker Prize winners, and 1 Turing Award winner have been affiliated with the Institute, including Albert Einstein. Other notable alumni include John von Neumann and Santiago Calatrava. It is a founding member of the IDEA League and the International Alliance of Research Universities (IARU) and a member of the CESAER network.

ETH Zürich was founded on 7 February 1854 by the Swiss Confederation and began giving its first lectures on 16 October 1855 as a polytechnic institute (eidgenössische polytechnische Schule) at various sites throughout the city of Zurich. It was initially composed of six faculties: architecture, civil engineering, mechanical engineering, chemistry, forestry, and an integrated department for the fields of mathematics, natural sciences, literature, and social and political sciences.

It is locally still known as Polytechnikum, or simply as Poly, derived from the original name eidgenössische polytechnische Schule, which translates to “federal polytechnic school”.

ETH Zürich is a federal institute (i.e., under direct administration by the Swiss government), whereas the University of Zürich is a cantonal institution. The decision for a new federal university was heavily disputed at the time; the liberals pressed for a “federal university”, while the conservative forces wanted all universities to remain under cantonal control, worried that the liberals would gain more political power than they already had. In the beginning, both universities were co-located in the buildings of the University of Zürich.

From 1905 to 1908, under the presidency of Jérôme Franel, the course program of ETH Zürich was restructured to that of a real university and ETH Zürich was granted the right to award doctorates. In 1909 the first doctorates were awarded. In 1911, it was given its current name, Eidgenössische Technische Hochschule. In 1924, another reorganization structured the university in 12 departments. However, it now has 16 departments.

ETH Zürich, EPFL (Swiss Federal Institute of Technology in Lausanne) [École polytechnique fédérale de Lausanne](CH), and four associated research institutes form the “ETH Domain” with the aim of collaborating on scientific projects.

Reputation and ranking

ETH Zürich is ranked among the top universities in the world. Typically, popular rankings place the institution as the best university in continental Europe and ETH Zürich is consistently ranked among the top 1-5 universities in Europe, and among the top 3-10 best universities of the world.

Historically, ETH Zürich has achieved its reputation particularly in the fields of chemistry, mathematics and physics. There are 32 Nobel laureates who are associated with ETH Zürich, the most recent of whom is Richard F. Heck, awarded the Nobel Prize in chemistry in 2010. Albert Einstein is perhaps its most famous alumnus.

In 2018, the QS World University Rankings placed ETH Zürich at 7th overall in the world. In 2015, ETH Zürich was ranked 5th in the world in Engineering, Science and Technology, just behind the Massachusetts Institute of Technology(US), Stanford University(US) and University of Cambridge(UK). In 2015, ETH Zürich also ranked 6th in the world in Natural Sciences, and in 2016 ranked 1st in the world for Earth & Marine Sciences for the second consecutive year.

In 2016, Times Higher Education WorldUniversity Rankings ranked ETH Zürich 9th overall in the world and 8th in the world in the field of Engineering & Technology, just behind the Massachusetts Institute of Technology(US), Stanford University(US), California Institute of Technology(US), Princeton University(US), University of Cambridge(UK), Imperial College London(UK) and

From Nagoya University [名古屋大学] (JP) : “Plasma jets reveal magnetic fields far far away”

From Nagoya University [名古屋大学] (JP)

May 21, 2021

Tsutomu T. Takeuchi
Graduate School of Science, Nagoya University
takeuchi.tsutomu@g.mbox.nagoya-u.ac.jp

A black hole (marked by the red x) at the centre of galaxy MRC 0600-399 emits a jet of particles that bends into a ‘double-scythe’ T-shape that follows the magnetic field lines at the galaxy subcluster’s boundary.
(Image Credit: Modified from Chibueze, Sakemi, Ohmura et al. (2021) Nature Fig. 1(b).)

For the first time, researchers have observed plasma jets interacting with magnetic fields in a massive galaxy cluster 600 million light years away, thanks to the help of radio telescopes and supercomputer simulations. The findings, published in the journal Nature, can help clarify how such galaxy clusters evolve.

Galaxy clusters can contain up to thousands of galaxies bound together by gravity.

Laniakea supercluster. From Nature: The Laniakea supercluster of galaxies. Milky Way is the red dot. Credit: R. Brent Tully, Hélène Courtois, Yehuda Hoffman & Daniel Pomarède at http://www.nature.com/nature/journal/v513/n7516/full/nature13674.html.

Abell 3376 is a huge cluster forming as a result of a violent collision between two sub-clusters of galaxies. Very little is known about the magnetic fields that exist within this and similar galaxy clusters.

National Aeronautics Space Agency (US) – Galaxy Cluster Abell 3376

“It is generally difficult to directly examine the structure of intracluster magnetic fields,” says Nagoya University astrophysicist Tsutomu Takeuchi, who was involved in the research. “Our results clearly demonstrate how long-wavelength radio observations can help explore this interaction.”

An international team of scientists have been using the MeerKAT radio telescope in the Northern Cape of South Africa to learn more about Abell 3376’s huge magnetic fields.

SKA SARAO Meerkat telescope , 90 km outside the small Northern Cape town of Carnarvon, SA.
(SA)

One of the telescope’s very high-resolution images revealed something unexpected: plasma jets emitted by a supermassive black hole in the cluster bend to form a unique T-shape as they extend outwards for distances as far as 326,156 light years away. The black hole is in galaxy MRC 0600-399, which is near the centre of Abell 3376.

The team combined their MeerKAT radio telescope data with X-ray data from the European Space Agency’s space telescope XXM-Newton to find that the plasma jet bend occurs at the boundary of the subcluster in which MRC 0600-399 exists.

European Space Agency [Agence spatiale européenne][Europäische Weltraumorganisation](EU)/XMM Newton X-ray telescope (EU).

“This told us that the plasma jets from MRC 0600-399 were interacting with something in the heated gas, called the intracluster medium, that exists between the galaxies within Abell 3376,” explains Takeuchi.

To figure out what was happening, the team conducted 3D ‘magnetohydrodynamic’ simulations using the world’s most powerful supercomputer in the field of astronomical calculations, ATERUI II, located at the National Astronomical Observatory of Japan [国立天文台](JP).

NAOJ ATERUI II Cray XC50 supercomputer located at the National Astronomical Observatory [国立天文台; kokuritsu tenmondai] (JP) (NAOJ).

The simulations showed that the jet streams emitted by MRC 0600-399’s black hole eventually reach and interact with magnetic fields at the border of the galaxy subcluster. The jet stream compresses the magnetic field lines and moves along them, forming the characteristic T-shape.

“This is the first discovery of an interaction between cluster galaxy plasma jets and intracluster magnetic fields,” says Takeuchi.

An international team has just begun construction of what is planned to be the world’s largest radio telescope, called the Square Kilometre Array (SKA).

SKA-Square Kilometer Array

SKA- South Africa

“New facilities like the SKA are expected to reveal the roles and origins of cosmic magnetism and even to help us understand how the universe evolved,” says Takeuchi. “Our study is a good example of the power of radio observation, one of the last frontiers in astronomy.”

See the full article here.

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Please help promote STEM in your local schools.

Stem Education Coalition

Nagoya University [名古屋大学] (JP), is a Japanese national university located in Chikusa-ku, Nagoya. It is the last Imperial University in Japan, one of the Designated National University and selected as a Top Type university of Top Global University Project by the Japanese government. It is the 3rd highest ranked higher education institution in Japan (72nd worldwide).

The University is the birthplace of the Sakata School of physics and the Hirata School of chemistry. As of 2014, six Nobel Prize winners have been associated with Nagoya University, the third most in Japan and Asia behind Kyoto University [京都大学, Kyōto daigaku](JP) and the U Tokyo [(東京大学] (JP).

Nagoya University traces its roots back to 1871 when it was a temporary medical school. In 1939 it became Nagoya Imperial University [名古屋帝国大学]. In 1947 it was renamed Nagoya University [名古屋大学], and became a Japanese national university. In 2014, according to the reform measures of the Ministry of Education, Culture, Sports, Science and Technology, all Japanese national universities became National University Corporation [国立大学法人]. The university has a profound tradition of physics and chemistry. Many world-class scientific research achievements include Sakata model, PMNS matrix, Okazaki fragment, Noyori asymmetric hydrogenation, and Blue LED were born in Nagoya University.

In the 20th century, NU’s Kuno Yasu and Katsunuma Seizō were nominated for the Nobel Prize in Physiology or Medicine, Yoshio Ohnuki was nominated for the Nobel Prize in Physics. In the 21st century, NU peoples account for half of the total number of Japanese Nobel Prize winners (up to 2014). Among the six winners of the Nobel Prize in Chemistry and the Physics, there are three professors and five alumni. The number of winners is the third among Japanese universities. In addition, the team under Professor Morishima Kunihiro participated in the Scanpyramids project by using special nuclear emulsion plates. This led to the discovery in 2017 of new chambers in the great pyramid.

In March 2012, Nagoya University played host to the International Symposium on Innovative Nanobiodevices. Three years later, NU was selected as one of the five champion universities for gender equality by the United Nations Entity for Gender Equality and the Empowerment of Women.

In March 2018, Nagoya University was selected as one of top five Designated National University Corporation [指定国立大学法人]. In order to become the largest national higher education corporation in Japan, the Tokai National Higher Education and Research System [国立大学法人東海国立大学機構] established by integrating with Gifu University in April 2020, both are major universities in Central Japan.

From Curtin University (AU) via phys.org : “How scientists are tuning in to the universe-man”

From Curtin University (AU)

via

phys.org

May 13, 2021

An artist’s impression of a pulsar. Credit: International Centre for Radio Astronomy Research /Curtin University (AU)

You’re driving down the freeway listening to the radio, but you’re getting static. Enjoy it. That’s the sounds of the universe.

You’re driving down the freeway listening to the radio. Unfortunately, the radio is picking up some static. Sounds a bit rough, doesn’t it?

It may surprise you to learn that static is actually the grand opera of the universe—stars, pulsars, galaxies—all of which blast out radio waves and have been doing so for billions of years.

Yup, the car radio in your 2002 Honda Civic is tuned in to the universe, man.

But while we all may be able to tune in to Cosmic FM, not all of us can make sense of the noise.

That’s where Professor Steven Tingay comes in. He’s the Executive Director of the Curtin University CIRA Curtin Institute for Radio Astronomy (AU) at Curtin University and Deputy Executive Director at the International Center for Radio Astronomy Research (AU), a joint venture between Curtin University and the University of Western Australia (AU). And his team has found some pretty cool stuff in that static.

Turning the cosmic dial

Using the Murchison Widefield Array (MWA) telescope, a cutting-edge radio astronomy tech, Steven’s team has discovered a pulsar—a dense and rapidly spinning neutron star that pulses radio waves out into the universe.

While this is the first pulsar detected by the MWA, which is situated in Western Australia’s remote Mid-West region, it’s sure to not be the last. Indeed, this find shows how many of today’s great discoveries aren’t made by traveling to new worlds but by just listening to what’s already around us.

As Steven explains, “Each MWA antenna receives radio waves from all parts of the sky—all objects simultaneously, 24/7.

Yet you may be wondering, if your car radio can pick up radio waves from the universe, what makes the MWA so cutting edge?

Chunky data

Tuning in to Cosmic FM is only the first step. The hard part is crunching the numbers.

One of 256 tiles of the SKA Murchison Widefield Array (AU) (MWA) radio telescope. Credit: Pete Wheeler, ICRAR

“Once the MWA collects data, you need to process those data in different ways to extract different bits of information about different objects,” says Steven.

“We can turn the radio waves into an enormously rich dataset, and you can process those data in lots of different ways to learn different things … as long as you can afford the computing power.”

Indeed, if there is something limiting radio astronomers, it’s not their ability to pick up information. It’s the ability of computers to actually process the huge amounts of data.

So far, the MWA has collected about 40 petabytes of data—that’s equivalent to 40 million gigabytes. And if you thought that was big, say hello to the Square Kilometer Array (SKA) …

SKA-Square Kilometer Array

Hip to be square

One of the largest scientific endeavors in history, the SKA is a telescope with a lens of—you guessed it—a square kilometer. Although, importantly, it’s not one lens. It’s thousands of tiny lenses scattered across the world, from high-frequency dishes in South Africa to smaller low-frequency antennas in WA.

SKA- South Africa

SKA SARAO Meerkat telescope , 90 km outside the small Northern Cape town of Carnarvon, SA.
(SA)

“The MWA is comprised of 4000 individual antennas in WA, whereas the SKA will be comprised of more than 130,000 individual antennas in WA spread out over 120km.”

SKA Square Kilometre Array low frequency at Murchison Widefield Array, Boolardy station in outback Western Australia on the traditional lands of the Wajarri peoples

“The SKA will be much more sensitive than the MWA and will be able to make images in much finer detail.”

“MWA is 1% of what the SKA will be.”

The final frontier

That’s going to be a lot of data to crunch, but Steven is looking forward to using this incredible tool to ‘explore’ the last unexplored epoch in the universe’s evolution: its first billion years.

“Within that first billion years, the first generation of stars and galaxies formed, setting the scene for the evolution of the universe.”

Unlocking the mysteries of the first billion years of the universe? Let’s see your 2002 Honda Civic do that!

So next time you’re driving down the freeway and can’t quite tune in to the cricket, just sit and enjoy the static for a moment. You’re listening to the biggest radio show in the universe, and it’s all about how we got here.

See the full article here .

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Curtin University (AU) (formerly known as Curtin University of Technology and Western Australian Institute of Technology) is an Australian public research university based in Bentley and Perth, Western Australia. The university is named after the 14th Prime Minister of Australia, John Curtin, and is the largest university in Western Australia, with over 58,000 students (as of 2016).

Curtin would like to pay respect to the indigenous members of our community by acknowledging the traditional owners of the land on which the Perth campus is located, the Wadjuk people of the Nyungar Nation; and on our Kalgoorlie campus, the Wongutha people of the North-Eastern Goldfields.

Curtin was conferred university status after legislation was passed by the Parliament of Western Australia in 1986. Since then, the university has been expanding its presence and has campuses in Singapore, Malaysia, Dubai and Mauritius. It has ties with 90 exchange universities in 20 countries. The University comprises five main faculties with over 95 specialists centres. The University formerly had a Sydney campus between 2005 & 2016. On 17 September 2015, Curtin University Council made a decision to close its Sydney campus by early 2017.

Curtin University is a member of Australian Technology Network (ATN), and is active in research in a range of academic and practical fields, including Resources and Energy (e.g., petroleum gas), Information and Communication, Health, Ageing and Well-being (Public Health), Communities and Changing Environments, Growth and Prosperity and Creative Writing.

It is the only Western Australian university to produce a PhD recipient of the AINSE gold medal, which is the highest recognition for PhD-level research excellence in Australia and New Zealand.

Curtin has become active in research and partnerships overseas, particularly in mainland China. It is involved in a number of business, management, and research projects, particularly in supercomputing, where the university participates in a tri-continental array with nodes in Perth, Beijing, and Edinburgh. Western Australia has become an important exporter of minerals, petroleum and natural gas. The Chinese Premier Wen Jiabao visited the Woodside-funded hydrocarbon research facility during his visit to Australia in 2005.

From International Centre for Radio Astronomy Research – ICRAR (AU): “$64.4 million for WA to process signals from the dawn of time”

From International Centre for Radio Astronomy Research – ICRAR (AU)

April 16, 2021
Dr Karen Lee-Waddell
(AusSRC / ICRAR / CSIRO)
+61 413 547 256
Karen.Lee-Waddell@icrar.org

Professor Peter Quinn
(ICRAR / University of Western Australia)
+61 8 466 710 590
Peter.Quinn@icrar.org

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

The federal government will invest AU$64.4 million to establish a centre in Perth to process and analyse data from the Square Kilometre Array (SKA) radio telescope.

SKA- Square Kilometer Array

A global collaboration of 16 countries, the SKA will be one of the world’s largest science facilities, exploring the entire history and evolution of the Universe, and uncovering advances in fundamental physics.

A 20-second exposure showing the Milky Way overhead the AAVS station. Credit: Michael Goh and ICRAR/Curtin University (AU).

Construction of the telescope is expected to begin at the end of this year. Initially, it will comprise 131,072 low-frequency Christmas tree-shaped antennas located in WA’s remote Murchison region and 197 mid-frequency dish-shaped antennas hosted in South Africa’s Karoo region.

SKA Square Kilometre Array -low frequency at Murchison Widefield Array, Boolardy station in outback Western Australia, at the Murchison Radio-astronomy Observatory (AU), on the traditional lands of the Wajarri peoples.

SKA SARAO – South African Radio Astronomy Observatory (SA) Mid Frequency Aperture Array Karoo, South Africa.

Around 7 terabits of data will travel from Australia’s SKA antennas to supercomputers in Perth every second.

The Australian Square Kilometre Array Regional Centre (AusSRC), a collaboration between ICRAR, Australia’s national science agency CSIRO-Commonwealth Scientific and Industrial Research Organisation (AU) and the Pawsey Supercomputing Centre (AU), is part of an international network of SKA Regional Centres that will support the global flow of data and processing needed for the telescope.

Pawsey Supercomputing Centre, Perth, AU

Magnus Cray XC40 supercomputer

Galaxy Cray XC30 Series Supercomputer

Fujisto Raijin supercomputer

Fujitsu Raijin Supercomputer

Pausey HPE Cray EX supercomputer.

“When the telescope is switched on, it will open the floodgates to a massive amount of data, as signals from all over the Universe pour in—it’s an enormous and very exciting challenge for us,” said AusSRC director, Dr Karen Lee-Waddell.

“The flow of data will be roughly 100,000 times faster than your average home broadband speed.

“Each year, we’ll store around 600 petabytes coming from the SKA telescopes for astronomers and astrophysicists from all over the world to access and analyse,” she said.

“To put that into perspective, Netflix’s collection of movies is currently around 15,000 titles, and we’ll be storing 10,000 times more data than this every year.”

Composite image of the SKA-Low telescope in Western Australia. The image blends a real photo (on the left) of the SKA-Low prototype station AAVS2.0 which is already on site, with an artists impression of the future SKA-Low stations as they will look when constructed. These dipole antennas, which will number in their hundreds of thousands, will survey the radio sky in frequencies as low at 50Mhz. Credit ICRAR and SKAO.

The federal funding to establish a facility in Perth is part of AU$387 million announced for the SKA project by Prime Minister Scott Morrison during a trip to Western Australia this week.

In 2015, the Australian Government provided AU$293.7 million to support the SKA under the National Innovation and Science Agenda (NISA), in recognition that science, research and innovation projects can drive long-term economic prosperity, jobs and growth.

Since 2009, the WA Government has provided AU$71 million in funding for the International Centre for Radio Astronomy Research (ICRAR), attracting the SKA to Western Australia and maximising benefits for the State through research, job creation, diversification of the economy and innovation.

Executive director of ICRAR, Professor Peter Quinn, said, “This is an astronomical day for science in WA and Australia.”

“After almost thirty years of design, development and preparation, this investment by the Commonwealth Government sends a message to the international community that Australia is fully ready to start building the SKA,” he said.

“This project will not only help us better understand the Universe we live in, it will also provide STEM careers for the next generation and new technologies that benefit the everyday lives of millions of people around the world.

“All Australians should be proud that this country is going to host the SKA, one of the biggest science projects in human history.”

See the full article here .

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ICRAR(AU) 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(AU) has strong support from the government of Australia and is working closely with industry and the astronomy community, including CSIRO(AU) and the Australian Telescope National Facility, <a
ICRAR is:

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

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

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

A Small part of the Murchison Widefield Array(AU)

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.

From The Conversation: “A 4G network on the Moon is bad news for radio astronomy”

From The Conversation

October 23, 2020
Emma Alexander

A partial lunar eclipse above the Jodrell Bank Observatory in Cheshire in 2019. Credit: Peter Byrne/PA Archive/PA Images.

As you drive down the road leading to Jodrell Bank Observatory, a sign asks visitors to turn off their mobile phones, stating that the Lovell telescope is so powerful it could detect a phone signal on Mars.

Radio telescopes are designed to be incredibly sensitive. To quote the legendary astronomer Carl Sagan, “The total amount of energy from outside the solar system ever received by all the radio telescopes on the planet Earth is less than the energy of a single snowflake striking the ground.”

The total energy now is probably a few snowflakes’ worth, but nevertheless it is still true that astronomical radio signals are typically magnitudes smaller than artificial ones. If Jodrell Bank could pick up interference from a phone signal on Mars, how would it fare with an entire 4G network on the Moon?

That is the issue that is worrying astronomers like me, now that Nokia of America has been awarded US$14.1m (£10.8m) for the development of the first ever cellular network on the Moon. The LTE/4G network will aim to facilitate long term lunar habitability, providing communications for key aspects such as lunar rovers and navigation.

Network interference

Radio frequency interference (RFI) is the long-term nemesis of radio astronomers. Jodrell Bank – the earliest radio astronomy observatory in the world still in existence – was created because of RFI. Sir Bernard Lovell, one of the pioneers of radio astronomy, found his work at Manchester hampered by RFI from passing trams in the city, and he persuaded the university’s botany department to let him move to their fields in Cheshire for two weeks (he never left).

Sir Bernard Lovell, Director of Jodrell Bank Radio Astronomy Station, Cheshire, in 1964. Credit: PA/PA Archive/PA Images.

Since then, radio telescopes have been built more and more remotely in an attempt to avoid RFI, with the upcoming Square Kilometre Array (SKA) telescope being built across remote areas of South Africa and Australia.

SKA- Square Kilometer Array

SKA- South Africa.

SKA Meerkat South Africa

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

This helps to cut out many common sources for RFI, including mobile phones and microwave ovens. However, ground-based radio telescopes cannot completely avoid space-based sources of RFI such as satellites – or a future lunar telecommunications network.

RFI can be mitigated at the source with appropriate shielding and precision in the emission of signals. Astronomers are constantly developing strategies to cut RFI from their data. But this increasingly relies on the goodwill of private companies to ensure that at least some radio frequencies are protected for astronomy.

A long-term dream of many radio astronomers would be to have a radio telescope on the far side of the Moon. In addition to being shielded from Earth-based signals, it would also be able to observe at the lowest radio frequencies, which on Earth are particularly affected by a part of the atmosphere called the ionosphere. Observing at low radio frequencies can help answer fundamental questions about the universe, such as what it was like in the first few moments after the big bang.

The science case has already been recognised with the Netherlands-China Low Frequency Explorer, a telescope repurposed from the Queqiao relay satellite sent to the Moon in the Chang’e 4 mission.

Netherlands-China Low Frequency Explorer

A render of the Chang’e-4 rover on the lunar surface, released Aug. 15, 2018 (Credit: CASC)

Nasa has also funded a project on the feasibility of turning a lunar crater into a radio telescope with a lining of wire mesh.

It’s not just 4G

Despite its interest in these radio projects, NASA also has its eye commercial partnerships. Nokia is just one of 14 American companies NASA is working with in a new set of partnerships, worth more than US$370m, for the development of its Artemis programme, which aims to return astronauts to the Moon by 2024.

NASA ARTEMIS spacecraft depiction.

The involvement of private companies in space technology is not new. And the rights and wrongs have long been debated. Drawing possibly the most attention has been SpaceX’s Starlink satellites, which caused a stir among astronomers after their first major launch in 2019.

Images quickly began to emerge with trails of Starlink satellites cutting across them – often obscuring or outshining the original astronomical targets.

An artist’s impression of the planned SKA-mid dishes in Africa.

Astronomers have had to deal with satellites for a long time, but Starlink’s numbers and brightness are unprecedented and and their orbits are difficult to predict. These concerns apply to anyone doing ground-based astronomy, whether they use an optical or a radio telescope.

A recent analysis of satellite impact on radio astronomy was released by the SKA Organisation, which is developing the next generation of radio telescope technology for the Square Kilometre Array. It calculated that the SKA telescopes would be 70% less sensitive in the radio band that Starlink uses for communications, assuming an eventual number of 6,400 Starlink satellites.

As space becomes more and more commercialised, the sky is filling with an increasing volume of technology. That is why it has never been more important to have regulations protecting astronomy. To help ensure that as we take further steps into space, we’ll still be able to gaze at it from our home on Earth.

See the full article here .

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Please help promote STEM in your local schools.

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The Conversation launched as a pilot project in October 2014. It is an independent source of news and views from the academic and research community, delivered direct to the public.
Our team of professional editors work with university and research institute experts to unlock their knowledge for use by the wider public.
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