Tagged: Radio Astronomy Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 1:22 pm on May 10, 2021 Permalink | Reply
    Tags: "High-mass stars are formed not from dust disk but from debris", , , , , , , , Radio Astronomy   

    From Leiden University [Universiteit Leiden] (NL) : “High-mass stars are formed not from dust disk but from debris” 

    From Leiden University [Universiteit Leiden] (NL)

    03 May 2021

    Credit: CC0 Public Domain

    A Dutch-led team of astronomers has discovered that high-mass stars are formed differently from their smaller siblings. Whereas small stars are often surrounded by an orderly disk of dust and matter, the supply of matter to large stars is a chaotic mess. The researchers used the Atacama Large Millimeter/submillimeter Array (ALMA) telescope for their observations, and recently published their findings in The Astrophysical Journal.

    It is well known how small, young stars are created. They accrete matter from a disk of gas and dust in a relatively orderly fashion. Astronomers have already seen many of these disks of dust around young, low-mass stars but never around young, high-mass stars. This raised the question of whether large stars come into existence in the same way as small ones.

    Large stars are formed in a different way

    “Our findings now provide convincing evidence to show that the answer is ‘No'”, according to Ciriaco Goddi, affiliated with the ALMA expertise centre Allegro at Leiden University and with Radboud University [Radboud Universiteit](NL) in Nijmegen.

    Goddi led a team that studied three young, high-mass stars in star-forming region W51, roughly 17,000 light years from Earth. The researchers were looking in particular for large, stable disks expelling jets of matter perpendicular to the surface of the disk. Such disks should be visible with the high resolution ALMA telescopes.

    Not stable disks but chaos

    Goddi: “But instead of stable disks, we discovered that the accretion zone of young, high-mass stars looks like a chaotic mess.”

    The observation showed strands of gas coming at the young, high-mass stars from all directions. In addition, the researchers saw jets which indicate that there may be small disks, invisible to the telescope. Also, it would appear that some hundred years ago the disk around one of three stars studied rotated. In short: chaos.

    Matter from multiple directions

    The researchers concluded that these young, high-mass stars, in their early years at least, are formed by matter coming from multiple directions and at an irregular speed. This is different for small stars, where there is a stable influx of matter. The astronomers suspect that that multiple supply of matter is probably the reason that no large, stable disks can be created.

    “Such an unstructured influx model had previously been proposed, on the basis of computer simulations. We now have the first observational evidence to support the model”, says Goddi.

    See the full article here.


    Please help promote STEM in your local schools.

    Stem Education Coalition

    Universiteit Leiden Heijmans onderhoudt

    Leiden University [Universiteit Leiden] (NL) is a public research university in Leiden, Netherlands. Founded in 1575 by William, Prince of Orange as a reward to the town of Leiden for its defense against Spanish attacks during the Eighty Years’ War, it is the oldest institution of higher education in the Netherlands.

    Known for its historic foundations and emphasis on the social sciences, the university came into particular prominence during the Dutch Golden Age, when scholars from around Europe were attracted to the Dutch Republic due to its climate of intellectual tolerance and Leiden’s international reputation. During this time, Leiden became the home to individuals such as René Descartes, Rembrandt, Christiaan Huygens, Hugo Grotius, Baruch Spinoza and Baron d’Holbach.

    The university has seven academic faculties and over fifty subject departments while housing more than 40 national and international research institutes. Its historical primary campus consists of buildings scattered across the college town of Leiden, while a second campus located in The Hague houses a liberal arts college and several of its faculties. It is a member of the Coimbra Group, the Europaeum, and a founding member of the League of European Research Universities.

    Leiden University consistently ranks among the top 100 universities in the world by major ranking tables. It was placed top 50 worldwide in thirteen fields of study in the 2020 QS World University Rankings: classics & ancient history, politics, archaeology, anthropology, history, pharmacology, law, public policy, public administration, religious studies, arts & humanities, linguistics, modern languages and sociology.

    The school has produced twenty-one Spinoza Prize Laureates and sixteen Nobel Laureates, including Enrico Fermi and Albert Einstein. It is closely associated with the Dutch Royal Family, with Queen Juliana, Queen Beatrix and King Willem-Alexander being alumni. Ten prime ministers of the Netherlands were also Leiden University alumni. Internationally, it is associated with nine foreign leaders, among them John Quincy Adams (the 6th President of the United States), two NATO Secretaries General, a President of the International Court of Justice, and a Prime Minister of the United Kingdom.

    In 1575, the emerging Dutch Republic did not have any universities in its northern heartland. The only other university in the Habsburg Netherlands was the University of Leuven [Universiteit Leuven](BE) in southern Leuven, firmly under Spanish control. The scientific renaissance had begun to highlight the importance of academic study, so Prince William founded the first Dutch university in Leiden, to give the Northern Netherlands an institution that could educate its citizens for religious purposes, but also to give the country and its government educated men in other fields. It is said the choice fell on Leiden as a reward for the heroic defence of Leiden against Spanish attacks in the previous year. Ironically, the name of Philip II of Spain, William’s adversary, appears on the official foundation certificate, as he was still the de jure count of Holland. Philip II replied by forbidding any subject to study in Leiden. Originally located in the convent of St Barbara, the university moved to the Faliede Bagijn Church in 1577 (now the location of the University museum) and in 1581 to the convent of the White Nuns, a site which it still occupies, though the original building was destroyed by fire in 1616.

    The presence within half a century of the date of its foundation of such scholars as Justus Lipsius; Joseph Scaliger; Franciscus Gomarus; Hugo Grotius; Jacobus Arminius; Daniel Heinsius; and Gerhard Johann Vossius rapidly made Leiden university into a highly regarded institution that attracted students from across Europe in the 17th century. Renowned philosopher Baruch Spinoza was based close to Leiden during this period and interacted with numerous scholars at the university. The learning and reputation of Jacobus Gronovius; Herman Boerhaave; Tiberius Hemsterhuis; and David Ruhnken, among others, enabled Leiden to maintain its reputation for excellence down to the end of the 18th century.

    At the end of the nineteenth century, Leiden University again became one of Europe’s leading universities. In 1896 the Zeeman effect was discovered there by Pieter Zeeman and shortly afterwards given a classical explanation by Hendrik Antoon Lorentz. At the world’s first university low-temperature laboratory, professor Heike Kamerlingh Onnes achieved temperatures of only one degree above absolute zero of −273 degrees Celsius. In 1908 he was also the first to succeed in liquifying helium and can be credited with the discovery of the superconductivity in metals.

    The University Library, which has more than 5.2 million books and fifty thousand journals, also has a number of internationally renowned special collections of western and oriental manuscripts, printed books, archives, prints, drawings, photographs, maps, and atlases. It houses the largest collections worldwide on Indonesia and the Caribbean. The research activities of the Scaliger Institute focus on these special collections and concentrate particularly on the various aspects of the transmission of knowledge and ideas through texts and images from antiquity to the present day.

    In 2005 the manuscript of Einstein on the quantum theory of the monatomic ideal gas (the Einstein-Bose condensation) was discovered in one of Leiden’s libraries.

    The portraits of many famous professors since the earliest days hang in the university aula, one of the most memorable places, as Niebuhr called it, in the history of science.

    In 2012 Leiden entered into a strategic alliance with Delft University of Technology [Technische Universiteit Delft](NL) and Erasmus University Rotterdam [Erasmus Universiteit Rotterdam](NL)in order for the universities to increase the quality of their research and teaching. The university is also the unofficial home of the Bilderberg Group, a meeting of high-level political and economic figures from North America and Europe.

    The university has no central campus; its buildings are spread over the city. Some buildings, like the Gravensteen, are very old, while buildings like Lipsius and Gorlaeus are much more modern.

    Among the institutions affiliated with the university are The KITLV or Royal Netherlands Institute of Southeast Asian and Caribbean Studies [Koninklijk Instituut voor Taal-, Land- en Volkenkunde] (NL) (founded in 1851); the observatory 1633; the natural history museum; with a very complete anatomical cabinet; the Rijksmuseum van Oudheden (National Museum of Antiquities) with specially valuable Egyptian and Indian departments; a museum of Dutch antiquities from the earliest times; and three ethnographical museums, of which the nucleus was Philipp Franz von Siebold’s Japanese collections. The anatomical and pathological laboratories of the university are modern, and the museums of geology and mineralogy have been restored.

    The Hortus Botanicus (botanical garden) is the oldest botanical garden in the Netherlands, and one of the oldest in the world. Plants from all over the world have been carefully cultivated here by experts for more than four centuries. The Clusius garden (a reconstruction), the 18th century Orangery with its monumental tub plants, the rare collection of historical trees hundreds of years old, the Japanese Siebold Memorial Museum symbolising the historical link between East and West, the tropical greenhouses with their world class plant collections, and the central square and Conservatory exhibiting exotic plants from South Africa and southern Europe.

  • richardmitnick 11:08 am on May 6, 2021 Permalink | Reply
    Tags: "FAST detects 3D spin-velocity alignment in a pulsar", , , , , Radio Astronomy   

    From Chinese Academy of Sciences [中国科学院] (CN): “FAST detects 3D spin-velocity alignment in a pulsar” 

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

    Illustration of supernova remnant S147 and pulsar J0538+2817. National Astronomical Observatories Xinglong Observatory [兴隆观测站] (CN).

    Pulsars – another name for fast-spinning neutron stars – originate from the imploded cores of massive dying stars through supernova explosion.

    Dame Susan Jocelyn Bell Burnell, discovered pulsars with radio astronomy. Jocelyn Bell at the Mullard Radio Astronomy Observatory, University of Cambridge(UK), taken for the Daily Herald newspaper in 1968. Denied the Nobel.

    Now, more than 50 years after the discovery of pulsars and confirmation of their association with supernova explosions, the origin of the initial spin and velocity of pulsars is finally beginning to be understood.

    Based on observations from the Five-hundred-meter Aperture Spherical radio Telescope (FAST), Dr. YAO Jumei, member of a team led by Dr. LI Di from National Astronomical Observatories Xinglong Observatory [兴隆观测站] (NAOC) (CN) of Chinese Academy of Sciences [中国科学院](CN) , found the first evidence for three-dimensional (3D) spin-velocity alignment in pulsars.

    The study was published in Nature Astronomy on May 6. It also marks the beginning of in-depth pulsar research with FAST.

    For decades, scientists have found observational evidence for spin-velocity alignment in young pulsars. The relationship thus revealed between pulsars’ spin axis and spatial velocity vectors, however, has largely been restricted to a 2D sky plane perpendicular to the line of sight, due to the hardship in constraining radial velocity.

    Focusing on PSR J0538+2817 in the supernova remnant (SNR) S147 and through the scintillation technique, Dr. YAO obtained its radial location with respect to the SNR boundary and its radial velocity for the first time. “Then we got the 3D velocity by combining the transverse velocity measured by Very Long Baseline Interferometers,” said Dr. YAO. The polarization analysis resulted in the direction of the 3D spin axis. The best fit angle between these two vectors was found to be about 10 degrees, which is the first such measurement in 3D.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Chinese Academy of Sciences [中国科学院] (CN) is the linchpin of China’s drive to explore and harness high technology and the natural sciences for the benefit of China and the world. Comprising a comprehensive research and development network, a merit-based learned society and a system of higher education, CAS brings together scientists and engineers from China and around the world to address both theoretical and applied problems using world-class scientific and management approaches.

    Since its founding, CAS has fulfilled multiple roles — as a national team and a locomotive driving national technological innovation, a pioneer in supporting nationwide S&T development, a think tank delivering S&T advice and a community for training young S&T talent.

    Now, as it responds to a nationwide call to put innovation at the heart of China’s development, CAS has further defined its development strategy by emphasizing greater reliance on democratic management, openness and talent in the promotion of innovative research. With the adoption of its Innovation 2020 programme in 2011, the academy has committed to delivering breakthrough science and technology, higher caliber talent and superior scientific advice. As part of the programme, CAS has also requested that each of its institutes define its “strategic niche” — based on an overall analysis of the scientific progress and trends in their own fields both in China and abroad — in order to deploy resources more efficiently and innovate more collectively.

    As it builds on its proud record, CAS aims for a bright future as one of the world’s top S&T research and development organizations.

  • richardmitnick 4:17 pm on May 5, 2021 Permalink | Reply
    Tags: "Lunar Crater Radio Telescope: Illuminating the Cosmic Dark Ages", , DuAxel rovers would build the telescope., Even China's even FAST is not sensitive to radio wavelengths longer than about 14 feet (4.3 meters)., Measure the long-wavelength radio waves generated by the Cosmic Dark Ages., , On the Moon’s far side there’s no atmosphere to reflect signals., Radio Astronomy, Radio telescopes on Earth can’t probe this mysterious period because the long-wavelength radio waves from that time are reflected by a layer of ions and electrons at the top of our atmosphere., The LCRT would be made of thin wire mesh in the center of the crater., The LCRT would need to be huge., There was ample hydrogen during the universe’s Dark Ages – hydrogen that would eventually serve as the raw material for the first stars., This class of radio telescope uses thousands of reflecting panels suspended inside the depression to make the entire dish’s surface reflective to radio waves.   

    From NASA JPL-Caltech : “Lunar Crater Radio Telescope: Illuminating the Cosmic Dark Ages” 

    NASA JPL Banner

    From NASA JPL-Caltech

    May 05, 2021

    Ian J. O’Neill
    Jet Propulsion Laboratory, Pasadena, Calif.

    Clare Skelly
    NASA Headquarters, Washington

    Illustration of lunar crater radio telescope. Vladimir Vustyansky.

    Wire mesh inside crater. Vladimir Vustyansky.

    Lunar surface has plenty of craters.Vladimir Vustyansky.

    The early-stage NASA concept could see robots hang wire mesh in a crater on the Moon’s far side, creating a radio telescope to help probe the dawn of the universe.

    After years of development, the Lunar Crater Radio Telescope (LCRT) project has been awarded $500,000 to support additional work as it enters Phase II of NASA’s Innovative Advanced Concepts (NIAC) program. While not yet a NASA mission, the LCRT describes a mission concept that could transform humanity’s view of the cosmos.

    The LCRT’s primary objective would be to measure the long-wavelength radio waves generated by the cosmic Dark Ages – a period that lasted for a few hundred million years after the Big Bang, but before the first stars blinked into existence. Cosmologists know little about this period, but came the answers to some of science’s biggest mysteries may be locked in the long-wavelength radio emissions generated by the gas that would have filled the universe during that time.

    “While there were no stars, there was ample hydrogen during the universe’s Dark Ages – hydrogen that would eventually serve as the raw material for the first stars,” said Joseph Lazio, radio astronomer at NASA’s Jet Propulsion Laboratory in Southern California and a member of the LCRT team. “With a sufficiently large radio telescope off Earth, we could track the processes that would lead to the formation of the first stars, maybe even find clues to the nature of dark matter.”

    Radio telescopes on Earth can’t probe this mysterious period because the long-wavelength radio waves from that time are reflected by a layer of ions and electrons at the top of our atmosphere, a region called the ionosphere. Random radio emissions from our noisy civilization can interfere with radio astronomy as well, drowning out the faintest signals.

    But on the Moon’s far side there’s no atmosphere to reflect these signals, and the Moon itself would block Earth’s radio chatter. The lunar far side could be prime real estate to carry out unprecedented studies of the early universe.

    “Radio telescopes on Earth cannot see cosmic radio waves at about 33 feet [10 meters] or longer because of our ionosphere, so there’s a whole region of the universe that we simply cannot see,” said Saptarshi Bandyopadhyay, a robotics technologist at JPL and the lead researcher on the LCRT project. “But previous ideas of building a radio antenna on the Moon have been very resource intensive and complicated, so we were compelled to come up with something different.”

    Building Telescopes With Robots

    To be sensitive to long radio wavelengths, the LCRT would need to be huge. The idea is to create an antenna over half-a-mile (1 kilometer) wide in a crater over 2 miles (3 kilometers) wide. The biggest single-dish radio telescopes on Earth – like the 1,600-foot (500-meter) Five-hundred-meter Aperture Spherical Telescope (FAST) in China and the now-inoperative 1,000-foot-wide (305-meter-wide) Arecibo Observatory in Puerto Rico – were built inside natural bowl-like depressions in the landscape to provide a support structure.

    This class of radio telescope uses thousands of reflecting panels suspended inside the depression to make the entire dish’s surface reflective to radio waves. The receiver then hangs via a system of cables at a focal point over the dish, anchored by towers at the dish’s perimeter, to measure the radio waves bouncing off the curved surface below. But despite its size and complexity, even FAST is not sensitive to radio wavelengths longer than about 14 feet (4.3 meters).

    With his team of engineers, roboticists, and scientists at JPL, Bandyopadhyay condensed this class of radio telescope down to its most basic form. Their concept eliminates the need to transport prohibitively heavy material to the Moon and utilizes robots to automate the construction process. Instead of using thousands of reflective panels to focus incoming radio waves, the LCRT would be made of thin wire mesh in the center of the crater. One spacecraft would deliver the mesh, and a separate lander would deposit DuAxel rovers to build the dish over several days or weeks.

    DuAxel, a robotic concept being developed at JPL, is composed of two single-axle rovers (called Axel) that can undock from each other but stay connected via a tether. One half would act as an anchor at the rim of the crater as the other rappels down to do the building.

    “DuAxel solves many of the problems associated with suspending such a large antenna inside a lunar crater,” said Patrick Mcgarey, also a robotics technologist at JPL and a team member of the LCRT and DuAxel projects. “Individual Axel rovers can drive into the crater while tethered, connect to the wires, apply tension, and lift the wires to suspend the antenna.”

    Identifying Challenges

    For the team to take the project to the next level, they’ll use NIAC Phase II funding to refine the capabilities of the telescope and the various mission approaches while identifying the challenges along the way.

    One of the team’s biggest challenges during this phase is the design of the wire mesh. To maintain its parabolic shape and precise spacing between the wires, the mesh must be both strong and flexible, yet lightweight enough to be transported. The mesh must also be able to withstand the wild temperature changes on the Moon’s surface – from as low as minus 280 degrees Fahrenheit (minus 173 degrees Celsius) to as high as 260 degrees Fahrenheit (127 degrees Celsius) – without warping or failing.

    Another challenge is to identify whether the DuAxel rovers should be fully automated or involve a human operator in the decision-making process. Might the construction DuAxels also be complemented by other construction techniques? Firing harpoons into the lunar surface, for example, may better anchor the LCRT’s mesh, requiring fewer robots.

    Also, while the lunar far side is “radio quiet” for now, that may change in the future. China’s space agency currently has a mission exploring the lunar far side, after all, and further development of the lunar surface could impact possible radio astronomy projects.

    For the next two years, the LCRT team will work to identify other challenges and questions as well. Should they be successful, they may be selected for further development, an iterative process that inspires Bandyopadhyay.

    “The development of this concept could produce some significant breakthroughs along the way, particularly for deployment technologies and the use of robots to build gigantic structures off Earth,” he said. “I’m proud to be working with this diverse team of experts who inspire the world to think of big ideas that can make groundbreaking discoveries about the universe we live in.”

    NIAC is funded by NASA’s Space Technology Mission Directorate, which is responsible for developing the new cross-cutting technologies and capabilities needed by the agency.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    NASA JPL Campus

    Jet Propulsion Laboratory (JPL)) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge, on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

    Caltech Logo

  • richardmitnick 2:25 pm on May 5, 2021 Permalink | Reply
    Tags: "A new window to see hidden side of magnetized universe", , , , , , MRC 0600-399 is the core of a sub-cluster penetrating the main cluster of galaxies., Radio Astronomy   

    From National Institute of Natural Sciences (自然科学研究機] (JP): “A new window to see hidden side of magnetized universe” 

    From National Institute of Natural Sciences (自然科学研究機構] (JP)

    The bent jet structures emitted from MRC 0600-399 as observed by the MeerKAT radio telescope (left) are well reproduced by the simulation conducted on ATERUI II (right). The nearby galaxy B visible in the left part of the MeerKAT image is not affecting the jet and has been excluded in the simulation. Credit: Chibueze, Sakemi, Ohmura et al. (MeerKAT image); Takumi Ohmura, Mami Machida, Hirotaka Nakayama, 4D2U Project, National Astronomy Observatory of Japan (JP) (ATERUI II image)

    New observations and simulations show that jets of high-energy particles emitted from the central massive black hole in the brightest galaxy in galaxy clusters can be used to map the structure of invisible inter-cluster magnetic fields. These findings provide astronomers with a new tool for investigating previously unexplored aspects of clusters of galaxies.

    As clusters of galaxies grow through collisions with surrounding matter, they create bow shocks and wakes in their dilute plasma. The plasma motion induced by these activities can drape intra-cluster magnetic layers, forming virtual walls of magnetic force. These magnetic layers, however, can only be observed indirectly when something interacts with them. Because it is simply difficult to identify such interactions, the nature of intra-cluster magnetic fields remains poorly understood. A new approach to map/characterize magnetic layers is highly desired.

    An international team of astronomers including Haruka Sakemi, a graduate student at Kyushu University [九州大学](JP) (now a research fellow at the National Astronomical Observatory of Japan—NAOJ), used the MeerKAT radio telescope located in the Northern Karoo desert of South Africa to observe a bright galaxy in the merging galaxy cluster Abell 3376 known as MRC 0600-399.

    Located more than 600 million light-years away in the direction of the constellation Columba, MRC 0600-399 is known to have unusual jet structures bent to 90-degree angles. Previous X-ray observations revealed that MRC 0600-399 is the core of a sub-cluster penetrating the main cluster of galaxies, indicating the presence of strong magnetic layers at the boundary between the main and sub-clusters. These features make MRC 0600-399 an ideal laboratory to investigate interactions between jets and strong magnetic layers.

    The MeerKAT observations revealed unprecedented details of the jets, most strikingly, faint ‘double-scythe’ structure extending in the opposite direction from the bend points and creating a “T” shape. These new details show that, like a stream of water hitting a pane of glass, this is a very chaotic collision. Dedicated computer simulations are required to explain the observed jet morphology and possible magnetic field configurations.

    Takumi Ohmura, a graduate student at Kyushu University (now a research fellow at the University of Tokyo[(東京大] (JP)‘s Institute for Cosmic-Ray Research—ICRR), from the team performed simulations on NAOJ’s supercomputer ATERUI II, the most powerful computer in the world dedicated to astronomical calculations. The simulations assumed an arch-like strong magnetic field, neglecting messy details like turbulence and the motion of the galaxy. This simple model provides a good match to the observations, indicating that the magnetic pattern used in the simulation reflects the actual magnetic field intensity and structure around MRC 0600-399. More importantly, it demonstrates that the simulations can successfully represent the underlying physics so that they can be used on other objects to characterize more complex magnetic field structures in clusters of galaxies. This provides astronomers with a new way to understand the magnetized Universe and a tool to analyze the higher-quality data from future radio observatories like the SKA (the Square Kilometre Array).

    These results appeared in Nature on May 6, 2021.

    See the full article here.


    Please help promote STEM in your local schools.

    Stem Education Coalition

    The National Institute of Natural Sciences (自然科学研究機構; Shizenkagaku kenkyuukikou) (NINS) is an inter-university research institute corporation consisting of five member institutes: the National Astronomical Observatory (NAOJ), the National Institute for fusion Science (NIFS), the National Institute for Basic Biology (NIBB), the National Institute for Physiological Sciences (NIPS), and the Institutes for Molecular Sciences (IMS). NINS was established in April 2004 to bring about further development of the natural sciences in Japan.

    The five institutes established under NINS are Japan’s main centers of academic research in their respective fields. These institutes cooperate actively as a base for interdisciplinary research in natural science with universities, university-affiliated research institutes, and inter-university research institutes to promote the formation of new research communities.

    NINS established the Research Cooperation and Liaison Committee under the authority of the President, to discuss and plan matters of research cooperation. It has also established the Research Cooperation and Liaison Office, which is in charge of implementing plans made by the Research Cooperation and Liaison Committee. The Research Cooperation and Liaison Office has set “Imaging science” and “Hierarchy and Holism in Natural Science” as themes for cooperation across fields, and is promoting symposiums and other projects under these themes.

  • richardmitnick 5:41 pm on May 3, 2021 Permalink | Reply
    Tags: "The patchy environment of a rare cosmic explosion revealed", , AT 2018cow, , , FBOT- Fast Blue Optical Transient, Radio Astronomy,   

    From Tata Institute of Fundamental Research (IN) : “The patchy environment of a rare cosmic explosion revealed” 

    Tata Institute of Fundamental Research IN

    From Tata Institute of Fundamental Research (IN)

    An Artists conception of FBOT. Credit: Bill Saxton, National Radio Astronomy Observatory (US)/Associated Universities Inc (US)/National Science Foundation (US).

    Scientists from the National Centre for radio Astrophysics of the Tata Institute of Fundamental Research (NCRA-TIFR) Pune used the upgraded Giant Metrewave Radio Telescope (uGMRT) to determine that AT 2018 cow, the first of a newly discovered class of cosmic explosions, has an extremely patchy environment.


    Upgraded Giant Metrewave Radio Telescope, an array of thirty telecopes, located near Pune in India.

    Sources like AT 2018cow release an enormous amount of energy, nonetheless fade extremely rapidly. This along with their extremely blue color has led to them being called FBOTs for Fast Blue Optical Transient. This is the first observational evidence of inhomogeneous emission from an FBOT. The origins of FBOTs are still under debate, but proposed models include explosion of a massive star, collision of an accreting neutron star and a star, merger of two white dwarfs, etc.

    The FBOTs are difficult to find since they appear and vanish in the sky very quickly. However, several of them have been discovered in the past few years via the recent advent of surveys that scan the sky almost on daily basis. FBOTs that also emit in the radio are doubly rare, but are particularly interesting because radio observations help one to determine the properties of the environments of these explosions and their progenitors.

    The FBOT AT2018cow was discovered on 16 June 2018. At a distance of about 215 million light-years, the cow showed luminosities much greater than that of normal supernovae. Prof. Poonam Chandra (NCRA-TIFR) and Dr. A. J. Nayana (a former Ph.D. student of Prof. Poonam Chandra) carried out radio observations of AT 2018cow with the uGMRT to determine the properties of its extended environment and emission region. “Our study has tremendously benefited by the unique low-frequency capabilities of the uGMRT. The uGMRT observations of the “cow” played an unique role in finding the non-uniform density around this explosion”, says Nayana. She added, “Our work provides the first observational evidence of inhomogeneous emission from an FBOT. The density of the material around this explosion falls drastically around 0.1 light-year from the transient. This indicates that the progenitor star of AT2018cow was shedding mass much faster towards its end of life.”

    The green and red solid/dotted lines denote different theoretical models. The turn over point of this light curve enabled the determination of material velocity from the explosion, magnetic field strength, and environmental density at different distances from the explosion centre. Credit: A. J. Nayana and Poonam Chandra.

    AT 2018cow is also unusual in that it has been observable in the radio for a very long time. The longer one can observe the post explosion emission, the more distance the material that was ejected during the explosion has traveled. This allows one to study the large scale environment of the source. Dr. A. J. Nayana and Prof. Poonam Chandra have been observing the cow for ~ 2 years with the uGMRT to understand its properties. “This is the first FBOT seen for this long at low radio frequencies and the uGMRT data gave crucial information about the environment of this transient.”, Nayana said. Poonam Chandra explains, “This is the beauty of low-frequency radio observations. One gets to trace the footprints of the progenitor system much before it exploded. It is interesting that the material from the explosion is moving with speed greater than 20% speed of light even after ~257 days post-explosion, without any deceleration”.

    The image inside the box is the AT2018cow. Credit: A. J. Nayana and Poonam Chandra.

    While the origin of FBOTs is still under debate, detailed radio observations can give hints about various physical parameters of these events like the speed of the material that came out of this explosion, the magnetic field strength, the rate by which the progenitor system sheds its mass before the explosion, etc. The uGMRT observations of the “cow” suggest that the progenitor erupted its material ~100 times faster during the years close to its end-of-life compared to ~23 years before the explosion. Also, AT2018cow showed inhomogeneities in the radio-emitting region whereas the other two radio bright FBOTs did not show these properties, making the “cow” unique in the group. “Observations of more FBOTs with the uGMRT will give information about their environments and progenitors to develop a comprehensive picture of the properties of these intriguing transients.”, says Nayana.

    The GMRT is an array of thirty 45-m antennas spread over 25 sq-km area in Khodad village, Narayangaon, India, built and operated by NCRA-TIFR, Pune. Currently it is one of the most sensitive low frequency radio telescope in the world.

    The paper was published in the April 30, 2021 issue of The Astrophysical Journal Letters.

    See the full article here.


    Please help promote STEM in your local schools.

    Stem Education Coalition

    [caption id="attachment_119479" align="alignnone" width="632"] Tata Institute of Fundamental Research IN campus

    Tata Institute of Fundamental Research (IN)

    TIFR is a National Centre of the Government of India, under the umbrella of the Department of Atomic Energy, as well as a deemed University awarding degrees for master’s and doctoral programs. The Institute was founded in 1945 with support from the Sir Dorabji Tata Trust under the vision of Dr. Homi Bhabha. At TIFR, we carry out basic research in physics, chemistry, biology, mathematics, computer science and science education. Our main campus is located in Mumbai, with centres at Pune, Bengaluru and Hyderabad.

  • richardmitnick 12:58 pm on April 29, 2021 Permalink | Reply
    Tags: "Astronomers Detect Another Mysterious Ghostly Circle in Extragalactic Space", Almost bang in the center of the ORC the team found something: an elliptical radio galaxy named DES J010224.33-245039.5., , Australian Square Kilometre Array, , , Odd radio circles - ORCs - were only discovered last year in 2019 observations collected by the Australian Square Kilometre Array Pathfinder (ASKAP)., Radio Astronomy, , The discovery of a giant ghostly circle in extragalactic space is bringing us closer to understanding what these mysterious structures actually are., The so-called odd radio circle named ORC J0102-2450,   

    From Western Sydney University (AU) via Science Alert (AU) : “Astronomers Detect Another Mysterious Ghostly Circle in Extragalactic Space” 

    From Western Sydney University (AU)



    Science Alert (AU)

    29 APRIL 2021

    ORC J0102-2450, as seen with SKA ASKAP and overlaid onto other surveys. (Koribalski et al., arXiv, 2021)

    The discovery of a giant ghostly circle in extragalactic space is bringing us closer to understanding what these mysterious structures actually are.

    The so-called odd radio circle named ORC J0102-2450, joins just a handful of previously discovered space blobs. Given the low sample size, the new discovery adds important statistical data that suggest these objects could somehow be related to galaxies. The paper has been accepted into MNRAS Letters.

    Humanity has been staring up and wondering about the sky for tens of thousands of years, but even so, space retains many secrets. Odd radio circles – ORCs – were only discovered last year in 2019 observations collected by the Australian Square Kilometre Array Pathfinder (ASKAP), one of the world’s most sensitive radio telescopes.

    As the name suggests, they’re apparently giant circles of relatively faint light in radio wavelengths, appearing brighter around the edges, like bubbles. Although circular objects are relatively common in space, the ORCs seemed to correspond with no known phenomenon.

    Follow-up observations with a different telescope array confirmed the presence of two of the original three ORCs, while a fourth was soon found in data collected by yet another instrument. So, we can be pretty confident these aren’t the result of some ASKAP glitch or artifact, or a phenomenon local to the telescope (like the Murriyang microwave oven) either.

    We don’t know how far away the ORCs are, which makes their size hard to gauge, but finding more of them could give us more clues. That’s where ORC J0102-2450 enters the picture.

    ASKAP conducted a series of radio continuum observations between 2019 and December 2020. To find the ORC, a team led by astronomer Bärbel Koribalski of CSIRO-Commonwealth Scientific and Industrial Research Organisation (AU) and Western Sydney University in Australia combined eight of the radio continuum images, a process that reveals objects too faint to be seen in just one or two images.

    From the combined data, a faint ring emerged. Comparison with observations from other surveys revealed no radiation in other wavelengths than radio, which can help rule out some sources of the emission.

    Interestingly, however, almost bang in the center of the ORC the team found something: an elliptical radio galaxy named DES J010224.33-245039.5.

    Sure, this could be a coincidence – but two of the other four ORCs described last year also had an elliptical radio galaxy bang in the middle. The probability of finding a radio source randomly coincident with the center of an ORC is one in a couple of hundred, the researchers said – never mind finding three of the things.

    This suggests that the circles may have something to do with elliptical radio galaxies. We know that radio galaxies often have radio lobes, huge elliptical structures that only emit in radio wavelengths ballooning out on either side of the galactic nucleus. One possibility is that the ORCs are these lobes viewed end-on, so that they appear circular.

    The ORCs could also, the researchers noted, be the product of a giant blast wave from the central galaxy, but it would have to be truly giant, produced by something like the merger of two supermassive black holes.

    If either of these scenarios is the case, the link with the galaxy can help us work out the size of the ORC. In the case of ORC J0102-2450, we know the distance to DES J010224.33-245039.5. That distance gives us a rough size estimate for ORC J0102-2450 of around 980,000 light-years. If this size is confirmed, it could help us to learn more about radio lobes or blast waves.

    The third possibility the researchers considered is an interaction between a radio galaxy and the intergalactic medium, possibly involving DES J010224.33-245039.5, although this seemed relatively unlikely to be able to produce the observed ring, the team noted.

    Although the sample size is still extremely small, and we can’t tell anything for sure just yet, the discovery of ORC J0102-2450 points to some promising directions for future observation and analysis.

    If we can find even more ORCs, they should be able to help astronomers determine how common they are, and find more similarities between them that could further narrow down their potential formation mechanisms.

    Low-frequency radio observations and X-ray observations will be of particular interest, they noted.

    “The discovery of further ORCs in the rapidly growing amount of wide-field radio continuum data from ASKAP and other telescopes will show if the above scenarios have any merit, contributing to exciting times in astronomy,” the team wrote in their paper.

    See the full article here.


    Please help promote STEM in your local schools.

    Stem Education Coalition

    Western Sydney University (AU) , formerly the University of Western Sydney, is an Australian multi-campus university in the Greater Western region of Sydney, Australia. The university in its current form was founded in 1989 under the terms of the State Legislature “Western Sydney University Act 1997 No 116”, which created a federated network university with an amalgamation between the Nepean College of Advanced Education and the Hawkesbury Agricultural College. The Macarthur Institute of Higher Education was incorporated in the university in 1989. In 2001, the University of Western Sydney was restructured as a single multi-campus university rather than as a federation. In 2015, the university underwent a rebranding which resulted in a change in name from the University of Western Sydney to Western Sydney University. It is a provider of undergraduate, postgraduate, and higher research degrees with campuses in Bankstown, Blacktown, Campbelltown, Hawkesbury, Liverpool, Parramatta, and Penrith.

    In 2021, the QS World University Rankings ranks the university 474th in the world, coming 26th in Australia and 5th in Sydney. In 2021, it was ranked in the top 300 in the world and 18th in Australia in the Times Higher Education World University Rankings.

  • richardmitnick 12:42 pm on April 28, 2021 Permalink | Reply
    Tags: "The Discovery of 8 New Millisecond Pulsars", , , , Max Planck Institute for Radio Astronomy[MPG Institut für Radioastronomie](DE), Radio Astronomy   

    From Max Planck Institute for Radio Astronomy[MPG Institut für Radioastronomie](DE): “The Discovery of 8 New Millisecond Pulsars” 

    From Max Planck Institute for Radio Astronomy[MPG Institut für Radioastronomie](DE)

    Dr. Paulo Freire
    Phone:+49 228 525-496
    Max-Planck-Institut für Radioastronomie, Bonn

    Tasha Gautam
    Phone:+49 228 525-189
    Max-Planck-Institut für Radioastronomie, Bonn

    Dr. Norbert Junkes
    Press and Public Outreach
    Phone:+49 228 525-399
    Max-Planck-Institut für Radioastronomie, Bonn

    A group of astronomers, led by the INAF Italian National Institute for Astrophysics [Istituto Nazionale di Astrofisica](IT) and the Max Planck Institute for Radio Astronomy (MPIfR) in Bonn, Germany, has discovered 8 millisecond pulsars located within dense clusters of stars, known as “globular clusters”, using South Africa’s MeerKAT radio telescope.

    Millisecond pulsars are neutron stars, the most compact star known, that spin up to 700 times per second. This result comes from the synergic work of two international collaborations, TRAPUM and MeerTIME, with the findings detailed in a MNRAS paper published today.

    The globular cluster NGC 6624 was captured by the NASA/ESA Hubble Space Telescope [US]. Some of the pulsars hosted by the cluster have been highlighted in the inset: in red, the new pulsar PSR J1823-3021G, found by MeerKAT. The cluster NGC 6624 is located in the constellation of Sagittarius at just under 8000 light-years from the Sun.

    Millisecond pulsars are extremely compact stars mainly made up of neutrons, and are amongst the most extreme objects in the universe: they pack hundreds of thousands of times the mass of the Earth in a sphere with a diameter of about 24 km; they spin at a rate of hundreds of rotations per second. They emit a beam of radio waves that hits the observer at every rotation, like a lighthouse. The formation of these objects is highly enhanced in the star-rich environments at the centres of globular clusters.

    “We directed the MeerKAT antennas toward 9 globular clusters, and we discovered new pulsars in 6 of them”, says the lead author, Alessandro Ridolfi, a post-doctoral research fellow at INAF and MPIfR. Five of these new pulsars orbit around another star, and one of these, named PSR J1823-3021G, is particularly interesting: “Because of its highly elliptical orbit, and massive companion, this system is likely the result of an exchange of partners: following a ‘close encounter’: the original partner was expelled and replaced by a new companion star”, continues Ridolfi.

    Tasha Gautam, doctoral researcher at the MPIfR in Bonn and co-author of the paper, explains: “This particular pulsar could have a high mass, more than 2 times the mass of the Sun, or it could be the first confirmed system formed by a millisecond pulsar and a neutron star. If confirmed by current additional observations, this would make this millisecond pulsar a formidable laboratory for studying fundamental physics.”

    The 8 new pulsars are just the tip of the iceberg: the observations that led to their discovery used only about 40 of the 64 MeerKAT antennas and focused only on the central regions of the globular clusters.

    “The MeerKAT radio telescope is a huge technological step forward for the research and the study of pulsars in the southern sky”, says Andrea Possenti from INAF, coordinator of pulsar observations in globular clusters for the MeerTIME collaboration. “In the next few years, MeerKAT is expected to find dozens of new millisecond pulsars, giving us a foretaste of what will then happen with the advent of the mid-frequency antennas of the SKA Observatory, which will revolutionize many fields of astrophysics, including the study of pulsars.”

    Ridolfi, Gautam and Possenti are members of the TRAnsients and PUlsars with MeerKAT (TRAPUM) collaboration, a Large Survey Proposal with a broad international collaboration of astronomers excited by the possibilities opened up by MeerKAT. For this particular work, they shared telescope time with a second Large Survey Proposal for MeerKAT, MeerTIME, which is using MeerKAT to study already known pulsars with unprecedented precision.

    This work served as a testbed for the TRAPUM collaboration to better plan the fully-fledged globular cluster pulsar survey, which is currently underway and which makes use of all the current 64 dishes (thus further gaining in sensitivity). The survey will broaden the search to many more globular clusters, and will also survev their outer regions.

    “Past surveys for pulsars in globular clusters have discovered bizarre and extreme binary pulsars. Hopefully, with new instruments like MeerKAT we will discover even more extreme systems that can teach us more about the basic laws of our Universe”, concludes Paulo Freire, also a co-author from the MPIfR.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    MPIFR/Effelsberg Radio Telescope(DE)

    The Max Planck Institute for Radio Astronomy [MPG Institut für Radioastronomie] (DE) is located in Bonn, Germany. It is one of 80 institutes in the Max Planck Society.

    By combining the already existing radio astronomy faculty of the University of Bonn led by Otto Hachenberg with the new Max Planck institute the Max Planck Institute for Radio Astronomy was formed. In 1972 the 100-m radio telescope in Effelsberg was opened. The institute building was enlarged in 1983 and 2002.

    The institute was founded in 1966 by the Max-Planck-Gesellschaft as the “Max-Planck-Institut für Radioastronomie” (MPIfR).

    The foundation of the institute was closely linked to plans in the German astronomical community to construct a competitive large radio telescope in (then) West Germany. In 1964, Professors Friedrich Becker, Wolfgang Priester and Otto Hachenberg of the Astronomische Institute der Universität Bonn submitted a proposal to the Stiftung Volkswagenwerk for the construction of a large fully steerable radio telescope.

    In the same year the Stiftung Volkswagenwerk approved the funding of the telescope project but with the condition that an organization should be found, which would guarantee the operations. It was clear that the operation of such a large instrument was well beyond the possibilities of a single university institute.

    Already in 1965 the Max-Planck-Gesellschaft (MPG) decided in principle to found the Max-Planck-Institut für Radioastronomie. Eventually, after a series of discussions, the institute was officially founded in 1966.

    The MPG Society for the Advancement of Science (German: Max-Planck-Gesellschaft zur Förderung der Wissenschaften e. V.) is a formally independent non-governmental and non-profit association of German research institutes founded in 1911 as the Kaiser Wilhelm Society and renamed the Max Planck Society in 1948 in honor of its former president, theoretical physicist Max Planck. The society is funded by the federal and state governments of Germany as well as other sources.

    According to its primary goal, the Max Planck Society supports fundamental research in the natural, life and social sciences, the arts and humanities in its 83 (as of January 2014)[2] Max Planck Institutes. The society has a total staff of approximately 17,000 permanent employees, including 5,470 scientists, plus around 4,600 non-tenured scientists and guests. Society budget for 2015 was about €1.7 billion.

    The Max Planck Institutes focus on excellence in research. The Max Planck Society has a world-leading reputation as a science and technology research organization, with 33 Nobel Prizes awarded to their scientists, and is generally regarded as the foremost basic research organization in Europe and the world. In 2013, the Nature Publishing Index placed the Max Planck institutes fifth worldwide in terms of research published in Nature journals (after Harvard University(US), Massachusetts Institute of Technology(US), Stanford University(US) and the National Institutes of Health(US). In terms of total research volume (unweighted by citations or impact), the Max Planck Society is only outranked by the Chinese Academy of Sciences [中国科学院](CN), the Russian Academy of Sciences [ Pосси́йская; акаде́мия нау́к ;(РАН) Rossíiskaya akadémiya naúk](RU)and Harvard University. The Thomson Reuters-Science Watch website placed the Max Planck Society as the second leading research organization worldwide following Harvard University, in terms of the impact of the produced research over science fields.

  • richardmitnick 11:27 am on April 27, 2021 Permalink | Reply
    Tags: "ALMA Shows Massive Young Stars Forming in 'Chaotic Mess'", , , , , , Radio Astronomy   

    From ALMA [The Atacama Large Millimeter/submillimeter Array] (CL): “ALMA Shows Massive Young Stars Forming in ‘Chaotic Mess'” 

    From ALMA [The Atacama Large Millimeter/submillimeter Array] (CL)

    Nicolás Lira
    Education and Public Outreach Coordinator
    Joint ALMA Observatory, Santiago – Chile
    Phone: +56 2 2467 6519
    Cell phone: +56 9 9445 7726
    Email: nicolas.lira@alma.cl

    Masaaki Hiramatsu
    Education and Public Outreach Officer, NAOJ Chile
, Tokyo – Japan
    Phone: +81 422 34 3630
    Email: hiramatsu.masaaki@nao.ac.jp

    Bárbara Ferreira
    ESO Public Information Officer
    Garching bei München, Germany
    Phone: +49 89 3200 6670
    Email: pio@eso.org

    Amy C. Oliver
    Public Information & News Manager
    National Radio Astronomical Observatory (NRAO), USA
    Phone: +1 434 242 9584
    Email: aoliver@nrao.edu

    A team of astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) has taken a big step toward answering a longstanding question — do stars much more massive than the Sun form in the same way as their smaller siblings?

    Young, still-forming stars similar in mass to the Sun are observed gaining material from their surrounding clouds of gas and dust in a relatively orderly manner. The incoming material forms a disk orbiting the young star and that disk feeds the star at a pace it can digest. Condensations of material within the disk form planets that will remain after the star’s growth process is complete.

    The disks are commonly seen around young low-mass stars, but have not been found around much more massive stars in their forming stages. Astronomers questioned whether the process for the larger stars is simply a scaled-up version of that for the smaller ones.

    Artist’s conception illustrates process seen in forming stars much more massive than the Sun. At top left, material is being drawn into the young star through an orbiting disk which generates a fast-moving jet of material outward. At top right, material begins coming in from another direction, and at bottom left, begins deforming the original disk until, at bottom right, the disk orientation — and the jet orientation — have changed. Credit: Bill Saxton, National Radio Astronomy Observatory (US)/Associated Universities Inc (US)/National Science Foundation (US).

    ALMA image of the chaotic scene around a massive young protostar, in this case one called W51e2e. Grey shows dust close to the star, while the red and blue indicate material in the jets moving rapidly outward from the star. Red shows material moving away from Earth and blue material moving toward Earth. Credit: Goddi, Ginsburg, et al., Sophia Dagnello, NRAO/AUI/NSF.

    ALMA image of the chaotic scene around a massive young protostar, in this case one called W51north . Grey shows dust close to the star, while the red and blue indicate material in the jets moving rapidly outward from the star. Red shows material moving away from Earth and blue material moving toward Earth. Credit: Goddi, Ginsburg, et al., Sophia Dagnello, NRAO/AUI/NSF.

    ALMA image of the chaotic scene around a massive young protostar, in this case one called W51e8 . Grey shows dust close to the star, while the red and blue indicate material in the jets moving rapidly outward from the star. Red shows material moving away from Earth and blue material moving toward Earth. Credit: Goddi, Ginsburg, et al., Sophia Dagnello, NRAO/AUI/NSF.

    Credit: Goddi, Ginsburg, et al., S. Dagnello, B. Saxton, NRAO/AUI/NSF.

    “Our ALMA observations now provide compelling evidence that the answer is no,” said Ciriaco Goddi, of Radboud University [Radboud Universiteit](NL).

    Goddi led a team that used ALMA to study three high-mass, very young stars in a star-forming region called W51, about 17,000 light-years from Earth. They used ALMA when its antennas were spread apart to their farthest extent, providing resolving power capable of making images 10 times sharper than previous studies of such objects.

    They were looking for evidence of the large, stable disks seen orbiting smaller young stars. Such disks propel fast-moving jets of material outward perpendicular to the plane of the disk.

    “With ALMA’s great resolving power, we expected to finally see a disk. Instead, we found that the feeding zone of these objects looks like a chaotic mess,” said Adam Ginsburg of the University of Florida (US).

    The observations showed streamers of gas falling toward the young stars from many different directions. Jets indicated that there must be small disks that are yet unseen. In one case, it appears that some event actually flipped a disk about 100 years ago.

    The researchers concluded that these massive young stars form, at least in their very early stages, by drawing in material from multiple directions and at unsteady rates, in sharp contrast to the stable inflows seen in smaller stars. The multiple channels of incoming material, the astronomers said, probably prevent the formation of the large, steady disks seen around smaller stars.

    “Such a ‘disordered infall’ model was first proposed based on computer simulations, and we now have the first observational evidence supporting that model,” Goddi said.

    Additional Information

    Goddi, Ginsburg and their colleagues from the U.S., Mexico, and Europe reported their findings in The Astrophysical Journal.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

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

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

    NRAO Small
    ESO 50 Large

    ALMA is a time machine!

    ALMA-In Search of our Cosmic Origins

  • richardmitnick 10:58 pm on April 26, 2021 Permalink | Reply
    Tags: "Deciphering the lives of double neutron stars in radio and gravitational wave astronomy", , , , Caltech MIT Advanced aLIGO(US), , GW190425, Radio Astronomy   

    From ARC Centres of Excellence for Gravitational Wave Discovery OzGrav (AU) : “Deciphering the lives of double neutron stars in radio and gravitational wave astronomy” 


    From ARC Centres of Excellence for Gravitational Wave Discovery OzGrav (AU)


    Artist’s now iconic illustration of a double neutron star merger. Credit: A. Simonnet Caltech MIT Advanced aLIGO(US), Sonoma State University (US).

    Scientists from the ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav) have described a way to determine the birth population of double neutron stars–some of the densest objects in the Universe formed in collapsing massive stars. The recently published study [The Astrophysical Journal Letters] observed different life stages of these neutron star systems.

    Scientists can observe the merging of double neutron star systems using gravitational waves–ripples in the fabric of space and time. By studying neutron star populations, scientists can learn more about how they formed and evolved. So far, there have been only two double neutron star systems detected by gravitational-wave detectors; however, many of them have been observed in radio astronomy.

    One of the double neutron stars observed in gravitational wave signals, called GW190425, is far more massive than the ones in typical Galactic populations observed in radio astronomy, with a combined mass of 3.4 times that of our Sun.

    This raises the question: why is there a lack of these massive double neutron stars in radio astronomy? To find an answer, OzGrav PhD student Shanika Galaudage, from Monash University (AU), investigated how to combine radio and gravitational-wave observations.

    The birth, mid-life and deaths of double neutron stars.

    Radio and gravitational-wave astronomy enables scientists to study double neutron stars at different stages of their evolution. Radio observations probe the lives of double neutron stars, while gravitational waves study their final moments of life. To achieve a better understanding of these systems, from formation to merger, scientists need to study the connection between radio and gravitational wave populations: their birth populations.

    Shanika and her team determined the birth mass distribution of double neutron stars using radio and gravitational-wave observations. “Both populations evolve from the birth populations of these systems, so if we look back in time when considering the radio and gravitational-wave populations we see today, we should be able to extract the birth distribution,” says Shanika Galaudage.

    The key is to understand the delay-time distribution of double neutron stars: the time between the formation and merger of these systems. The researchers hypothesised that heavier double neutron star systems may be fast-merging systems, meaning that they’re merging too fast to be visible in radio observations and could only be seen in gravitational-waves.

    GW190425 and the fast-merging channel.

    The study found mild support for a fast-merging channel, indicating that heavy double neutron star systems may not need a fast-merging scenario to explain the lack of observations in radio populations. “We find that GW190425 is not an outlier when compared to the broader population of double neutron stars,” says study co-author Christian Adamcewicz, from Monash University. “So, these systems may be rare, but they‘re not necessarily indicative of a separate fast-merging population.”

    In future gravitational wave detections, researchers can expect to observe more double neutron star mergers. “If future detections reveal a stronger discrepancy between the radio and gravitational-wave populations, our model provides a natural explanation for why such massive double neutron stars are not common in radio populations,” adds co-author Dr Simon Stevenson, an OzGrav postdoctoral researcher at Swinburne University of Technology (AU).

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    OzGrav (AU)

    ARC Centres of Excellence for Gravitational Wave Discovery OzGrav (AU)
    A new window of discovery.
    A new age of gravitational wave astronomy.
    One hundred years ago, Albert Einstein produced one of the greatest intellectual achievements in physics, the theory of general relativity. In general relativity, spacetime is dynamic. It can be warped into a black hole. Accelerating masses create ripples in spacetime known as gravitational waves (GWs) that carry energy away from the source. Recent advances in detector sensitivity led to the first direct detection of gravitational waves in 2015. This was a landmark achievement in human discovery and heralded the birth of the new field of gravitational wave astronomy. This was followed in 2017 by the first observations of the collision of two neutron-stars. The accompanying explosion was subsequently seen in follow-up observations by telescopes across the globe, and ushered in a new era of multi-messenger astronomy.

    The mission of the ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav) is to capitalise on the historic first detections of gravitational waves to understand the extreme physics of black holes and warped spacetime, and to inspire the next generation of Australian scientists and engineers through this new window on the Universe.

    OzGrav is funded by the Australian Government through the Australian Research Council Centres of Excellence funding scheme, and is a partnership between Swinburne University of Technology (AU) (host of OzGrav headquarters), the Australian National University (AU), Monash University (AU), University of Adelaide (AU), University of Melbourne (AU), and University of Western Australia (AU), along with other collaborating organisations in Australia and overseas.

    The objectives for the ARC Centres of Excellence 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

    develope 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.

  • richardmitnick 2:24 pm on April 26, 2021 Permalink | Reply
    Tags: "Complex organic molecules detected in the starless core Lynds 1521E", , , , , , , Radio Astronomy,   

    From University of Arizona via phys.org : “Complex organic molecules detected in the starless core Lynds 1521E” 

    From University of Arizona



    L1521E: A map of the average line-of-sight dust temperature (color scale) and column density (contours) determined from SED fitting of Herschel Space Observatory. Credit: Scibelli et al., 2021.

    Using the ARO 12-m telescope, astronomers have investigated a young starless core known as Lynds 1521E (or L1521E). The study resulted in the detection of complex organic molecules in this object. The finding is detailed in a paper April 15 in MNRAS.

    Starless cores are dense, cold regions within interstellar molecular clouds. They represent the earliest observable stage of low-mass star formation. Observations show that even in such cold environments, complex organic molecules can be present. Finding these molecules in starless cores could help us better understand the processes of stellar formation and evolution.

    L1521E is a dynamically and chemically young starless core in the Taurus Molecular Cloud, one of the two known in this cloud. It has a modest central density of around 200,000−300,000 cm−3 and it is assumed that it can only have existed at its present density for less than 100,000 years, which makes it one of the youngest starless cores so far detected and an excellent object to study how complex organic molecules form.

    So a group of astronomers led by Samantha Scibelli of the University of Arizona searched for complex organic molecules in L1521E using the 12-meter telescope of the Arizona Radio Observatory (ARO), with promising results.

    “Molecular line observations were made with the ARO 12m telescope during three separate seasons, two years apart, using two different backend receivers. The first observing shifts between January 12, 2017 and April 27, 2017 with 10 tunings between 84 and 102 GHz (3.6 − 2.9mm),” the researchers explained.

    The observations detected dimethyl ether (CH3OCH3), methyl formate (HCOOCH3), and vinyl cyanide (CH2CHCN). Additionally, the study identified eight transitions of acetaldehyde (CH3CHO) and seven transitions of vinyl cyanide.

    The study confirmed that the estimated chemical age of L1521E is indeed young, as complex organic molecules first peak at about 60,000 years. This is consistent with the carbon monoxide (CO) depletion age of this starless core.

    The astronomers note that the detected abundances of complex organic molecules for L1521E are in general underestimated. This suggests that a desorption mechanism is missing, or the current description of the already considered mechanisms should be revised by further studies.

    All in all, the results obtained by the team seem to suggest that complex organic molecules observed in cold gas formed not only in gas-phase reactions, but also on surfaces of interstellar grains. The new findings could also have implications for future studies of starless cores.

    The detection of a rich COM [complex organic molecules] chemistry in young cold core L1521E presents an interesting challenge for future modeling efforts, requiring some type of unified approach combining cosmic-ray chemistry, reactive desorption and non-diffusive surface reactions,” the astronomers concluded.

    See the full article here .

    Please help promote STEM in your local schools.

    Stem Education Coalition

    As of 2019, the University of Arizona enrolled 45,918 students in 19 separate colleges/schools, including the UArizona College of Medicine in Tucson and Phoenix and the James E. Rogers College of Law, and is affiliated with two academic medical centers (Banner – University Medical Center Tucson and Banner – University Medical Center Phoenix). UArizona is one of three universities governed by the Arizona Board of Regents. The university is part of the Association of American Universities and is the only member from Arizona, and also part of the Universities Research Association(US). The university is classified among “R1: Doctoral Universities – Very High Research Activity”.

    Known as the Arizona Wildcats (often shortened to “Cats”), the UArizona’s intercollegiate athletic teams are members of the Pac-12 Conference of the NCAA. UArizona athletes have won national titles in several sports, most notably men’s basketball, baseball, and softball. The official colors of the university and its athletic teams are cardinal red and navy blue.

    After the passage of the Morrill Land-Grant Act of 1862, the push for a university in Arizona grew. The Arizona Territory’s “Thieving Thirteenth” Legislature approved the UArizona in 1885 and selected the city of Tucson to receive the appropriation to build the university. Tucson hoped to receive the appropriation for the territory’s mental hospital, which carried a $100,000 allocation instead of the $25,000 allotted to the territory’s only university (Arizona State University(US) was also chartered in 1885, but it was created as Arizona’s normal school, and not a university). Flooding on the Salt River delayed Tucson’s legislators, and by they time they reached Prescott, back-room deals allocating the most desirable territorial institutions had been made. Tucson was largely disappointed with receiving what was viewed as an inferior prize.

    With no parties willing to provide land for the new institution, the citizens of Tucson prepared to return the money to the Territorial Legislature until two gamblers and a saloon keeper decided to donate the land to build the school. Construction of Old Main, the first building on campus, began on October 27, 1887, and classes met for the first time in 1891 with 32 students in Old Main, which is still in use today. Because there were no high schools in Arizona Territory, the university maintained separate preparatory classes for the first 23 years of operation.


    UArizona is classified among “R1: Doctoral Universities – Very high research activity”. UArizona is the fourth most awarded public university by National Aeronautics and Space Administration(US) for research. UArizona was awarded over $325 million for its Lunar and Planetary Laboratory (LPL) to lead NASA’s 2007–08 mission to Mars to explore the Martian Arctic, and $800 million for its OSIRIS-REx mission, the first in U.S. history to sample an asteroid.

    The LPL’s work in the Cassini spacecraft orbit around Saturn is larger than any other university globally. The UArizona laboratory designed and operated the atmospheric radiation investigations and imaging on the probe. UArizona operates the HiRISE camera, a part of the Mars Reconnaissance Orbiter. While using the HiRISE camera in 2011, UArizona alumnus Lujendra Ojha and his team discovered proof of liquid water on the surface of Mars—a discovery confirmed by NASA in 2015. UArizona receives more NASA grants annually than the next nine top NASA/JPL-Caltech(US)-funded universities combined. As of March 2016, the UArizona’s Lunar and Planetary Laboratory is actively involved in ten spacecraft missions: Cassini VIMS; Grail; the HiRISE camera orbiting Mars; the Juno mission orbiting Jupiter; Lunar Reconnaissance Orbiter (LRO); Maven, which will explore Mars’ upper atmosphere and interactions with the sun; Solar Probe Plus, a historic mission into the Sun’s atmosphere for the first time; Rosetta’s VIRTIS; WISE; and OSIRIS-REx, the first U.S. sample-return mission to a near-earth asteroid, which launched on September 8, 2016.

    UArizona students have been selected as Truman, Rhodes, Goldwater, and Fulbright Scholars. According to The Chronicle of Higher Education, UArizona is among the top 25 producers of Fulbright awards in the U.S.

    UArizona is a member of the Association of Universities for Research in Astronomy(US), a consortium of institutions pursuing research in astronomy. The association operates observatories and telescopes, notably Kitt Peak National Observatory(US) just outside Tucson. Led by Roger Angel, researchers in the Steward Observatory Mirror Lab at UArizona are working in concert to build the world’s most advanced telescope. Known as the Giant Magellan Telescope(CL), it will produce images 10 times sharper than those from the Earth-orbiting Hubble Telescope.

    Giant Magellan Telescope, 21 meters, to be at the NOIRLab(US) National Optical Astronomy Observatory(US) Carnegie Institution for Science’s(US) Las Campanas Observatory(CL), some 115 km (71 mi) north-northeast of La Serena, Chile, over 2,500 m (8,200 ft) high.

    The telescope is set to be completed in 2021. GMT will ultimately cost $1 billion. Researchers from at least nine institutions are working to secure the funding for the project. The telescope will include seven 18-ton mirrors capable of providing clear images of volcanoes and riverbeds on Mars and mountains on the moon at a rate 40 times faster than the world’s current large telescopes. The mirrors of the Giant Magellan Telescope will be built at UArizona and transported to a permanent mountaintop site in the Chilean Andes where the telescope will be constructed.

    Reaching Mars in March 2006, the Mars Reconnaissance Orbiter contained the HiRISE camera, with Principal Investigator Alfred McEwen as the lead on the project. This National Aeronautics and Space Administration(US) mission to Mars carrying the UArizona-designed camera is capturing the highest-resolution images of the planet ever seen. The journey of the orbiter was 300 million miles. In August 2007, the UArizona, under the charge of Scientist Peter Smith, led the Phoenix Mars Mission, the first mission completely controlled by a university. Reaching the planet’s surface in May 2008, the mission’s purpose was to improve knowledge of the Martian Arctic. The Arizona Radio Observatory(US), a part of UArizona Department of Astronomy Steward Observatory(US), operates the Submillimeter Telescope on Mount Graham.

    The National Science Foundation(US) funded the iPlant Collaborative in 2008 with a $50 million grant. In 2013, iPlant Collaborative received a $50 million renewal grant. Rebranded in late 2015 as “CyVerse”, the collaborative cloud-based data management platform is moving beyond life sciences to provide cloud-computing access across all scientific disciplines.
    In June 2011, the university announced it would assume full ownership of the Biosphere 2 scientific research facility in Oracle, Arizona, north of Tucson, effective July 1. Biosphere 2 was constructed by private developers (funded mainly by Texas businessman and philanthropist Ed Bass) with its first closed system experiment commencing in 1991. The university had been the official management partner of the facility for research purposes since 2007.

    U Arizona mirror lab-Where else in the world can you find an astronomical observatory mirror lab under a football stadium?

    University of Arizona’s Biosphere 2, located in the Sonoran desert. An entire ecosystem under a glass dome? Visit our campus, just once, and you’ll quickly understand why the UA is a university unlike any other.

Compose new post
Next post/Next comment
Previous post/Previous comment
Show/Hide comments
Go to top
Go to login
Show/Hide help
shift + esc
%d bloggers like this: