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  • richardmitnick 8:16 am on September 24, 2020 Permalink | Reply
    Tags: "The ring around the black hole glitters", , , , , , , Max Planck Institute for Radio Astronomy   

    From Max Planck Institute for Radio Astronomy: “The ring around the black hole glitters” 


    From Max Planck Institute for Radio Astronomy

    September 23, 2020

    Dr. Norbert Junkes
    Press and public relations
    Max Planck Institute for Radio Astronomy, Bonn
    +49 2 28525-399
    njunkes@mpifr-bonn.mpg.de

    Prof. Dr. J. Anton Zensus
    Max Planck Institute for Radio Astronomy, Bonn
    +49 228 525-378
    azensus@mpifr-bonn.mpg.de

    Astronomers of the Event Horizon Telescope conclude from archive data how the surroundings of the mass monster in the galaxy M 87 have changed.

    In the center of the giant galaxy Messier 87 lurks a giant black hole.

    Messier 87*, The first image of a black hole. This is the supermassive black hole at the center of the galaxy Messier 87. Image via JPL/ Event Horizon Telescope Collaboration.

    The image of this mass monster published last year and obtained with the Event Horizon Telescope (EHT) went around the world.

    EHT map

    Now the EHT team has analyzed archive data from 2009 to 2013, some of which are still unpublished. The researchers found that the ring-shaped shadow around the black hole is indeed always present, but changes its orientation and brightness distribution – the ring seems to be glittering. The participation of the European APEX telescope in Chile and the IRAM 30-meter telescope co-financed by the Max Planck Society on Pico Veleta in the Spanish Sierra Nevada played an important part in this discovery.

    ESO/MPIfR APEX high on the Chajnantor plateau in Chile’s Atacama region, at an altitude of over 4,800 m (15,700 ft).

    IRAM 30m Radio telescope, on Pico Veleta in the Spanish Sierra Nevada,, Altitude 2,850 m (9,350 ft).

    2
    Snapshots of the M 87* black hole obtained through imaging / geometric modeling, and the EHT array of telescopes in 2009 – 2017. The diameter of all rings is similar, but the location of the bright side varies. The variation of the thickness of the ring is most likely not real and results from the limited number of participating observatories in earlier experiments. © M. Wielgus, D. Pesce & EHT Collaboration.

    “The results announced in April 2019 show an image of the shadow of a black hole, consisting of a bright ring formed by hot plasma swirling around the black hole in Messier 87, and a dark central part, where we expect the event horizon to be”, reminds Maciek Wielgus, astronomer at Harvard University, and lead author of the new paper.

    However, those results were based only on observations performed throughout a one-week long time window in April 2017, which is far too short to see if the ring is evolving over longer time scales. Even after careful data analysis, therefore some open questions with regard to the stationarity of the ring features over time remained. For that reason, an investigation of earlier archival data was considered.

    The 2009 – 2013 observations consist of far less data than the ones performed in 2017, making it hard to image Messier 87 without a-priori assumptions. For the available archive data, the EHT team used statistical modeling based on geometrical assumptions to look at changes in the appearance of the black hole in M 87 (M 87*) over time.

    Expanding the analysis to the 2009-2017 observations, scientists have shown that Messier 87* adheres to theoretical expectations. The black hole’s shadow diameter has remained consistent with the prediction of Einstein’s theory of general relativity for a black hole of 6.5 billion solar masses. The morphology of an asymmetric ring persists on timescales of several years, in a consistent manner which provides additional confidence about the nature of M 87* and the origin of its shadow.

    But while the diameter of the ring remained constant over time, the EHT team found that the data were hiding a surprise. Thomas Krichbaum, astronomer at the Max Planck Institute for Radio Astronomy and one of the leading authors of the publication, says: “The data analysis suggests that the orientation and fine structure of the ring varies with time. This gives a first impression on the dynamical structure of the accretion flow, which surrounds the event horizon”. He adds: “Studying this region will be crucial for a better understanding of how black holes accrete matter and launch relativistic jets.”

    The gas falling onto a black hole heats up to billions of degrees, ionizes and becomes turbulent in the presence of magnetic fields. Since the flow of matter is turbulent, the ring brightness appears to glittering with time, which challenges some theoretical models of accretion.

    “The monitoring of the time variable structure of Messier 87 with the EHT is a challenge that will keep us busy over the next few years,” says Anton Zensus, Director at the Max Planck Institute for Radio Astronomy and Founding Chairman of the EHT Collaboration Board. „We are working in the analysis of the 2018 data, and preparing newer observations in 2021, with the addition of new sites such as the NOEMA Observatory in France, the most powerful radio telescope of its kind in the Northern Hemisphere and also co-financed by the Max-Plack-Gesellschaft as well as the Greenland Telescope, and Kitt Peak in Arizona,” adds Zensus.

    IRAM NOEMA in the French Alps on the wide and isolated Plateau de Bure at an elevation of 2550 meters, the telescope currently consists of ten antennas, each 15 meters in diameter.interferometer, Located in the French Alpes on the wide and isolated Plateau de Bure at an elevation of 2550 meters.

    NSF CfA Greenland telescope, at the Summit Station research camp, located at the highest point of the Greenland ice sheet at an altitude of 3,210 meters (10,530 feet).

    ARO 12m Radio Telescope, Kitt Peak National Observatory, In the Arizona-Sonoran Desert on the Tohono O’odham Nation Arizona USA, Altitude 1,914 m (6,280 ft).

    The enhanced imaging capabilities provided by this extended array will provide a more detailed view on the shadow of the black hole Messier 87* and on the innermost jet of the Messier 87 radio galaxy.

    Science paper:
    Monitoring the Morphology of M87* in 2009–2017 with the Event Horizon Telescope
    The Astrophysical Journal


    Cosmic twinkling. An animation representing one year of Messier 87* image evolution according to numerical simulations. Measured position angle is shown along with a 42 microarcsecond ring. For a part of the animation, image blurred to the EHT resolution is shown. © G. Wong, B. Prather, Ch. Gammie, M. Wielgus & EHT Collaboration.

    See the full article here .
    See also the full article from MIT Haystack here.

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    Please help promote STEM in your local schools.

    Stem Education Coalition



    MPIFR/Effelsberg Radio Telescope, Germany

    The Max Planck Institute for Radio Astronomy (German: Max-Planck-Institut für Radioastronomie) 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 Max Planck Society for the Advancement of Science (German: Max-Planck-Gesellschaft zur Förderung der Wissenschaften e. V.; abbreviated MPG) 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, MIT, Stanford and the US NIH). In terms of total research volume (unweighted by citations or impact), the Max Planck Society is only outranked by the Chinese Academy of Sciences, the Russian Academy of Sciences 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 8:18 pm on September 17, 2020 Permalink | Reply
    Tags: "Astronomy became big here", , , , , Max Planck Institute for Radio Astronomy, , ,   

    From Max Planck Institute for Radio Astronomy: “Astronomy became big here” 


    From Max Planck Institute for Radio Astronomy

    September 16, 2020

    Prof. Dr. Michael Kramer
    Max Planck Institute for Radio Astronomy, Bonn
    +49 228 525-278
    mkramer@mpifr-bonn.mpg.de

    Dr. Robert Adam
    Southafrican Radioastronomy Observatory, Kapstadt
    rob@ska.ac.za

    The Max Planck Society is investing 20 million Euros in the expansion of the radio telescope MeerKAT in South Africa, which will also be the nucleus of the Square Kilometre Array (SKA).

    Both partners, Germany and South Africa, benefit from the MeerKAT collaboration.

    SKA Square Kilometer Array

    SKA South Africa.

    SKA SARAO Meerkat telescope, South African design.

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

    SKA will be built in South Africa and Australia and, with a total area of eventually one square kilometre, will capture radio waves in the southern sky. We talked to Robert Adam, Managing Director of the South African Radio Astronomy Observatory (SARAO), and Michael Kramer Director at the Max Planck Institute for Radio Astronomy, about the scientific successes and goals of MeerKAT, the status of SKA and the prospects for science in South Africa and other countries in southern Africa.

    Contacts
    Prof. Dr. Michael Kramer
    Max Planck Institute for Radio Astronomy, Bonn +49 228 525-278 mkramer@mpifr-bonn.mpg.de
    Dr. Robert Adam
    rob@ska.ac.za Southafrican Radioastronomy Observatory, Kapstadt

    September 16, 2020

    Interview by Peter Hergersberg

    Prof. Kramer, Dr. Adam, which scientific highlights have been achieved with MeerKAT so far?

    Kramer: Already the first image of MeerKAT was the most detailed and most impressive image of our Galactic centre so far. MeerKAT has thus already proven that it is the best radio telescope currently available in the world. We have also already discovered several pulsars in globular clusters, which we are now investigating more closely. But we are only at the beginning and are very much looking forward to what we all can do with MeerKAT in the future.

    Adam: MeerKAT was only commissioned in mid-2018. In the beginning we first had to get the technology up and running to add the signals from the various antennas coherently – this is an unruly electronic monster. Nevertheless, there were already a number of highlights, for example insight into the jets emerging from the centres of various galaxies. But the large survey projects, for which MeerKAT is particularly well suited, have only just begun.

    What insights do you hope to gain from the survey projects?

    Adam: Two projects are about pulsars, which emit radio signals at very regular intervals, about their discovery and their timing. In other projects we are creating maps of the neutral hydrogen distribution. Hydrogen is the most common element in the Universe. Its distribution tells us a lot about the structure of the Universe, both on a cosmological and galactic scale. In addition, we study exoplanets orbiting nearby stars, or giant cosmic magnetic fields that still leave us with great mysteries.

    What benefit do you expect from the expansion by twenty antennas?

    Adam: Not only the sensitivity will increase considerably, but also the resolving power of the telescope will be much better. On the South African side we will equip the antennas with receivers, which will be able to map neutral hydrogen with higher resolution. Our German partners will also install “S-band” detectors on the new antennas, just as they have done with the existing telescopes.

    What are these “S-band” receivers for?

    Kramer: These receivers allow us to measure at slightly higher frequencies and therefore to look much deeper into our Galaxy – at lower frequencies the interstellar medium obstructs our view somewhat. So we can search for pulsars or observe chemical reactions. We are planning projects that will have a legacy value even when the even larger SKA, the Square Kilometre Array, comes along.

    Germany has not officially participated in SKA since 2015, but is still represented by the Max Planck Society? What is the status of this project?

    Kramer: The Max-Planck Society is currently acting in the kind of a placeholder role for German community in the SKA project. The society is negotiating right now how German scientists can benefit from the MPG contributions to the SKA.

    Adam: The Covid 19 pandemic has slowed the process of setting up the SKA Observatory somewhat, mainly due to travel restrictions. In general, SKA as a multilateral project is more difficult to coordinate than MeerKAT. I have the feeling that the effort for such processes increases quadratically with the number of partners: Not everyone has the money available at the same time, the scientists have promised their governments different things in some cases – you have to take all this into account if you want to get such a project off the ground. You often have to make compromises and cannot simply decide. But we are still on the right track. I think that as soon as the host countries Australia, South Africa and Great Britain as the largest donors have agreed, many things will become easier. China and Italy are also involved, and Germany will hopefully be involved again soon.

    Kramer: The good thing is that SKA is a modular system. That’s why you can add antennas step by step. Similar to what we are doing now with MeerKAT. Even if there were not sufficient money at the beginning for the complete expansion, you can already build a telescope that is unique. Then you can add more dishes to telescope when more partners join.

    Adam: It is definitely an advantage of radio astronomy that you can build our telescopes step by step. In comparison it’s very difficult to build half an optical telescope.

    To what extent do your two organisations benefit from the cooperation?

    Kramer: The Southern hemisphere is very interesting for radio astronomy, but there was no radio telescope of this size before MeerKAT. This very sensitive and versatile instrument opens up completely new possibilities for science in terms of sensivitiy and resolution. To be involved in this means what the Max Planck Society stands for: the attempt to push the limits of the possible again and again and thereby gain insight.

    Adam: In optical astronomy we have always been quite strong, but in radio astronomy our country is still a newcomer. That is why working with German colleagues on the expansion of MeerKat is highly beneficial for us, because we can build on their scientific experience. This will also help us to build SKA. And we are grateful for the unbureaucratic, cooperative manner of our German colleagues: We solve problems and do not look for ways to fall over them – an experience that we have encountered differently in other cooperations.

    Kramer: Apart from the science, we are always impressed by the smart out-of-the-box solutions that South African engineers come up with. For example, South African colleagues have developed hardware to combine all the telescopes’ data. It is now used more or less in this form in many other telescopes around the world, for example in our telescope in Effelsberg, and this even before we decided to join MeerKAT. The exchange of experiences and ideas therefore goes in both directions.

    What significance do MeerKAT and later SKA have for science in South Africa and beyond?

    Adam: After we left apartheid behind, we had the opportunity to reinvent many things. Before that there was a boycott of scientific institutions, as well as of trade and other things. Now we could suddenly cooperate internationally, especially international investment in our science became possible. So we thought about what could attract scientists from Germany or the USA to South Africa, not as a donor country, but as a country looking for benefits for its own research. That’s how we came to astronomy, because it’s always helpful to look at the Universe from different parts of the world. So we wanted to become hosts for different large telescopes. That’s why we first built the South African Large Telescope, an optical telescope, and then, in Namibia, which belonged to South Africa until 1990, we collaborated in the construction of the the gamma-ray telescope HESS. At SKA we also use international interest and international investment to support South African science and business. We told our cabinet: If you put your money into intelligent people in a great project, you will get more than the project. Silicon Valley would not exist without the Apollo project either. There is a whole range of transfers across disciplines. We can’t tell you what effect it will have, but it will have an effect. And in dealing with Big Data, a key technology not only for astronomy, but for a whole range of areas, we are actually pushing development forward today.

    Kramer: There is another good example of a very recent technology transfer: SARAO engineers were hired to build ventilators for the therapy of Covid-19. This shows that people are acquiring skills in our research that are useful for society.

    Adam: Of course we chose the Karoo area for MeerKAT because only a few people live there as dense populations are not compatible with astronomy. In radio astronomy, for example, there is interference from mobile phones. But of course there are also people in the Karoo region who, until the start of the MeerKAT project, lived exclusively on agriculture and government aid. We have contributed to diversifying the local economy, for example through hospitality or by selling vehicles and diesel. In addition, it is of course much more sensible to train young people from the area as craftsmen and technicians. An example from the lower tech services: all the workers who splice fibre are from the area. You can start at that level and then hopefully get further qualifications. After all, we have a large scholarship programme for pupils. And for students who finish high school and have good grades in science and mathematics, we pay for busaries.

    How do you assess the prospects for science in South Africa?

    Adam: South African science has developed in different stages. In the beginning, astronomy actually became big here, but later science focused on our resources: agricultural research, mining science. When we industrialised after the Second World War, the prevailing view was that we should concentrate on research that would help the development of industry. During apartheid, the focus was on security research, nuclear technology and energy security. This is how competences in quite different fields have developed over the decades.

    What was the situation after the end of apartheid?

    Adam: Overall I am optimistic about science in South Africa. We have strong research institutions and above all good universities. You have to remember that we came out of a phase where the fight for human rights was at stake. And then we told the Finance Minister that we needed money for basic research. That was not easy to sell, given the development agenda in the 1990s and 2000s. But we managed to do so because we attracted a number of large projects such as SKA to our country, which touch on many interests. SKA concerns not only the Ministry of Science, but also the Ministries of Communications, International Relations and Trade. As soon as several ministries are interested in a matter, it becomes much easier to implement it. Platforms such as MeerKAT are advantageous in this respect, which can be used not only by South African research but also by an international scientific community: Then someone else pays the salaries of the scientists. Above all, we have to provide the technology.

    Kramer: Our South African colleagues are now living the idea that the Max Planck Society also stands for. You never know what will come out of basic research. There may be major breakthroughs that change the world. Apart from that, it’s also about educating people. Not all of them are going to find a job in science. But young people learn here to solve problems that nobody has solved before, and they can bring that to the table in other places. This is another reason why basic research is so essential for every society and every economy. The South African colleagues have taken this very much to heart.

    How do they assess the chance that basic research will become a motor for development in other countries of Southern Africa?

    Adam: Basic research can mean very different things: There is basic research in agriculture or in genetics that is relevant to agriculture. But it will certainly be some time before we reach a research density in Southern Africa that is the basis of an innovation-driven economy. Even many better developed countries are not yet ready. And because the density of scientific activity is lower in developing countries, researchers there look less to industry next door rather than to that in the northern hemisphere. This makes the transfer to applications here even more difficult. Another problem with research’s contribution to economic development is that science often concentrates knowledge rather than disseminating it. Even the third industrial revolution, digitalization, which we hoped would make societies more democratic, did not succeed. No one has yet solved the problem of how to transform scientific knowledge into progress that benefits everyone. After all, there have been some breakthroughs in mining technology in South Africa that have created billions of dollars in global value creation. But when it comes to technology transfer, even in South Africa, we are not yet at the point where we would like to be.

    Kramer: Of course, none of us believes that astronomy will solve the world’s problems, but we can help at least a little bit. Big Data, for example, is not only a problem for astronomy. But we may already have a little more experience in this field than other disciplines. When our S-band detectors are running, we will produce two petabytes of data every night, which cannot be stored anywhere. In general, the storage of data of any kind will in future account for a considerable proportion of global energy consumption. So we have to try to make computers greener. We are still lucky in South Africa: although MeerKAT is located in a rather remote area, we can simply connect it to the power grid. But for other parts of telescopes like SKA we may have to develop an independent renewable energy supply that is available around the clock.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    Max Planck Institute for Radio Astronomy Bonn Germany.

    MPIFR/Effelsberg Radio Telescope, in the Ahrgebirge (part of the Eifel) in Bad Münstereifel, Germany.

    The Max Planck Institute for Radio Astronomy (German: Max-Planck-Institut für Radioastronomie) is located in Bonn, Germany. It is one of 80 institutes in the

     
  • richardmitnick 4:57 pm on August 18, 2020 Permalink | Reply
    Tags: "Magnetized gas flows feed a young star cluster", , , , , Max Planck Institute for Radio Astronomy, NASA/DLR SOFIA/High-resolution Airborne Wideband Camera-Plus HAWC+ Camera,   

    From Max Planck Institute for Radio Astronomy: “Magnetized gas flows feed a young star cluster” 


    From Max Planck Institute for Radio Astronomy

    August 18, 2020

    Dr. Thushara Pillai
    tpillai@bu.edu
    Boston University, Boston, USA

    Prof. Dr. Karl M. Menten
    Direktor und Leiter der Forschungsabteilung “Millimeter- und Submillimeter-Astronomie”
    Phone:+49 228 525-297

    Prof. Dr. Karl M. Menten
    Direktor und Leiter der Forschungsabteilung “Millimeter- und Submillimeter-Astronomie”
    Phone:+49 228 525-297
    kmenten@mpifr-bonn.mpg.de

    Dr. Norbert Junkes
    Press and Public Outreach
    Phone:+49 228 525-399
    njunkes@mpifr-bonn.mpg.de

    NASA/DLR SOFIA

    NASA SOFIA High-resolution Airborne Wideband Camera-Plus HAWC+ Camera

    Observations of magnetic fields in interstellar clouds made of gas and dust indicate that these clouds are strongly magnetized, and that magnetic fields influence the formation of stars within them. A key observation is that the orientation of their internal structure is closely related to that of the magnetic field.

    To understand the role of magnetic fields, an international research team led by Thushara Pillai, Boston University & Max Planck Institute for Radio Astronomy (MPIfR) in Bonn, Germany, observed the filamentary network of the dense gas surrounding a young star cluster in the solar neighboorhood, with the HAWC+ polarimeter on the airborne observatory SOFIA at infrared wavelengths. Their research shows that not all dense filaments are created equal. In some of the filaments the magnetic field succumbs to the flow of matter and is pulled into alignment with the filament. Gravitational force takes over in the denser parts of some filaments and the resulting weakly magnetized gas flow can feed the growth of young stellar clusters like a conveyor belt.

    The results are published in this week’s issue of Nature Astronomy.

    1
    Composite image of the Serpens South Cluster. Magnetic fields observed by SOFIA are shown as streamlines over an image from the Spitzer Space Telescope. SOFIA indicate that gravity can overcome some of the strong magnetic fields to deliver material needed for new stars. The magnetic fields have been dragged into alignment with the most powerful flows, as seen in the lower left where the streamlines are following the direction of the narrow, dark filament. This is accelerating the flow of material from interstellar space into the cloud, and fueling the collapse needed to spark star formation.
    © NASA/SOFIA/T. Pillai/J. Kauffmann; NASA/JPL-Caltech/L. Allen

    It is understood from theoretical simulations and observations that the filamentary nature of molecular clouds actually plays a major role in channeling mass from the larger interstellar medium into young stellar clusters whose growth is fed from the gas. The formation and evolution process of stars is expected to be driven by a complex interplay of several fundamental forces — namely turbulence, gravity, and the magnetic field. In order to get an accurate description for how dense clusters of stars form, astronomers need to pin down the relative role of these three forces. Turbulent gas motions as well as the mass content of filaments (and therefore gravitation force) can be gauged with relative ease. However, the signature of the interstellar magnetic field is weak, also because it is about 10,000–times weaker than even our own Earth’s magnetic field. This has made measurements of magnetic field strengths in filaments a formidable task.

    “The magnetic field directions in this new polarization map of Serpens South align well with the direction of gas flow along the narrow southern filament. Together these observations support the idea that filamentary accretion flows can help form a young star cluster”, adds Phil Myers from the Harvard-Smithsonian Center for Astrophysics, a co-author of the paper.

    A small fraction of a molecular cloud’s mass is made up by small dust grains that are mixed into the interstellar gas. These interstellar dust grains tend to align perpendicular to the direction of the magnetic field. As a result, the light emitted by the dust grains is polarized — and this polarization can be used to chart the magnetic field directions in molecular clouds.

    Recently, the Planck space mission produced a highly sensitive all–sky map of the polarized dust emission at wavelengths smaller than 1 mm. This provided the first large–scale view of the magnetization in filamentary molecular clouds and their environments. Studies done with Planck data found that filaments are not only highly magnetized, but they are coupled to the magnetic field in a predictable way. The orientation of the magnetic fields is parallel to the filaments in low–density environments. The magnetic fields change their orientation to being perpendicular to filaments at high gas densities, implying that magnetic fields play an important role relative in shaping filaments, compared to the influence of turbulence and gravity.

    This observation pointed towards a problem. In order to form stars in gaseous filaments, the filaments have to lose the magnetic fields. When and where does this happen? With the order of magnitude higher angular resolution of the HAWC+ instrument in comparison to Planck it was now possible to resolve the regions in filaments where the magnetic filament becomes less important.

    “Planck has revealed new aspects of magnetic fields in the interstellar medium, but the finer angular resolutions of SOFIA’s HAWC+ receiver and ground-based NIR polarimetry give us powerful new tools for revealing the vital details of the processes involved”, says Dan Clemens, Professor and Chair of the Boston University Astronomy Department, another co-author.

    “The fact that we were able to capture a critical transition in star formation was somewhat unexpected. This just shows how little is known about cosmic magnetic fields and how much exciting science awaits us from SOFIA with the HAWC+ receiver”, concludes Thushara Pillai.

    The research team comprises Thushara Pillai, Dan P. Clemens, Stefan Reissl, Philip C. Myers, Jens Kauffmann, Enrique Lopez-Rodriguez, Felipe de Oliveira Alves, Gabriel A. P. Franco, Jonathan Henshaw, Karl M. Menten, Fumitaka Nakamura, Daniel Seifried, Koji Sugitani, and Helmut Wiesemeyer. Thushara Pillai, the first author, and also Karl Menten and Helmut Wiesemeyer have an affiliation with the MPIfR.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition



    MPIFR/Effelsberg Radio Telescope, Germany

    The Max Planck Institute for Radio Astronomy (German: Max-Planck-Institut für Radioastronomie) is located in Bonn, Germany. It is one of 80 institutes in the

     
  • richardmitnick 7:03 am on July 21, 2020 Permalink | Reply
    Tags: "Pinning down the sun’s birthplace just got more complicated", , , , , Max Planck Institute for Radio Astronomy, New computer simulations of young stars suggest two pathways to forming the solar system., ,   

    From Max Planck Institute for Radio Astronomy via Science News: “Pinning down the sun’s birthplace just got more complicated” 


    From Max Planck Institute for Radio Astronomy

    via

    Science News

    July 20, 2020
    Lisa Grossman

    Our star’s birthplace might have been a tight, stellar cluster, researchers say.

    1
    Many astronomers think that a loose association of thousands of stars, like the cluster NGC 2244 in the Rosette Nebula shown here, is where the sun was born. A new study suggests there’s another possibility. Credit: NASA JPL-Caltech, U Arizona

    The sun could come from a large, loose-knit clan or a small family that’s always fighting.

    New computer simulations of young stars suggest two pathways to forming the solar system. The sun could have formed in a calm, large association of 10,000 stars or more, like NGC 2244 in the present-day Rosette Nebula, an idea that’s consistent with previous research. Or the sun could be from a violent, compact cluster with about 1,000 stars, like the Pleiades, researchers report July 2 in The Astrophysical Journal.

    Whether a star forms in a tight, rowdy cluster or a loose association can influence its future prospects. If a star is born surrounded by lots of massive siblings that explode as supernovas before a cluster spreads out, for example, that star will have more heavy elements to build planets with (SN: 8/9/19).

    To nail down a stellar birthplace, astronomers have considered the solar system’s chemistry, its shape and many other factors. Most astronomers who study the sun’s birthplace think the gentle, large association scenario is most likely, says astrophysicist Fred Adams of the University of Michigan in Ann Arbor, who was not involved in the new work.

    But most previous studies didn’t include stars’ motions over time. So astrophysicists Susanne Pfalzner and Kirsten Vincke, both of the Max Planck Institute for Radio Astronomy in Bonn, Germany, ran thousands of computer simulations to see how often different kinds of young stellar families produce solar systems like ours.

    The main solar system feature that the pair looked for was the distance to the farthest planet from the star. Planet-forming disks can extend to hundreds of astronomical units, or AU, the distance between the Earth and the sun (SN: 7/16/19). Theoretically, planets should be able to form all the way to the edge. But the sun’s planetary material is mostly packed within the orbit of Neptune.

    “You have a steep drop at 30 AU, where Neptune is,” Pfalzner says. “And this is not what you expect from a disk.”

    In 2018, Pfalzner and her colleagues showed that a passing star could have truncated and warped the solar system’s outer edge long ago [The Astrophysical Journal]. If that’s what happened, it could help point to the sun’s birth environment, Pfalzner reasoned. The key was to simulate groupings dense enough that stellar flybys happen regularly, but not so dense that the encounters happen too often and destroy disks before planets can grow up.

    “We were hoping we’d get one answer,” Pfalzner says. “It turned out there are two possibilities.” And they are wildly different from each other.

    Large associations have more stars, but the stars are more spread out and generally leave each other alone. Those associations can stay together for up to 100 million years. Compact clusters, on the other hand, see more violent encounters between young stars and don’t last as long. The stars shove each other away within a few million years.

    “This paper opens up another channel for what the sun’s birth environment looked like,” Adams says, referring to the violent cluster notion.

    The new study doesn’t cover every aspect of how a tight cluster could have affected the nascent solar system. The findings don’t account for how radiation from other stars in the cluster could erode planet-forming disks, for example, which could have shrunk the sun’s disk or even prevented the solar system from forming. The study also doesn’t explain certain heavy elements found in meteorites, which are thought to come from a nearby supernova and so could require the sun come from a long-lived stellar family.

    “I think [the research] is an interesting addition to the debate,” Adams says. “It remains to be seen how the pieces of the puzzle fit together.”

    Pfalzner thinks that the star cluster would break apart before radiation made a big difference, and there are other explanations for the heavy elements apart from a single supernova. She hopes future studies will be able to use that sort of cosmic chemistry to narrow the sun’s birthplace down even further.

    “For us humans, this is an important question,” Pfalzner says. “It’s part of our history.”

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition



    MPIFR/Effelsberg Radio Telescope, Germany

    The Max Planck Institute for Radio Astronomy (German: Max-Planck-Institut für Radioastronomie) is located in Bonn, Germany. It is one of 80 institutes in the Max Planck Society (German: Max-Planck-Gesellschaft).

    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 Max Planck Society for the Advancement of Science (German: Max-Planck-Gesellschaft zur Förderung der Wissenschaften e. V.; abbreviated MPG) 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, MIT, Stanford and the US NIH). In terms of total research volume (unweighted by citations or impact), the Max Planck Society is only outranked by the Chinese Academy of Sciences, the Russian Academy of Sciences 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 6:17 pm on January 22, 2020 Permalink | Reply
    Tags: "The riddle of the heavenly bursts", , , , , , Max Planck Institute for Radio Astronomy,   

    From Max Planck Institute for Radio Astronomy: “The riddle of the heavenly bursts” 


    From Max Planck Institute for Radio Astronomy

    January 20, 2020
    Dr. Laura Spitler
    Max Planck Institute for Radio Astronomy, Bonn
    +49 228 525-314
    lspitler@mpifr-bonn.mpg.de

    Dr. Norbert Junkes
    Press and public relations
    Max Planck Institute for Radio Astronomy, Bonn
    +49 2 28525-399
    njunkes@mpifr-bonn.mpg.de

    Time and again, radio telescopes register extremely short bursts of radiation in the depths of space.

    This cosmic lightning storm is happening all around us. Somewhere in the earthly sky, there is a pulse that flashes and extinguishes in the next moment. These bursts, which must be measured with radio telescopes and last one thousandth of a second, are one of the greatest mysteries of astrophysics. Scientists doubt that militant aliens are fighting “Star Wars” in the vastness of space. But where do these phenomena – dubbed “fast radio bursts” by the experts – come from?

    Text: Helmut Hornung

    2
    The radio telescope in Effelsberg is also part of the European VLBI network that searches for radio bursts. © MPI for Radio Astronomy / Norbert Tacken

    In the city of Parkes, gigantic lattice mesh bowl rises into the sky.

    CSIRO/Parkes Observatory, located 20 kilometres north of the town of Parkes, New South Wales, Australia, 414.80m above sea level

    In 2001, this 64-metre diameter radio telescope (once the largest fully mobile radio telescope in the southern hemisphere) registered a mysterious radio burst – and nobody noticed it! It wasn’t until five years later that astrophysicist Duncan Lorimer and his student David Narkevic found the signature of the signal in the telescope data more or less by chance. Even then, the specialists could not make sense of the phenomenon. But this was not the only “Lorimer burst”.

    “We now know of more than a hundred”, says Laura Spitler. Since March 2019, the researcher has headed a Lise Meitner group on this topic at the Max Planck Institute for Radio Astronomy. Spitler has dedicated herself to these fleeting flickers in space for many years. Under her leadership, an international team discovered the first fast radio burst (FRB) on the northern celestial sphere in the Fuhrmann constellation in 2014. Astronomers had used the dish of the Arecibo telescope on Puerto Rico.


    NAIC Arecibo Observatory operated by University of Central Florida, Yang Enterprises and UMET, Altitude 497 m (1,631 ft).

    The antenna, which measures 305 m in diameter, is firmly anchored in a natural valley and can only ever focus on a relatively small section of the firmament.

    “Statistically speaking, there should be only seven eruptions per minute spread across the sky. It therefore takes a lot of luck to align your telescope to the right position at the right time”, said Spitler after the discovery was announced. Both the properties of the radio bursts and their frequency derived from the measurements were in high agreement with what astronomers had found out about all the previously observed eruptions.

    In fact, statistical assumptions were confirmed; according to these, approx. 10,000 of these unusual cosmic phenomena were thought to flare up in the earthly firmament each day. The surprisingly large number results from calculations of how much of the sky would have to be observed and for how long in order to explain the comparatively few discoveries made so far.

    The Arecibo measurement also removed the last doubts about whether the radio bursts really came from the depths of the universe. After the first registered bursts, scientists concluded that they were being generated in an area far outside the Milky Way. This was deduced from an effect called plasma dispersion. When radio signals travel a long distance through the universe, they encounter numerous free electrons located in the space between the stars.

    Ultimately, the speed of propagation of radio waves at lower frequencies decreases in a characteristic manner. For example, during the aforementioned radiation burst discovered with the Arecibo telescope, this dispersion was three times larger than one would expect from a source within the Milky Way. If the source were located in the galaxy, interstellar matter would contribute roughly 33% for the Arecibo source.


    A repeating Fast Radio Burst from a spiral galaxy
    Scientists on the trail of radio flashes – an explanatory video in English

    But what is the origin of the radio bursts? The astrophysicists have designed various scenarios, all more or less exotic. Many of them revolve around neutron stars. These are the remnants of massive explosions of massive suns as supernovae, only 30 km in size. In these spheres, matter is so densely packed that on Earth, one teaspoonful of its matter would weigh about as much as the Zugspitze massif. The neutron stars rotate quickly around their axes. Some of them have exceptionally strong magnetic fields.

    For example, fast radio bursts could occur during a supernova – but also during the fusion of two neutron stars in a close binary star system – when the magnetic fields of the two individual stars collapse. In addition, a neutron star could collapse further into a black hole, emitting a burst.

    These scientific scripts sound plausible at first glance. However, they have one flaw: They predict only one radio burst at a time. “If the flash was generated in a cataclysmic event that destroys the source, only one burst per source can be expected”, says Laura Spitler. Indeed, in the early years, there were always single outbreaks – until in 2014 a burst called FRB 121102 went online. In 2016, Spitler and her team observed this to be the first “repeater”, a burst with repeating pulses. “This refuted all models that explain FRB as the consequence of a catastrophic event”, says Spitler.

    The FRB 121102, discovered at the Arecibo telescope, was further observed by the researchers with the Very Large Array in New Mexico.

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

    After 80 hours of measuring time, they registered nine bursts and determined the position with an accuracy of one arc second. At this position in the sky, there is a permanently radiating radio source; optical images show a faint galaxy about three billion light years away.

    With a diameter of only 13,000 light years, this star system is one of the dwarfs; the Milky Way is about ten times larger. “However, many new stars and perhaps even particularly large ones are born in this galaxy. This could be an indication of the source of the radio bursts”, says Spitler.

    The researcher thinks of pulsars – cosmic lighthouses that regularly emit radio radiation.

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

    Behind them are again fast rotating neutron stars with strong magnetic fields. If the axis of rotation and the axis of the magnetic field of such an object deviate from each other, a bundled radio beam can be produced. Each time this natural spotlight sweeps across the Earth, astronomers measure a short pulse.

    The bursts of most radio pulsars are too weak for them to be detected from a great distance. This is not the case with the particularly short and extremely strong “giant pulses”. A prime example of this class of objects is the crab pulsar, which was born in a supernova explosion observed in 1054 AD.

    Supernova remnant Crab nebula. NASA/ESA Hubble

    X-ray picture of Crab pulsar, taken by Chandra

    Its pulses would be visible even from neighbouring galaxies.

    “A promising model suggests that fast radio bursts are much stronger and rarer than giant pulses from extragalactic neutron stars similar to the crab pulsar. Or even younger and more energetic ones like this one”, says Spitler. “The home galaxy of FRB 121102 fits this model because it has the potential to produce just the right stars to become neutron stars at the end of their lives”.

    But whether this model is correct is literally written in the stars. The clarification is not getting any easier. Nevertheless, the observations continue. For example, the radio antennas of the European VLBI network examined another repeater in summer 2019.

    European VLBI

    FRB 180916.J0158+65 showed no less than four radiation outbursts during the five-hour observation. Each lasted less than two milliseconds.

    The home of this radio burst is in a spiral galaxy about 500 million light-years away. This makes it the closest observed so far even though this distance seems “astronomical”. It also turns out that there is apparently a high rate of star births around the burst.

    The position in the galaxy differs from that of all other bursts investigated so far. In other words: Apparently, the FRB flare up in all kinds of cosmic regions and diverse environments. “This is one of the reasons why it is still unclear whether all bursts have the same source type or are generated by the same physical processes”, says Spitler. “The mystery of their origin remains”.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition



    MPIFR/Effelsberg Radio Telescope, Germany

    The Max Planck Institute for Radio Astronomy (German: Max-Planck-Institut für Radioastronomie) is located in Bonn, Germany. It is one of 80 institutes in the Max Planck Society (German: Max-Planck-Gesellschaft).

    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 Max Planck Society for the Advancement of Science (German: Max-Planck-Gesellschaft zur Förderung der Wissenschaften e. V.; abbreviated MPG) 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, MIT, Stanford and the US NIH). In terms of total research volume (unweighted by citations or impact), the Max Planck Society is only outranked by the Chinese Academy of Sciences, the Russian Academy of Sciences 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 3:37 pm on December 31, 2019 Permalink | Reply
    Tags: "Giant magnetic ropes in the outskirts of a spiral galaxy", A regular magnetic field over scales of several thousands of light years in the halo of NGC 4631, , , , , Max Planck Institute for Radio Astronomy, , The spiral galaxy NGC 463 the “Whale Galaxy”, They discovered reversals in the large-scale magnetic field which they call giant magnetic ropes.   

    From Max Planck Institute for Radio Astronomy: “Giant magnetic ropes in the outskirts of a spiral galaxy” 


    From Max Planck Institute for Radio Astronomy

    November 26, 2019
    Max-Planck-Institut für Radioastronomie, Bonn
    Dr. Marita Krause
    Phone:+49 228 525-312
    mkrause@mpifr-bonn.mpg.de

    Max-Planck-Institut für Radioastronomie, Bonn
    Dr. Norbert Junkes
    Press and Public Outreach
    Phone:+49 228 525-399
    Email:
    njunkes@mpifr-bonn.mpg.de

    1
    The spiral galaxy NGC 4631 is seen edge-on, with its disk of stars shown in pink. The observed magnetic field pattern is displayed by the hair-like structure in green and blue. It extends beyond the disk into the galaxy’s extended halo. Green indicates magnetic fields pointing roughly toward us and blue fields pointing away from us. This phenomenon, with the field alternating in direction, has never before been seen in the halo of a galaxy.
    © Composite image by Jayanne English (Univ. of Manitoba). Radio data: Jansky-VLA (Silvia Carolina Mora-Partiarroyo et al. 2019). Optical data: Mayall 4-meter telescope (Maria Patterson and Rene Walterbos, New Mexico State Univ.). Software code for tracing the magnetic field lines: Arpad Miskolczi (Ruhr-Univ. Bochum).

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


    NOAO/Mayall 4 m telescope at Kitt Peak, Arizona, USA, Altitude 2,120 m (6,960 ft)

    First detection of regular magnetic field reversals in the halo of NGC 4631

    An international consortium led by scientists from the Max Planck Institute for Radio Astronomy in Bonn, Germany, investigated polarized radio emission from the galaxy NGC 4631 at the VLA radio telescope with a broad-band receiver in a number of spectral windows. They detected for the first time a regular magnetic field over scales of several thousands of light years in the halo of NGC 4631. Moreover, they discovered reversals in the large-scale magnetic field, which they call giant magnetic ropes. This discovery will strengthen the impact of large-scale dynamo theories for spiral galaxies. Further, the regular halo fields may be regarded as a link to intergalactic magnetic fields and will help to understand their origin which is a mystery so far.

    The results are reported in the current issue of the journal Astronomy & Astrophysics.

    NGC 4631, the “Whale Galaxy”, located 25 million light-years from Earth in the constellation Canes Venatici, is about 80 thousand light-years across, slightly smaller than our own Milky Way. It was discovered by the famous German-born British astronomer Sir William Herschel in 1787. This galaxy has a companion, NGC 4627, a small elliptical galaxy.

    Observations of the polarized radio emission of NGC 4631, performed with the Karl G. Jansky Very Large Array (VLA), reveal regular magnetic fields protruding above and below the galaxy’s disk (see Fig. 1).

    “This is the first time that we have clearly detected what astronomers call large-scale, coherent, magnetic fields far in the halo of a spiral galaxy, with the field lines aligned in the same direction over distances of a thousand light-years. We even see a regular pattern of this organized field changing direction,” said Marita Krause, scientist at the Max-Planck Institute for Radioastronomy (MPIfR) in Bonn, Germany, and corresponding author of the publication.

    The strength of 4 microGauss for the regular magnetic field is surprisingly high for a halo, comparable with the regular magnetic field strength in the disks of spiral galaxies.

    An international team of astronomers who are part of a project called the Continuum HAlos in Nearby Galaxies — an EVLA Survey (CHANG-ES), said the image indicates a large-scale, coherent magnetic field that is generated by dynamo action within the galaxy and spirals far outward in the form of giant magnetic ropes perpendicular to the disk. The CHANG-ES project is led by Judith Irwin of Queen’s University in Ontario, Canada, a co-author of the paper.

    “At the moment, I’m afraid that we are a little bit like the blind men and the elephant, since each time we sample the magnetic field in a different way we reach a different conclusion about its nature! However, our models suggest this field includes smaller, twisting cones emanating from the spiral arms,” said Richard Henriksen, also of Queen’s University.

    The results were achieved by combining data from multiple observations with the VLA’s giant dish antennas arranged in different configurations to show both large structures and finer details within NGC 4631. The naturally-emitted radio waves from that galaxy were analyzed to reveal the magnetic fields, including their directions.

    The scientists said the techniques used to determine the direction of the magnetic field lines can now be used on other galaxies to answer important questions about whether coherent magnetic fields are common in galactic halos and what their shapes are.

    The regular halo fields may also be regarded as a link to intergalactic magnetic fields and will help to understand their origin which is a mystery up to now.

    ——————————————

    CHANG-ES, the “Continuum Halos in Nearby Galaxies, an EVLA Survey” project, brings together scientists from all over the globe in order to investigate the occurrence and origin of galaxy halos by means of radio observations.

    The extended spherical area around the disk of a spiral galaxy is called halo. It forms the interface between the well-studied disks of galaxies and the intergalactic medium.

    The National Radio Astronomy Observatory (NRAO) is a facility of the National Science Foundation (NSF), operated under cooperative agreement by Associated Universities, Inc. The Karl G. Jansky Very Large Array (VLA) interferometer near Socorro (New Mexico, USA) is operated by NRAO.

    Authors of the original paper comprise Silvia Carolina Mora-Partiarroyo, Marita Krause, Aritra Basu, Rainer Beck, Theresa Wiegert, Judith Irwin, Richard Henriksen, Yelena Stein, Carlos J. Vargas, Volker Heesen, René A. M. Walterbos, Richard J. Rand, George Heald, Jiangtao Li, Patrick Kamieneski, and Jayanne English. The first four authors are all affiliated with the MPIfR in Bonn, Germany.

    The results are based on the doctoral thesis of Silvia Carolina Mora-Partiarroyo, the first author, at MPIfR and Bonn University. The thesis was supervised by Marita Krause.

    A theoretical model is described in Woodfinden et al. 2019 MNRAS, 487, 1498.

    See the full article here. .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition



    MPIFR/Effelsberg Radio Telescope, Germany

    The Max Planck Institute for Radio Astronomy (German: Max-Planck-Institut für Radioastronomie) is located in Bonn, Germany. It is one of 80 institutes in the Max Planck Society (German: Max-Planck-Gesellschaft).

    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 Max Planck Society for the Advancement of Science (German: Max-Planck-Gesellschaft zur Förderung der Wissenschaften e. V.; abbreviated MPG) 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, MIT, Stanford and the US NIH). In terms of total research volume (unweighted by citations or impact), the Max Planck Society is only outranked by the Chinese Academy of Sciences, the Russian Academy of Sciences 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 7:43 pm on November 26, 2019 Permalink | Reply
    Tags: , , , , Max Planck Institute for Radio Astronomy, NGC 4631,   

    From Max Planck Institute for Radio Astronomy: “Giant magnetic ropes in the outskirts of a spiral galaxy” 


    From Max Planck Institute for Radio Astronomy

    November 26, 2019

    Dr. Marita Krause
    Phone:+49 228 525-312
    mkrause@mpifr-bonn.mpg.de

    Max-Planck-Institut für Radioastronomie, Bonn
    Dr. Norbert Junkes
    Press and Public Outreach
    Phone:+49 228 525-399
    njunkes@mpifr-bonn.mpg.de

    First detection of regular magnetic field reversals in the halo of NGC 4631.

    An international consortium led by scientists from the Max Planck Institute for Radio Astronomy in Bonn, Germany, investigated polarized radio emission from the galaxy NGC 4631 at the VLA radio telescope with a broad-band receiver in a number of spectral windows.

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

    They detected for the first time a regular magnetic field over scales of several thousands of light years in the halo of NGC 4631. Moreover, they discovered reversals in the large-scale magnetic field, which they call giant magnetic ropes. This discovery will strengthen the impact of large-scale dynamo theories for spiral galaxies. Further, the regular halo fields may be regarded as a link to intergalactic magnetic fields and will help to understand their origin which is a mystery so far.

    The results are reported in the current issue of the journal Astronomy & Astrophysics.

    1
    The spiral galaxy NGC 4631 is seen edge-on, with its disk of stars shown in pink. The observed magnetic field pattern is displayed by the hair-like structure in green and blue. It extends beyond the disk into the galaxy’s extended halo. Green indicates magnetic fields pointing roughly toward us and blue fields pointing away from us. This phenomenon, with the field alternating in direction, has never before been seen in the halo of a galaxy.

    © Composite image by Jayanne English (Univ. of Manitoba). Radio data: Jansky-VLA (Silvia Carolina Mora-Partiarroyo et al. 2019). Optical data: Mayall 4-meter telescope (Maria Patterson and Rene Walterbos, New Mexico State Univ.). Software code for tracing the magnetic field lines: Arpad Miskolczi (Ruhr-Univ. Bochum).


    NOAO/Mayall 4 m telescope at Kitt Peak, Arizona, USA, Altitude 2,120 m (6,960 ft)

    NGC 4631, the “Whale Galaxy”, located 25 million light-years from Earth in the constellation Canes Venatici, is about 80 thousand light-years across, slightly smaller than our own Milky Way. It was discovered by the famous German-born British astronomer Sir William Herschel in 1787. This galaxy has a companion, NGC 4627, a small elliptical galaxy.

    Observations of the polarized radio emission of NGC 4631, performed with the Karl G. Jansky Very Large Array (VLA), reveal regular magnetic fields protruding above and below the galaxy’s disk (see Fig. 1).

    “This is the first time that we have clearly detected what astronomers call large-scale, coherent, magnetic fields far in the halo of a spiral galaxy, with the field lines aligned in the same direction over distances of a thousand light-years. We even see a regular pattern of this organized field changing direction,” said Marita Krause, scientist at the Max-Planck Institute for Radioastronomy (MPIfR) in Bonn, Germany, and corresponding author of the publication.

    The strength of 4 microGauss for the regular magnetic field is surprisingly high for a halo, comparable with the regular magnetic field strength in the disks of spiral galaxies.

    An international team of astronomers who are part of a project called the Continuum HAlos in Nearby Galaxies — an EVLA Survey (CHANG-ES), said the image indicates a large-scale, coherent magnetic field that is generated by dynamo action within the galaxy and spirals far outward in the form of giant magnetic ropes perpendicular to the disk. The CHANG-ES project is led by Judith Irwin of Queen’s University in Ontario, Canada, a co-author of the paper.

    “At the moment, I’m afraid that we are a little bit like the blind men and the elephant, since each time we sample the magnetic field in a different way we reach a different conclusion about its nature! However, our models suggest this field includes smaller, twisting cones emanating from the spiral arms,” said Richard Henriksen, also of Queen’s University.

    The results were achieved by combining data from multiple observations with the VLA’s giant dish antennas arranged in different configurations to show both large structures and finer details within NGC 4631. The naturally-emitted radio waves from that galaxy were analyzed to reveal the magnetic fields, including their directions.

    The scientists said the techniques used to determine the direction of the magnetic field lines can now be used on other galaxies to answer important questions about whether coherent magnetic fields are common in galactic halos and what their shapes are.

    The regular halo fields may also be regarded as a link to intergalactic magnetic fields and will help to understand their origin which is a mystery up to now.

    CHANG-ES, the “Continuum Halos in Nearby Galaxies, an EVLA Survey” project, brings together scientists from all over the globe in order to investigate the occurrence and origin of galaxy halos by means of radio observations.

    The extended spherical area around the disk of a spiral galaxy is called halo. It forms the interface between the well-studied disks of galaxies and the intergalactic medium.

    The National Radio Astronomy Observatory (NRAO) is a facility of the National Science Foundation (NSF), operated under cooperative agreement by Associated Universities, Inc. The Karl G. Jansky Very Large Array (VLA) interferometer near Socorro (New Mexico, USA) is operated by NRAO.

    Authors of the original paper comprise Silvia Carolina Mora-Partiarroyo, Marita Krause, Aritra Basu, Rainer Beck, Theresa Wiegert, Judith Irwin, Richard Henriksen, Yelena Stein, Carlos J. Vargas, Volker Heesen, René A. M. Walterbos, Richard J. Rand, George Heald, Jiangtao Li, Patrick Kamieneski, and Jayanne English. The first four authors are all affiliated with the MPIfR in Bonn, Germany.

    The results are based on the doctoral thesis of Silvia Carolina Mora-Partiarroyo, the first author, at MPIfR and Bonn University. The thesis was supervised by Marita Krause.

    A theoretical model is described in Woodfinden et al. 2019 MNRAS, 487, 1498.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition



    MPIFR/Effelsberg Radio Telescope, Germany

    The Max Planck Institute for Radio Astronomy (German: Max-Planck-Institut für Radioastronomie) is located in Bonn, Germany. It is one of 80 institutes in the Max Planck Society (German: Max-Planck-Gesellschaft).

    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 Max Planck Society for the Advancement of Science (German: Max-Planck-Gesellschaft zur Förderung der Wissenschaften e. V.; abbreviated MPG) 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, MIT, Stanford and the US NIH). In terms of total research volume (unweighted by citations or impact), the Max Planck Society is only outranked by the Chinese Academy of Sciences, the Russian Academy of Sciences 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 2:46 pm on October 2, 2019 Permalink | Reply
    Tags: , Max Planck Institute for Radio Astronomy, The neutrino event IceCube 170922A and the distant BL Lac object active galaxy TXS 0506+056, This was the first neutrino from outer space whose origin could be confirmed.,   

    From Max Planck Institute for Radio Astronomy: “Neutrino produced in a cosmic collider far away” 


    From Max Planck Institute for Radio Astronomy

    October 02, 2019

    Priv.-Doz. Dr. Silke Britzen
    Phone:+49 228 525-280
    sbritzen@mpifr-bonn.mpg.de
    Max Planck Institute for Radio Astronomy,Bonn

    Prof. Dr. Christian Fendt
    Phone:+49 6221 528-387
    fendt@mpia-hd.mpg.de.
    Max Planck Institute for Radio Astronomy,Heidelberg

    Max-Planck-Institut für Astronomie,
    Dr. Norbert Junkes
    Press and Public Outreach
    Phone:+49 228 525-399
    njunkes@mpifr-bonn.mpg.de
    Max Planck Institute for Radio Astronomy,Bonn

    Link between IceCube neutrino event and distant radio galaxy resolved

    The neutrino event IceCube 170922A, detected at the IceCube Neutrino Observatory at the South Pole, appears to originate from the distant active galaxy TXS 0506+056, at a light travel distance of 3.8 billion light years. TXS 0506+056 is one of many active galaxies and it remained a mystery, why and how only this particular galaxy generated neutrinos so far.

    An international team of researchers led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, studied high-resolution radio observations of the source between 2009 and 2018, before and after the neutrino event. The team proposes that the enhanced neutrino activity during an earlier neutrino flare and the single neutrino could have been generated by a cosmic collision within TXS 0506+056. The clash of jet material close to a supermassive black hole seems to have produced the neutrinos.

    The results are published in Astronomy & Astrophysics, October 02, 2019.

    1
    TXS 0506+056. The neutrino event IceCube 170922A appears to originate in the interaction zone of the two jets.
    © IceCube Collaboration, MOJAVE, S. Britzen, & M. Zajaček

    On July 12, 2018, the IceCube collaboration announced the detection of the first high-energy neutrino, IceCube-170922A, which could be traced back to a distant cosmic origin. While the cosmic origin of neutrinos had been suspected for quite some time, this was the first neutrino from outer space whose origin could be confirmed. The “home” of this neutrino is an Active Galactic Nucleus (AGN) – a galaxy with a supermassive black hole as central engine. An international team could now clarify the production mechanism of the neutrino and found an equivalent to a collider on Earth: a cosmic collision of jetted material.

    AGN are the most energetic objects in our Universe. Powered by a supermassive black hole, matter is being accreted and streams of plasma (so-called jets) are launched into intergalactic space. BL Lac objects form a special class of these AGN, where the jet is directly pointing at us and dominating the observed radiation. The neutrino event IceCube-170922A appears to originate from the BL Lac object TXS 0506+056, a galaxy at a redshift of z=0.34, corresponding to a light travel distance of 3.8 billion light years. An analysis of archival IceCube data by the IceCube Collaboration had revealed evidence of an enhanced neutrino acitvity earlier, between September 2014 and March 2015.

    Other BL Lac Objects show properties quite similar to those of TXS 0506+056. „It was a bit of a mystery, however, why only TXS 0506+056 has been identified as neutrino emitter“, explains Silke Britzen from the Max Planck Institute for Radio Astronomy (MPIfR), the lead author of the paper. „We wanted to unravel what makes TXS 0506+056 special, to understand the neutrino creation process and to localize the emission site and studied a series of high resolution radio images of the jet.“

    Much to their surprise, the researchers found an unexpected interaction between jet material in TXS 0506+056. While jet plasma is usually assumed to flow undisturbed in a kind of channel, the situation seems different in TXS 0506+056. The team proposes that the enhanced neutrino activity during the neutrino flare in 2014–2015 and the single EHE neutrino
    IceCube-170922A could have been generated by a cosmic collision within the source.

    This cosmic collision can be explained by new jet material clashing into older jet material. A strongly curved jet structure provides the proper set up for such a scenario. Another explanation involves the collision of two jets in the same source. In both scenarios, it is the collision of jetted material which generates the neutrino. Markus Böttcher from the North-West University in Potchefstroom (South Africa), a co-author of the paper, performed the calculations with regard to the radiation and particle emission. „This collision of jetted material is currently the only viable mechanism which can explain the neutrino detection from this source. It also provides us with important insight into the jet material and solves a long-standing question whether jets are leptonic, consisting of electrons and positrons, or hadronic, consisting of electrons and protons, or a combination of both. At least part of the jet material has to be hadronic – otherwise, we would not have detected the neutrino.“

    In the course of the cosmic evolution of our Universe, collisions of galaxies seem to be a frequent phenomenon. Assuming that both galaxies contain central supermassive black holes, the galactic collision can result in a black hole pair at the centre. This black hole pair might eventually merge and produce the supermassive equivalent to stellar black hole mergers as detected in gravitational waves by the LIGO/Virgo collaboration.

    AGN with double black holes at a small separation of only light years have been pursued for many years. However, they seem to be rare and difficult to identify. In addition to the collision of jetted material, the team also found evidence for a precession of the central jet of TXS 0506+056. According to Michal Zajaček from the Center for Theoretical Physics, Warsaw: „This precession can in general be explained by the presence of a supermassive black hole binary or the Lense-Thirring precession effect as predicted by Einstein’s theory of general relativity. The latter could also be triggered by a second, more distant black hole in the centre. Both scenarios lead to a wandering of the jet direction, which we observe.“

    Christian Fendt from the Max Planck Institute for Astronomy in Heidelberg is amazed: „The closer we look at the jet sources the more complicated the internal structure and jet dynamics appears. While binary black holes produce a more complex outflow structure, their existence is naturally expected from the cosmological models of galaxy formation by galaxy mergers.”

    Silke Britzen stresses the scientific potential of the findings: „It’s fantastic to understand the neutrino generation by studying the insides of jets. And it would be a breakthrough if our analysis had provided another candidate for a binary black hole jet source with two jets.“

    It seems to be the first time that a potential collision of two jets on scales of a few light years has been reported and that the detection of a cosmic neutrino might be traced back to a cosmic jet-collision.

    While TXS 0506+056 might not be representative of the class of BL Lac objects, this source could provide the proper setup for a repeated interaction of jetted material and the generation of neutrinos.

    ——————————-
    Background Information:

    U Wisconsin ICECUBE neutrino detector at the South Pole

    The IceCube Neutrino Observatory is designed to observe the cosmos from deep within the South Pole ice.

    IceCube is a particle detector at the South Pole that records the interactions of a nearly massless sub-atomic particle called the neutrino. IceCube searches for neutrinos from the most violent astrophysical sources: events like exploding stars, gamma ray bursts, and cataclysmic phenomena involving black holes and neutron stars. The IceCube telescope is a powerful tool to search for dark matter, and could reveal the new physical processes associated with the enigmatic origin of the highest energy particles in nature. In addition, exploring the background of neutrinos produced in the atmosphere, IceCube studies the neutrinos themselves; their energies far exceed those produced by accelerator beams. IceCube is the world’s largest neutrino detector, encompassing a cubic kilometer of ice.

    IceCube employs more than 5000 detectors lowered on 86 strings into almost 100 holes in the Antarctic ice NSF B. Gudbjartsson, IceCube Collaboration

    Lunar Icecube

    IceCube DeepCore annotated

    IceCube PINGU annotated


    DM-Ice II at IceCube annotated

    Encompassing a cubic kilometer of ice, IceCube searches for nearly massless subatomic particles called neutrinos. These high-energy astronomical messengers provide information to probe the most violent astrophysical sources: events like exploding stars, gamma-ray bursts, and cataclysmic phenomena involving black holes and neutron stars.

    MOJAVE (Monitoring Of Jets in Active galactic nuclei with VLBA Experiments) is a long-term program to monitor radio brightness and polarization variations in jets associated with active galaxies visible in the northern sky. The Very Long Baseline Array (VLBA) is a system of ten radio telescopes which are operated from Socorro, New Mexico. The ten radio antennas work together as an array using very long baseline interferometry.

    NRAO/VLBA

    A BL Lac Object is a special subclass of an Active Galactic Nucleus (AGN). An AGN is a compact region at the center of a galaxy that has a much higher than normal luminosity over at least some portion of the electromagnetic spectrum. This luminosity is non-thermal and produced by accretion of matter close to a central black hole. The jet of a BL Lac Object is directed at the observer giving a unique radio emission spectrum.

    Authors of the original paper in “Astronomy & Astrophysics” are Silke Britzen, Christian Fendt, Markus Böttcher, Michal Zajaček, Frederic Jaron, Ilya Pashchenko, Anabella Araudo, Vladimir Karas, and Omar Kurtanidze. Silke Britzen, the first author, and also Michal Zajaček and Frederic Jaron are affiliated to the MPIfR.

    Besides MPIfR, affiliations of the authors include the Max-Planck-Institut für Astronomie (Heidelberg, Germany), the Centre for Space Research (North-West University, Potchefstroom, South Africa), the I. Physikalisches Institut, (Universität Köln, Germany), the Center for Theoretical Physics, (Polish Academy of Sciences, Warsaw, Poland), the Institute of Geodesy and Geoinformation (University of Bonn, Germany), the Astro Space Center, (Lebedev Physical Institute, Russian Academy of Sciences, Russia), the Astronomical Institute and the Institute of Physics (Czech Academy of Sciences, Prague, Czech Republic) and the Abastumani Observatory in Georgia.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition



    MPIFR/Effelsberg Radio Telescope, Germany

    The Max Planck Institute for Radio Astronomy (German: Max-Planck-Institut für Radioastronomie) is located in Bonn, Germany. It is one of 80 institutes in the Max Planck Society (German: Max-Planck-Gesellschaft).

    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 Max Planck Society for the Advancement of Science (German: Max-Planck-Gesellschaft zur Förderung der Wissenschaften e. V.; abbreviated MPG) 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, MIT, Stanford and the US NIH). In terms of total research volume (unweighted by citations or impact), the Max Planck Society is only outranked by the Chinese Academy of Sciences, the Russian Academy of Sciences 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 1:45 pm on June 25, 2018 Permalink | Reply
    Tags: , , , , , Galaxy OJ 287, , Max Planck Institute for Radio Astronomy, , , Super-mass-rich black hole   

    From MPG: “Close-up of a galaxy nucleus” 

    MPG bloc

    From Max Planck Gesellschaft

    June 25, 2018

    Dr. Norbert Junkes
    Press and public relations
    Max Planck Institute for Radio Astronomy, Bonn
    +49 2 28525-399
    njunkes@mpifr-bonn.mpg.de

    Dr. Silke Britzen
    Max Planck Institute for Radio Astronomy, Bonn
    +49 228 525-280 sbritzen
    @mpifr-bonn.mpg.de

    Dr. Christian Fendt
    Max Planck Institute for Astronomy, Heidelberg
    +49 6221 528-387
    fendt@mpia-hd.mpg.de

    Max Planck Institute for Radio Astronomy Bonn Germany

    Max Planck Institute for Astronomy campus Heidelberg, Baden-Württemberg, Germany

    In the centre of the galaxy OJ 287, there is one active, super-mass-rich black hole. An international research team led by Silke Britzen of the Max Planck Institute for Radio Astronomy has now discovered that the active nucleus of this galaxy generates a jet that staggers like a spinning top on a time jet on a timescale of about 22 years. With this movement called ‘precession’, the fluctuation of the radiation of OJ 287 can be explained. The discovery thus provides the key to understanding the variability in active galaxy nuclei.

    1
    Zoom into the heart of a galaxy: artist’s impression of the central region of the active galaxy OJ 287 with a preceding jet. The precession could either be caused by a binary black hole (Inset A) or by a mis-aligned accretion disk (Inset B).
    © Axel Quetz / MPIA Heidelberg

    It took a long time to decipher the Egyptian hieroglyphs, the inscriptions of the pyramids. It finally succeeded with the help of the so-called Rosetta Stone found in 1799. This stele was inscribed with three versions of the same text – one in Ancient Egyptian using hieroglyphic script, one in Demotic script, and the bottom one in Ancient Greek. Realizing that it is the same text, the enigmatic hieroglyphs could be deciphered and translated with the help of the ancient Greek language. This discovery opened up a whole new window to understand the ancient Egyptian culture. A research team now has deciphered the jet of a galaxy which has been named the Rosetta Stone of blazars. Blazars are active galactic nuclei where a central supermassive black hole is being fed.

    The well-known galaxy OJ 287 at a distance of about 3.5 billion light years harbors at least one supermassive black hole weighing Millions to Billions of solar masses. The supermassive black hole is active and produces a jet – a plasma stream which originates in the central nuclear region of galaxies in the vicinity of the central black hole. This jet is observable at radio wavelengths. The galaxy is also a well-known target to optical astronomers. The brightness fluctuations of this galaxy in the optical regime are legendary and have been observed since the late 19th century, providing one of the longest light-curves in astronomy.

    However, despite decades of radio observations of many jet sources and many sophisticated studies, jets remained enigmatic. Traditionally, the origin of the jet brightness variations observed at radio wavelengths was attributed to the jet feeding mechanism by the central black hole system. On the other hand, the observed moving features in the jets – called knots – were attributed to shocks traveling in the jet. Researchers looked for a connection between both phenomena but this could not be done consistently so far.

    The research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy (MPIfR) in Bonn used a clever observational technique to monitor the jet of OJ 287 close to its launching site near the central black hole in precious detail. The technique of radio interferometry involves radio telescopes around the globe in order to construct a virtual monster telescope of earth size diameter that is able to zoom into the very centers of galaxies and to observe jets close to the central black hole with unprecedented resolution.

    By considering a large data set spanning a long period of time, the team has now found strong indication that both phenomena have the same origin: both types of observations can be explained by the motion of the jet only. The jet itself is precessing. Michal Zajacek, also from the MPIfR, who has done the modeling of the precession model: “The brightness variations result from the jet precession that induces a variation of the Doppler boosting when the viewing angle of the jet changes. It was really surprising when we found that not only does the jet precess, it also seems to follow a smaller nutation-like motion. The combined precession-nutation motion leads to the radio variability and can also explain some of the light flares.“

    “We realized that it is the same physical process that explains both the jet wandering in the sky and the brightness variations of the galaxy – that is the change of motion of the jet. It’s all geometry and deterministic. No magic involved, so far”, adds Silke Britzen. “This offers a unique opportunity to understand the jets and their potential origin in the immediate vicinity of the black hole. This jet really serves as Rosetta stone for us and will allow to understand jets and their active black holes much more fundamentally.”Britzen and her team are convinced that the precession-scenario can also explain the 130 years of optical flaring of this source but, as always, more data and more work is required for a final confirmation.

    A pressing question remains about the origin of the jet precession. Precession is a physical process well-known from spinning tops or the Earth itself. The rotational axis of our planet is not stable but orbiting in space with a period of 26,000 years due to the tidal influence of the Sun and the moon. For the jet precession in OJ 287 the team has indicated two possible scenarios. “We either have a system of two supermassive black holes with the disk-ejecting jet forced to wobble by tidal effects of the secondary black hole or a single black hole that is tidaly interacting with a misaligned accretion disk,” concludes Christian Fendt from the Max Planck Institute for Astronomy (MPIA) in Heidelberg.Either way, the jet of the active galaxy OJ 287 is one of the best understood jets so far and will certainly be used to decipher other extragalactic jets as well. It might even help to further unravel the enigmatic activity of supermassive black holes.

    Science papers:
    OJ287: Deciphering the “Rosetta stone of blazars”, MNRAS
    Jet precession in binary black holes Nature

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    MPG campus

    The Max Planck Society for the Advancement of Science (German: Max-Planck-Gesellschaft zur Förderung der Wissenschaften e. V.; abbreviated MPG) 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, MIT, Stanford and the US NIH). In terms of total research volume (unweighted by citations or impact), the Max Planck Society is only outranked by the Chinese Academy of Sciences, the Russian Academy of Sciences 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 3:51 pm on October 12, 2017 Permalink | Reply
    Tags: , , , , , Max Planck Institute for Radio Astronomy, , The far side of the Milky Way   

    From Max Planck Institute for Radio Astronomy and CfA : “The far side of the Milky Way” 


    Max Planck Institute for Radio Astronomy

    CfA

    October 12, 2017
    Contact
    Dr. Alberto Sanna
    Max Planck Institute for Radio Astronomy, Bonn
    Phone:+49 228 525-304
    asanna@mpifr-bonn.mpg.de

    Prof. Dr. Karl M. Menten
    Max Planck Institute for Radio Astronomy, Bonn
    Phone:+49 228 525-297
    Fax:+49 228 525-435
    kmenten@mpifr-bonn.mpg.de

    Dr. Norbert Junkes
    Max Planck Institute for Radio Astronomy, Bonn
    Phone:+49 228 525-399
    njunkes@mpifr.de

    Astronomers achieve record measurement for an improved picture of our home galaxy.

    Astronomers from the Max Planck Institute for Radio Astronomy in Bonn, Germany, and the Harvard-Smithsonian Center for Astrophysics, using the Very Long Baseline Array, have directly measured a distance of more than 66,000 light-years to a star-forming region. This region, known as G007.47+00.05, is on the opposite side of our Milky Way Galaxy from the Sun. The researchers’ achievement reaches deep into the Milky Way’s terra incognita and nearly doubles the previous record for distance measurement within our Galaxy.

    NRAO VLBA


    NRAO/VLBA


    Milky Way NASA/JPL-Caltech /ESO R. Hurt

    Distance measurements are crucial for an understanding of the structure of the Milky Way. Most of our Galaxy’s material, consisting principally of stars, gas, and dust, lies within a flattened disk, in which our Solar System is embedded. Because we cannot see our Galaxy face-on, its structure, including the shape of its spiral arms, can only be mapped by measuring distances to objects elsewhere in the Galaxy.

    The astronomers used a technique called trigonometric parallax, first applied by Friedrich Wilhelm Bessel in 1838 to measure the distance to the star 61 Cygni in the constellation of the Swan. This technique measures the apparent shift in the sky position of a celestial object as seen from opposite sides of the Earth’s orbit around the Sun. This effect can be demonstrated by holding a finger in front of one’s nose and alternately closing each eye — the finger appears to jump from side to side.

    Measuring the angle of an object’s apparent shift in position this way allows astronomers to use simple trigonometry to directly calculate the distance to that object. The smaller the measured angle, the greater the distance is. In the framework of the Bar and Spiral Structure Legacy (BeSSeL) Survey, it is now possible to measure parallaxes a thousand times more accurate than Friedrich Bessel. The Very Long Baseline Array (VLBA), a continent-wide radio telescope system, with ten dish antennas distributed across North America, Hawaii, and the Caribbean, can measure the minuscule angles associated with great distances. In this case, the measurement was roughly equal to the angular size of a baseball on the Moon.

    “Using the VLBA, we now can accurately map the whole extent of our Galaxy,” says Alberto Sanna, of the Max Planck Institute for Radio Astronomy in Germany (MPIfR).

    The new VLBA observations, made in 2014 and 2015, measured a distance of more than 66,000 light-years to the star-forming region G007.47+00.05 on the opposite side of the Milky Way from the Sun, well past the Galaxy’s center in a distance of 27,000 light-years. The previous record for a parallax measurement was about 36,000 light-years.

    2

    Highly complex observations: The calculation of distances is principally simple, but requires highly accurate measurements of the angle of apparent shifts in an object’s position – only the VLBA has the capability to deliver such measurements.
    © Bill Saxton, NRAO/AUI/NSF; Robert Hurt, NASA.

    “Most of the stars and gas in our Galaxy are within this newly-measured distance from the Sun. With the VLBA, we now have the capability to measure enough distances to accurately trace the Galaxy’s spiral arms and learn their true shapes,” Sanna explains.

    The VLBA observations measured the distance to a region where new stars are being formed.

    Such regions include areas where molecules of water and methanol act as natural amplifiers of radio signals — masers, the radio-wave equivalent of lasers for light waves. This effect makes the radio signals bright and readily observable with radio telescopes.

    The Milky Way has hundreds of such star-forming regions that include masers. “So we have plenty of ‘mileposts’ to use for our mapping project. But this one is special: Looking all the way through the Milky Way, past its center, way out into the other side”, says the MPIfR’s Karl Menten.

    The astronomers’ goal is to finally reveal what our own Galaxy looks like if we could leave it, travel outward perhaps a million light-years, and view it face-on, rather than along the plane of its disk. This task will require many more observations and much painstaking work, but, the scientists say, the tools for the job now are in hand. How long will it take?

    “Within the next 10 years, we should have a fairly complete picture,” predicts Mark Reid of the Harvard-Smithsonian Center for Astrophysics.

    Science paper:
    Mapping Spiral Structure on the far side of the Milky Way, Science

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    The Center for Astrophysics combines the resources and research facilities of the Harvard College Observatory and the Smithsonian Astrophysical Observatory under a single director to pursue studies of those basic physical processes that determine the nature and evolution of the universe. The Smithsonian Astrophysical Observatory (SAO) is a bureau of the Smithsonian Institution, founded in 1890. The Harvard College Observatory (HCO), founded in 1839, is a research institution of the Faculty of Arts and Sciences, Harvard University, and provides facilities and substantial other support for teaching activities of the Department of Astronomy.



    MPIFR/Effelsberg Radio Telescope, Germany

    The Max Planck Institute for Radio Astronomy (German: Max-Planck-Institut für Radioastronomie) is located in Bonn, Germany. It is one of 80 institutes in the Max Planck Society (German: Max-Planck-Gesellschaft).

    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 Max Planck Society for the Advancement of Science (German: Max-Planck-Gesellschaft zur Förderung der Wissenschaften e. V.; abbreviated MPG) 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, MIT, Stanford and the US NIH). In terms of total research volume (unweighted by citations or impact), the Max Planck Society is only outranked by the Chinese Academy of Sciences, the Russian Academy of Sciences 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.

     
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