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  • richardmitnick 9:00 am on July 16, 2021 Permalink | Reply
    Tags: "Galactic fireworks- new ESO images reveal stunning features of nearby galaxies", , , , , ESO Very Large Telescope (VLT), , , ,   

    From European Southern Observatory [Observatoire européen austral][Europäische Südsternwarte] (EU) and From ALMA [The Atacama Large Millimeter/submillimeter Array] (CL) : “Galactic fireworks- new ESO images reveal stunning features of nearby galaxies” 

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    From European Southern Observatory [Observatoire européen austral][Europäische Südsternwarte] (EU)

    and

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

    16 July 2021

    Eric Emsellem
    European Southern Observatory
    Garching bei München, Germany
    Tel: +49 89 3200 6914
    Email: eric.emsellem@eso.org

    Eva Schinnerer
    MPG Institute for Astronomy [MPG Institut für Astronomie](DE)
    Heidelberg, Germany
    Tel: +49 6221 528 294
    Email: schinner@mpia.de

    Kathryn Kreckel
    Centre for Astronomy of Heidelberg University [Astronomisches Rechen-Institut: Zentrum für Astronomie] (DE)
    Heidelberg, Germany
    Email: kathryn.kreckel@uni-heidelberg.de

    Francesco Belfiore
    INAF – Arcetri Observatory [Arcetri Astrophysical Observatory Florence] (IT), Italy
    Email: francesco.belfiore@inaf.it

    Bárbara Ferreira
    ESO Media Manager
    Garching bei München, Germany
    Tel: +49 89 3200 6670
    Cell: +49 151 241 664 00
    Email: press@eso.org

    1
    A team of astronomers has released new observations of nearby galaxies that resemble colourful cosmic fireworks. The images, obtained with the European Southern Observatory’s Very Large Telescope (ESO’s VLT) [below], show different components of the galaxies in distinct colours, allowing astronomers to pinpoint the locations of young stars and the gas they warm up around them. By combining these new observations with data from the Atacama Large Millimeter/submillimeter Array (ALMA) [below], in which ESO is a partner, the team is helping shed new light on what triggers gas to form stars.

    2
    NGC 4303 as seen with MUSE on ESO’s VLT at several wavelengths of light.
    This image, taken by the Multi-Unit Spectroscopic Explorer (MUSE) on ESO’s Very Large Telescope (VLT), shows the nearby galaxy NGC 4303. NGC 4303 is a spiral galaxy, with a bar of stars and gas at its centre, located approximately 55 million light-years from Earth in the constellation Virgo. The image is an overlay of observations conducted at different wavelengths of light to map stellar populations and warm gas. The golden glows mainly correspond to clouds of ionised hydrogen, oxygen and sulphur gas, marking the presence of newly born stars, while the bluish regions in the background reveal the distribution of slightly older stars.

    The image was taken as part of the Physics at High Angular resolution in Nearby GalaxieS (PHANGS) project, which is making high-resolution observations of nearby galaxies with telescopes operating across the electromagnetic spectrum. Credit: ESO/PHANGS.

    3
    NGC 4254 as seen with MUSE on ESO’s VLT at several wavelengths of light.
    This image, taken with the Multi-Unit Spectroscopic Explorer (MUSE) on ESO’s Very Large Telescope (VLT), shows the nearby galaxy NGC 4254. NGC 4254 is a grand-design spiral galaxy located approximately 45 million light-years from Earth in the constellation Coma Berenices. The image is a combination of observations conducted at different wavelengths of light to map stellar populations and warm gas. The golden glows mainly correspond to clouds of ionised hydrogen, oxygen and sulphur gas, marking the presence of newly born stars, while the bluish regions in the background reveal the distribution of slightly older stars.

    The image was taken as part of the Physics at High Angular resolution in Nearby GalaxieS (PHANGS) project, which is making high-resolution observations of nearby galaxies with telescopes operating across the electromagnetic spectrum. Credit: ESO/PHANGS.

    See the full article for more individual images.

    Astronomers know that stars are born in clouds of gas, but what sets off star formation, and how galaxies as a whole play into it, remains a mystery. To understand this process, a team of researchers has observed various nearby galaxies with powerful telescopes on the ground and in space, scanning the different galactic regions involved in stellar births.

    “For the first time we are resolving individual units of star formation over a wide range of locations and environments in a sample that well represents the different types of galaxies,” says Eric Emsellem, an astronomer at ESO in Germany and lead of the VLT-based observations conducted as part of the Physics at High Angular resolution in Nearby GalaxieS (PHANGS) project. “We can directly observe the gas that gives birth to stars, we see the young stars themselves, and we witness their evolution through various phases.”

    Emsellem, who is also affiliated with the U Claude Lyon 1 [Université Claude Bernard Lyon 1] (FR), and his team have now released their latest set of galactic scans, taken with the Multi-Unit Spectroscopic Explorer (MUSE) instrument on ESO’s VLT in the Atacama Desert in Chile. They used MUSE to trace newborn stars and the warm gas around them, which is illuminated and heated up by the stars and acts as a smoking gun of ongoing star formation.

    The new MUSE images are now being combined with observations of the same galaxies taken with ALMA and released earlier this year. ALMA, which is also located in Chile, is especially well suited to mapping cold gas clouds — the parts of galaxies that provide the raw material out of which stars form.

    By combining MUSE and ALMA images astronomers can examine the galactic regions where star formation is happening, compared to where it is expected to happen, so as to better understand what triggers, boosts or holds back the birth of new stars. The resulting images are stunning, offering a spectacularly colourful insight into stellar nurseries in our neighbouring galaxies.

    “There are many mysteries we want to unravel,” says Kathryn Kreckel from the Ruprecht Karl University of Heidelberg [Ruprecht-Karls-Universität Heidelberg](DE) and PHANGS team member. “Are stars more often born in specific regions of their host galaxies — and, if so, why? And after stars are born how does their evolution influence the formation of new generations of stars?”

    Astronomers will now be able to answer these questions thanks to the wealth of MUSE and ALMA data the PHANGS team have obtained. MUSE collects spectra — the “bar codes” astronomers scan to unveil the properties and nature of cosmic objects — at every single location within its field of view, thus providing much richer information than traditional instruments. For the PHANGS project, MUSE observed 30 000 nebulae of warm gas and collected about 15 million spectra of different galactic regions. The ALMA observations, on the other hand, allowed astronomers to map around 100 000 cold-gas regions across 90 nearby galaxies, producing an unprecedentedly sharp atlas of stellar nurseries in the close Universe.

    In addition to ALMA and MUSE, the PHANGS project also features observations from the NASA/ESA Hubble Space Telescope.

    The various observatories were selected to allow the team to scan our galactic neighbours at different wavelengths (visible, near-infrared and radio), with each wavelength range unveiling distinct parts of the observed galaxies. “Their combination allows us to probe the various stages of stellar birth — from the formation of the stellar nurseries to the onset of star formation itself and the final destruction of the nurseries by the newly born stars — in more detail than is possible with individual observations,” says PHANGS team member Francesco Belfiore from INAF-Arcetri in Florence, Italy. “PHANGS is the first time we have been able to assemble such a complete view, taking images sharp enough to see the individual clouds, stars, and nebulae that signify forming stars.”

    The work carried out by the PHANGS project will be further honed by upcoming telescopes and instruments, such as NASA’s James Webb Space Telescope.

    The data obtained in this way will lay further groundwork for observations with ESO’s future Extremely Large Telescope (ELT) [below], which will start operating later this decade and will enable an even more detailed look at the structures of stellar nurseries.

    “As amazing as PHANGS is, the resolution of the maps that we produce is just sufficient to identify and separate individual star-forming clouds, but not good enough to see what’s happening inside them in detail,” pointed out Eva Schinnerer, a research group leader at the Max Planck Institute for Astronomy in Germany and principal investigator of the PHANGS project, under which the new observations were conducted. “New observational efforts by our team and others are pushing the boundary in this direction, so we have decades of exciting discoveries ahead of us.”

    More information

    The international PHANGS team is composed of over 90 scientists ranging from Master students to retirees working at 30 institutions across four continents. The MUSE data reduction working group within PHANGS is being led by Eric Emsellem (European Southern Observatory, Garching, Germany and Centre de Recherche Astrophysique de Lyon, Université de Lyon, ENS de Lyon, Saint-Genis Laval, France) and includes Francesco Belfiore (INAF Osservatorio Astrofisico di Arcetri, Florence, Italy), Guillermo Blanc, Carnegie Observatories, Pasadena, US), Enrico Congiu (Universidad de Chile, Santiago, Chile and Las Campanas Observatory, Carnegie Institution for Science, Atacama Region, Chile), Brent Groves (The University of Western Australia (AU), Perth, Australia), I-Ting Ho (Max Planck Institute for Astronomy, Heidelberg, Germany [MPIA]), Kathryn Kreckel (Heidelberg University, Heidelberg, Germany), Rebecca McElroy (Sydney Institute for Astronomy (SIfA) (AU), Sydney, Australia), Ismael Pessa (MPIA), Patricia Sanchez-Blazquez (Complutense University of Madrid[Universidad Complutense Madrid] Institute of Particle and Cosmos Physics [Instituto de Física de Partículas y Cosmos] (ES), Madrid, Spain), Francesco Santoro (MPIA), Fabian Scheuermann (Heidelberg University, Heidelberg, Germany) and Eva Schinnerer (MPIA).

    Go to the ESO public image archive to see a sample of PHANGS images.

    See the full article here .


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

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

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    European Southern Observatory [Observatoire européen austral][Europäische Südsternwarte] (EU) is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

    European Southern Observatory(EU) , Very Large Telescope at Cerro Paranal in the Atacama Desert •ANTU (UT1; The Sun ) •KUEYEN (UT2; The Moon ) •MELIPAL (UT3; The Southern Cross ), and •YEPUN (UT4; Venus – as evening star). Elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo. [/caption]


    ESO Very Large Telescope 4 lasers on Yepun (CL)

    European Southern Observatory(EU)/MPG Institute for Radio Astronomy [MPG Institut für Radioastronomie](DE) ESO’s Atacama Pathfinder Experiment(CL) high on the Chajnantor plateau in Chile’s Atacama region, at an altitude of over 4,800 m (15,700 ft).

    European Southern Observatory(EU) ExTrA telescopes at erro LaSilla at an altitude of 2400 metres.

     
  • richardmitnick 8:49 am on April 6, 2021 Permalink | Reply
    Tags: "An image of a piece of the cosmic web", , , , , , ESO MUSE on the VLT, ESO Very Large Telescope (VLT), ,   

    From Leiden University [Universiteit Leiden] (NL) via EarthSky News: “An image of a piece of the cosmic web” 


    From Leiden University [Universiteit Leiden] (NL)

    via

    EarthSky News

    April 5, 2021
    Deborah Byrd

    An international team of astronomers has mapped a piece of the cosmic web without using bright quasars for the first time. They did it by turning a powerful instrument to a single region of the sky for hundreds of hours.

    1
    This image looks in the direction of our constellation Fornax the Furnace, to a time 2 billion years after the Big Bang. Each point of light is a galaxy. You can see a filament between the galaxies, tracing the path of the cosmic web. See the full image, below. Credit: Roland Bacon et al./ (c) European Southern Observatory(EU) / National Aeronautics Space Agency(US)

    In recent decades, astronomers have begun speaking of the large-scale structure of our universe as a cosmic web. This great web provides the scaffolding of our universe. Its walls are made of both dark and visible matter (in the form of billions of galaxies and great quantities of gases), and giant voids are thought to lie between the web walls. Previously, astronomers have said they’ve mapped parts of the cosmic web using distant, bright quasars as a guide. On March 18, 2021, an international team of astronomers published a new study in the journal Astronomy & Astrophysics, showing an image of a piece of the cosmic web – without using bright quasars – for the first time. They did it by managing to capture the light of groups of stars and galaxies that had been scattered by gas filaments in the web.

    This is light from about two billion years after the Big Bang, the event in which our universe is thought to have begun, these astronomers said.

    Their study is part of what they call the MUSE Extremely Deep Field, named for the MUSE instrument (the Multi Unit Spectroscopic Explorer), which they used over six nights (between August 2018 and January 2019) mounted on the Very Large Telescope in northern Chile.

    European Southern Observatory(EU) , Very Large Telescope at Cerro Paranal in the Atacama Desert •ANTU (UT1; The Sun ) •KUEYEN (UT2; The Moon ) •MELIPAL (UT3; The Southern Cross ), and •YEPUN (UT4; Venus – as evening star). Elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo.

    They were looking toward the famous Hubble Ultra Deep Field – a mind-boggling image of tiny patch of sky, located in the direction to the southern constellation Fornax – acquired between September 2003 and January 2004.

    That original Hubble image shows an estimated 10,000 galaxies. The new MUSE study shows this same patch of sky, along with visible filaments of the cosmic web. Astronomer Roland Bacon of the Lyon Astrophysical Research Center [Centre de Recherche Astrophysique de Lyon] (FR) led the team who made these observations. These scientists said in their paper:

    “Galaxies form within large cosmic filaments of gas and dark matter, which are delineated by massive bright galaxies. Smaller galaxies are also believed to gather with the massive galaxies in these filaments, but they are too faint to be observed. With the MUSE Extremely Deep Field, a 140-hour deep MUSE observation in the Hubble Ultra-Deep Field, Bacon et al. have discovered diffuse extended Ly-alpha emission from redshift 3.1 to 4.5, tracing cosmic filaments on scales of several megaparsecs [editor’s note: a megaparsec is 3,260,000 light-years] …”

    2
    Multiple studies prior to this one suggest a weblike structure for our universe, at the largest scales. This image – generated in a 2020 study – is computer-generated. It suggests the distribution of dark matter in the universe, along with ordinary matter, takes the form of a cosmic web. Image via J. Wang; S. Bose/ Harvard Smithsonian Center for Astrophysics(US).

    The team said their observations showed that potentially more than half of the scattered light in their image comes not from large bright radiating sources like bright galaxies or quasars, but from a sea of previously undiscovered galaxies of very low luminosity that are far too dim to be observed individually. They said in a statement:

    “The results strengthen the hypothesis that the young universe consisted of vast numbers of, small groups of freshly formed stars.”

    Co-author Joop Schaye of Leiden University in the Netherlands said:

    “We think that the light we are seeing comes mainly from young galaxies, each containing millions of times fewer stars than our own Milky Way. Such tiny galaxies were likely responsible for the end of the cosmic dark ages, when less than a billion years after the Big Bang, the universe was illuminated and heated by the first generations of stars.”

    Co-author Michael Maseda, also of Leiden Observatory, added:

    “The MUSE observations thus not only give us a picture of the cosmic web, but also provide new evidence for the existence of the extremely small galaxies that play such a crucial role in models of the early universe.”

    These astronomers said they’d like to map larger pieces of the cosmic web. That’s why they’re working to improve the MUSE instrument so that it provides a two to four times larger field of view.

    4
    Here’s the image – part of the MUSE Extremely Deep Field – acquired by scientists in a study published in March 2021. What you’re seeing here are galaxies, connected by faint filaments – together making up “strands” in the cosmic web – extending over a distance of more than 13 million light-years. The distance shown in this image is roughly equivalent to 150 of our home galaxies (150 Milky Ways), placed back to back. Image via Bacon et al.

    See the full article here.

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    Universiteit Leiden Heijmans onderhoudt

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

     
  • richardmitnick 2:54 pm on September 10, 2020 Permalink | Reply
    Tags: "Hubble Observations Suggest a Missing Ingredient in Dark Matter Theories", A discrepancy between the theoretical models of how dark matter should be distributed in galaxy clusters and observations of dark matter's grip on clusters., , , , , Dark matter does not emit absorb or reflect light. Its presence is only known through its gravitational pull on visible matter in space., ESO Very Large Telescope (VLT), , One way astronomers can detect dark matter is by measuring how its gravity distorts space- an effect called gravitational lensing., Researchers found that small-scale concentrations of dark matter in clusters produce gravitational lensing effects that are 10 times stronger than expected., Small dense concentrations of dark matter that bend and magnify light much more strongly than expected.   

    From NASA/ESA Hubble Telescope: “Hubble Observations Suggest a Missing Ingredient in Dark Matter Theories” 

    NASA/ESA Hubble Telescope.


    From NASA/ESA Hubble Telescope

    Sept. 10, 2020
    Claire Andreoli
    NASA’s Goddard Space Flight Center, Greenbelt, Md.
    301-286-1940
    claire.andreoli@nasa.gov

    Donna Weaver
    Space Telescope Science Institute, Baltimore
    410-338-4493
    dweaver@stsci.edu

    Ray Villard
    Space Telescope Science Institute, Baltimore
    410-338-4514
    villard@stsci.edu

    Priyamvada Natarajan
    Yale University, New Haven, Conn.
    203-436-4833
    priyamvada.natarajan@yale.edu

    Massimo Meneghetti
    INAF-Observatory of Astrophysics and Science, Bologna, Italy
    massimo.meneghetti@inaf.it

    Astronomers have discovered that there may be a missing ingredient in our cosmic recipe of how dark matter behaves.

    They have uncovered a discrepancy between the theoretical models of how dark matter should be distributed in galaxy clusters, and observations of dark matter’s grip on clusters.


    Astronomers seem to have revealed a puzzling detail in the way dark matter behaves. They found small, dense concentrations of dark matter that bend and magnify light much more strongly than expected.
    Credits: NASA’s Goddard Space Flight Center.

    Dark matter does not emit, absorb, or reflect light. Its presence is only known through its gravitational pull on visible matter in space. Therefore, dark matter remains as elusive as Alice in Wonderland’s Cheshire Cat – where you only see its grin (in the form of gravity) but not the animal itself.

    One way astronomers can detect dark matter is by measuring how its gravity distorts space, an effect called gravitational lensing.

    Researchers found that small-scale concentrations of dark matter in clusters produce gravitational lensing effects that are 10 times stronger than expected. This evidence is based on unprecedentedly detailed observations of several massive galaxy clusters by NASA’s Hubble Space Telescope and the European Southern Observatory’s Very Large Telescope (VLT) in Chile.

    ESO VLT at Cerro Paranal in the Atacama Desert, •ANTU (UT1; The Sun ),
    •KUEYEN (UT2; The Moon ),
    •MELIPAL (UT3; The Southern Cross ), and
    •YEPUN (UT4; Venus – as evening star).
    elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo.

    1
    This Hubble Space Telescope image shows the massive galaxy cluster MACS J1206. Embedded within the cluster are the distorted images of distant background galaxies, seen as arcs and smeared features. These distortions are caused by the amount of dark matter in the cluster, whose gravity bends and magnifies the light from faraway galaxies. This effect, called gravitational lensing, allows astronomers to study remote galaxies that would otherwise be too faint to see.

    Gravitational Lensing

    Gravitational Lensing NASA/ESA.

    Several of the cluster galaxies are sufficiently massive and dense to also distort and magnify faraway sources. The galaxies in the three pullouts represent examples of such effects. In the snapshots at upper right and bottom, two distant, blue galaxies are lensed by the foreground, redder cluster galaxies, forming rings and multiple images of the remote objects. The red blobs around the galaxy at upper left denote emission from clouds of hydrogen in a single distant source. The source, seen four times because of lensing, may be a faint galaxy. These blobs were detected by the Multi-Unit Spectroscopic Explorer (MUSE) at the European Southern Observatory’s Very Large Telescope (VLT) in Chile.

    ESO MUSE on the VLT on Yepun (UT4).

    The blobs do not appear in the Hubble images. MACS J1206 is part of the Cluster Lensing And Supernova survey with Hubble (CLASH) and is one of three galaxy clusters the researchers studied with Hubble and the VLT. The Hubble image is a combination of visible- and infrared-light observations taken in 2011 by the Advanced Camera for Surveys and Wide Field Camera 3.

    NASA Hubble Advanced Camera for Surveys.

    NASA/ESA Hubble WFC3

    Credits: NASA, ESA, P. Natarajan (Yale University), G. Caminha (University of Groningen), M. Meneghetti (INAF-Observatory of Astrophysics and Space Science of Bologna), the CLASH-VLT/Zooming teams; acknowledgment: NASA, ESA, M. Postman (STScI), the CLASH team.

    Galaxy clusters, the most massive structures in the universe composed of individual member galaxies, are the largest repositories of dark matter. Not only are they held together largely by dark matter’s gravity, the individual cluster galaxies are themselves replete with dark matter. Dark matter in clusters is therefore distributed on both large and small scales.

    “Galaxy clusters are ideal laboratories to understand if computer simulations of the universe reliably reproduce what we can infer about dark matter and its interplay with luminous matter,” said Massimo Meneghetti of the INAF (National Institute for Astrophysics)-Observatory of Astrophysics and Space Science of Bologna in Italy, the study’s lead author.

    “We have done a lot of careful testing in comparing the simulations and data in this study, and our finding of the mismatch persists,” Meneghetti continued. “One possible origin for this discrepancy is that we may be missing some key physics in the simulations.”

    Priyamvada Natarajan of Yale University in New Haven, Connecticut, one of the senior theorists on the team, added, “There’s a feature of the real universe that we are simply not capturing in our current theoretical models. This could signal a gap in our current understanding of the nature of dark matter and its properties, as these exquisite data have permitted us to probe the detailed distribution of dark matter on the smallest scales.”

    The team’s paper will appear in the Sept. 11 issue of the journal Science.

    The distribution of dark matter in clusters is mapped via the bending of light, or the gravitational lensing effect, they produce. The gravity of dark matter magnifies and warps light from distant background objects, much like a funhouse mirror, producing distortions and sometimes multiple images of the same distant galaxy. The higher the concentration of dark matter in a cluster, the more dramatic its light bending.

    Hubble’s crisp images, coupled with spectra from the VLT, helped the team produce an accurate, high-fidelity dark-matter map. They identified dozens of multiply imaged, lensed, background galaxies. By measuring the lensing distortions, astronomers could trace out the amount and distribution of dark matter.

    The three key galaxy clusters used in the analysis, MACS J1206.2-0847, MACS J0416.1-2403, and Abell S1063, were part of two Hubble surveys: The Frontier Fields and the Cluster Lensing And Supernova survey with Hubble (CLASH) programs.

    To the team’s surprise, the Hubble images also revealed smaller-scale arcs and distorted images nested within the larger-scale lens distortions in each cluster’s core, where the most massive galaxies reside.

    The researchers believe that the embedded lenses are produced by the gravity of dense concentrations of dark matter associated with individual cluster galaxies. Dark matter’s distribution in the inner regions of individual galaxies is known to enhance the cluster’s overall lensing effect.

    The researchers believe that the embedded lenses are produced by the gravity of dense concentrations of dark matter associated with individual cluster galaxies. Dark matter’s distribution in the inner regions of individual galaxies is known to enhance the cluster’s overall lensing effect.

    Follow-up spectroscopic observations added to the study by measuring the velocity of the stars orbiting inside several of the cluster galaxies. “Based on our spectroscopic study, we were able to associate the galaxies with each cluster and estimate their distances,” said team member Piero Rosati of the University of Ferrara in Italy.

    “The stars’ speed gave us an estimate of each individual galaxy’s mass, including the amount of dark matter,” added team member Pietro Bergamini of the INAF-Observatory of Astrophysics and Space Science in Bologna, Italy.

    The team compared the dark-matter maps with samples of simulated galaxy clusters with similar masses, located at roughly the same distances as the observed clusters. The clusters in the computer simulations did not show the same level of dark-matter concentration on the smallest scales – the scales associated with individual cluster galaxies as seen in the universe.

    The team looks forward to continuing their stress-testing of the standard dark-matter model to pin down its intriguing nature.

    NASA’s planned Nancy Grace Roman Space Telescope will detect even more remote galaxies through gravitational lensing by massive galaxy clusters.

    NASA/Nancy Grace Roman Space Telescope.

    The observations will enlarge the sample of clusters that astronomers can analyze to further test the dark-matter models.

    See the full article here .


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    The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI), is a free-standing science center, located on the campus of The Johns Hopkins University and operated by the Association of Universities for Research in Astronomy (AURA) for NASA, conducts Hubble science operations.

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  • richardmitnick 8:58 am on April 16, 2020 Permalink | Reply
    Tags: "ESO Telescope Sees Star Dance Around Supermassive Black Hole Proves Einstein Right", , , , , ESO Very Large Telescope (VLT)   

    From European Southern Observatory: “ESO Telescope Sees Star Dance Around Supermassive Black Hole, Proves Einstein Right” 

    ESO 50 Large

    From European Southern Observatory

    16 April 2020
    Reinhard Genzel
    Director, Max Planck Institute for Extraterrestrial Physics
    Garching bei München, Germany
    Tel: +49 89 30000 3280
    Email: genzel@mpe.mpg.de

    Stefan Gillessen
    Max-Planck Institute for Extraterrestrial Physics
    Garching bei München, Germany
    Tel: +49 89 30000 3839
    Cell: +49 176 99 66 41 39
    Email: ste@mpe.mpg.de

    Frank Eisenhauer
    Max-Planck Institute for Extraterrestrial Physics
    Garching bei München, Germany
    Tel: +49 89 30000 3563
    Cell: +49 162 3105080
    Email: eisenhau@mpe.mpg.de

    Paulo Garcia
    Faculdade de Engenharia, Universidade do Porto and Centro de Astrofísica e Gravitação, IST, Universidade de Lisboa, Portugal
    Porto, Portugal
    Cell: +351 963235785
    Email: pgarcia@fe.up.pt

    Karine Perraut
    IPAG of Université Grenoble Alpes/CNRS
    Grenoble, France
    Email: karine.perraut@univ-grenoble-alpes.fr

    Guy Perrin
    LESIA – Observatoire de Paris – PSL
    Meudon, France
    Email: guy.perrin@observatoiredeparis.psl.eu

    Andreas Eckart
    1st Institute of Physics, University of Cologne
    Cologne, Germany
    Tel: +49 221 470 3546
    Email: eckart@ph1.uni-koeln.de

    Bárbara Ferreira
    ESO Public Information Officer
    Garching bei München, Germany
    Tel: +49 89 3200 6670
    Cell: +49 151 241 664 00
    Email: pio@eso.org

    1
    Observations made with ESO’s Very Large Telescope (VLT) [below] have revealed for the first time that a star orbiting the supermassive black hole at the centre of the Milky Way moves just as predicted by Einstein’s general theory of relativity. Its orbit is shaped like a rosette and not like an ellipse as predicted by Newton’s theory of gravity. This long-sought-after result was made possible by increasingly precise measurements over nearly 30 years, which have enabled scientists to unlock the mysteries of the behemoth lurking at the heart of our galaxy.This effect, known as Schwarzschild precession, had never before been measured for a star around a supermassive black hole.

    SGR A* , the supermassive black hole at the center of the Milky Way. NASA’s Chandra X-Ray Observatory

    SgrA* NASA/Chandra supermassive black hole at the center of the Milky Way, X-ray image of the center of our galaxy, where the supermassive black hole Sagittarius A* resides. Image via X-ray: NASA/UMass/D.Wang et al., IR: NASA/STScI.

    Sgr A* from ESO VLT

    This artist’s impression illustrates the precession of the star’s orbit, with the effect exaggerated for easier visualisation. Credit: ESO/L. Calçada

    2
    This simulation shows the orbits of stars very close to the supermassive black hole at the heart of the Milky Way. One of these stars, named S2, orbits every 16 years and is passing very close to the black hole in May 2018. This is a perfect laboratory to test gravitational physics and specifically Einstein’s general theory of relativity. Research into S2’s orbit was presented in a paper entitled “Detection of the Gravitational Redshift in the Orbit of the Star S2 near the Galactic Centre Massive Black Hole“, by the GRAVITY Collaboration, which appeared in the journal Astronomy & Astrophysics on 26 July 2018. Credit: ESO/L. Calçada/spaceengine.org

    3
    This visible light wide-field view shows the rich star clouds in the constellation of Sagittarius (the Archer) in the direction of the centre of our Milky Way galaxy. The entire image is filled with vast numbers of stars — but far more remain hidden behind clouds of dust and are only revealed in infrared images. This view was created from photographs in red and blue light and forming part of the Digitized Sky Survey 2. The field of view is approximately 3.5 degrees x 3.6 degrees. Credit:
    ESO and Digitized Sky Survey 2. Acknowledgment: Davide De Martin and S. Guisard (http://www.eso.org/~sguisard)

    ESOcast 219 Light: Star Dance Around Supermassive Black Hole

    The ESOcast Light is a series of short videos bringing you the wonders of the Universe in bite-sized pieces. The ESOcast Light episodes will not be replacing the standard, longer ESOcasts, but complement them with current astronomy news and images in ESO press releases.
    Credit:
    ESO
    Directed by: Herbert Zodet.
    Editing: Herbert Zodet.
    Web and technical support: Gurvan Bazin and Raquel Yumi Shida.
    Written by: Caitlyn Buongiorno, Stephanie Rowlands and Bárbara Ferreira.
    Music: John Stanford – Deep Space (http://www.johnstanfordmusic.com).
    Footage and photos: ESO, L. Calçada and Daniele Gasparri (http://www.astroatacama.com).
    Scientific consultants: Paola Amico and Mariya Lyubenova.

    Artist’s animation of S2’s precession effect

    Observations made with ESO’s Very Large Telescope (VLT) have revealed for the first time that a star, S2, orbiting the supermassive black hole at the centre of the Milky Way moves just as predicted by Einstein’s theory of general relativity. Most stars and planets have a non-circular orbit and therefore move closer and further away from the object they are rotating around. S2’s orbit precesses, meaning that the location of its closest point to the supermassive black hole changes with each turn, such that the next orbit is rotated with regard to the previous one, creating a rosette shape. This effect, known as Schwarzschild precession, had never before been measured for a star around a supermassive black hole.
    This schematic illustration shows S2’s orbit around Sagitarius A*, the supermassive black hole at the centre of the Milky Way. The precession movement is exaggerated for easier viewing. Credit: ESO/L. Calçada

    Interview with Reinhard Genzel (in English)

    In this video interview, Reinhard Genzel, the Director at the Max Planck Institute for Extraterrestrial Physics, talks about his team’s study of stars around the supermassive black hole at the centre of the Milky Way, including the recent discovery of the orbital precession of the S2 star. The study was made possible thanks to a fleet of instruments at ESO’s Very Large Telescope. Credit: MPE / TWENTYTWO Film GmbH, ESO/L. Calçada

    “Einstein’s General Relativity predicts that bound orbits of one object around another are not closed, as in Newtonian Gravity, but precess forwards in the plane of motion. This famous effect — first seen in the orbit of the planet Mercury around the Sun — was the first evidence in favour of General Relativity. One hundred years later we have now detected the same effect in the motion of a star orbiting the compact radio source Sagittarius A* at the centre of the Milky Way. This observational breakthrough strengthens the evidence that Sagittarius A* must be a supermassive black hole of 4 million times the mass of the Sun,” says Reinhard Genzel, Director at the Max Planck Institute for Extraterrestrial Physics (MPE) in Garching, Germany and the architect of the 30-year-long programme that led to this result [see video provided above].

    Located 26 000 light-years from the Sun, Sagittarius A* and the dense cluster of stars around it provide a unique laboratory for testing physics in an otherwise unexplored and extreme regime of gravity. One of these stars, S2, sweeps in towards the supermassive black hole to a closest distance less than 20 billion kilometres (one hundred and twenty times the distance between the Sun and Earth), making it one of the closest stars ever found in orbit around the massive giant.

    Star S0-2 Andrea Ghez Keck/UCLA Galactic Center Group at SGR A*, the supermassive black hole at the center of the milky way

    At its closest approach to the black hole, S2 is hurtling through space at almost three percent of the speed of light, completing an orbit once every 16 years. “After following the star in its orbit for over two and a half decades, our exquisite measurements robustly detect S2’s Schwarzschild precession in its path around Sagittarius A*,” says Stefan Gillessen of the MPE, who led the analysis of the measurements published today in the journal Astronomy & Astrophysics [below].

    Most stars and planets have a non-circular orbit and therefore move closer to and further away from the object they are rotating around. S2’s orbit precesses, meaning that the location of its closest point to the supermassive black hole changes with each turn, such that the next orbit is rotated with regard to the previous one, creating a rosette shape. General Relativity provides a precise prediction of how much its orbit changes and the latest measurements from this research exactly match the theory. This effect, known as Schwarzschild precession, had never before been measured for a star around a supermassive black hole.

    The study with ESO’s VLT also helps scientists learn more about the vicinity of the supermassive black hole at the centre of our galaxy. “Because the S2 measurements follow General Relativity so well, we can set stringent limits on how much invisible material, such as distributed dark matter or possible smaller black holes, is present around Sagittarius A*. This is of great interest for understanding the formation and evolution of supermassive black holes,” say Guy Perrin and Karine Perraut, the French lead scientists of the project.

    This result is the culmination of 27 years of observations of the S2 star using, for the best part of this time, a fleet of instruments at ESO’s VLT, located in the Atacama Desert in Chile. The number of data points marking the star’s position and velocity attests to the thoroughness and accuracy of the new research: the team made over 330 measurements in total, using the GRAVITY, SINFONI and NACO instruments. Because S2 takes years to orbit the supermassive black hole, it was crucial to follow the star for close to three decades, to unravel the intricacies of its orbital movement.

    ESO GRAVITY in the VLTI

    ESO SINFONI installed at the Cassegrain focus of UT3 on the VLT

    ESO/NACO on Unit Telescope 1 (UT1).

    The research was conducted by an international team led by Frank Eisenhauer of the MPE with collaborators from France, Portugal, Germany and ESO. The team make up the GRAVITY collaboration, named after the instrument they developed for the VLT Interferometer, which combines the light of all four 8-metre VLT telescopes into a super-telescope (with a resolution equivalent to that of a telescope 130 metres in diameter).

    2009 ESO VLTI Interferometer image, Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level, • ANTU (UT1; The Sun ),
    •KUEYEN (UT2; The Moon ),
    •MELIPAL (UT3; The Southern Cross ), and
    •YEPUN (UT4; Venus – as evening star).

    The same team reported in 2018 [above] another effect predicted by General Relativity: they saw the light received from S2 being stretched to longer wavelengths as the star passed close to Sagittarius A*. “Our previous result has shown that the light emitted from the star experiences General Relativity. Now we have shown that the star itself senses the effects of General Relativity,” says Paulo Garcia, a researcher at Portugal’s Centre for Astrophysics and Gravitation and one of the lead scientists of the GRAVITY project.

    With ESO’s upcoming Extremely Large Telescope [below], the team believes that they would be able to see much fainter stars orbiting even closer to the supermassive black hole. “If we are lucky, we might capture stars close enough that they actually feel the rotation, the spin, of the black hole,” says Andreas Eckart from Cologne University, another of the lead scientists of the project. This would mean astronomers would be able to measure the two quantities, spin and mass, that characterise Sagittarius A* and define space and time around it. “That would be again a completely different level of testing relativity,” says Eckart.
    More information

    This research was presented in the paper “Detection of the Schwarzschild precession in the orbit of the star S2 near the Galactic centre massive black hole” to appear in Astronomy & Astrophysics

    The GRAVITY Collaboration team is composed of R. Abuter (European Southern Observatory, Garching, Germany [ESO]), A. Amorim (Universidade de Lisboa – Faculdade de Ciências, Portugal and Centro de Astrofísica e Gravitação, IST, Universidade de Lisboa, Portugal [CENTRA]), M. Bauböck (Max Planck Institute for Extraterrestrial Physics, Garching, Germany [MPE]), J.P. Berger (Univ. Grenoble Alpes, CNRS, Grenoble, France [IPAG] and ESO), H. Bonnet (ESO), W. Brandner (Max Planck Institute for Astronomy, Heidelberg, Germany [MPIA]), V. Cardoso (CENTRA and CERN, Genève, Switzerland), Y. Clénet (Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université de Paris, Meudon, France [LESIA], P.T. de Zeeuw (Sterrewacht Leiden, Leiden University, The Netherlands and MPE), J. Dexter (Department of Astrophysical & Planetary Sciences, JILA, Duane Physics Bldg.,University of Colorado, Boulder, USA and MPE), A. Eckart (1st Institute of Physics, University of Cologne, Germany [Cologne] and Max Planck Institute for Radio Astronomy, Bonn, Germany), F. Eisenhauer (MPE), N.M. Förster Schreiber (MPE), P. Garcia (Faculdade de Engenharia, Universidade do Porto, Portugal and CENTRA), F. Gao (MPE), E. Gendron (LESIA), R. Genzel (MPE, Departments of Physics and Astronomy, Le Conte Hall, University of California, Berkeley, USA), S. Gillessen (MPE), M. Habibi (MPE), X. Haubois (European Southern Observatory, Santiago, Chile [ESO Chile]), T. Henning (MPIA), S. Hippler (MPIA), M. Horrobin (Cologne), A. Jiménez-Rosales (MPE), L. Jochum (ESO Chile), L. Jocou (IPAG), A. Kaufer (ESO Chile), P. Kervella (LESIA), S. Lacour (LESIA), V. Lapeyrère (LESIA), J.-B. Le Bouquin (IPAG), P. Léna (LESIA), M. Nowak (Institute of Astronomy, Cambridge, UK and LESIA), T. Ott (MPE), T. Paumard (LESIA), K. Perraut (IPAG), G. Perrin (LESIA), O. Pfuhl (ESO, MPE), G. Rodríguez-Coira (LESIA), J. Shangguan (MPE), S. Scheithauer (MPIA), J. Stadler (MPE), O. Straub (MPE), C. Straubmeier (Cologne), E. Sturm (MPE), L.J. Tacconi (MPE), F. Vincent (LESIA), S. von Fellenberg (MPE), I. Waisberg (Department of Particle Physics & Astrophysics, Weizmann Institute of Science, Israel and MPE), F. Widmann (MPE), E. Wieprecht (MPE), E. Wiezorrek (MPE), J. Woillez (ESO), and S. Yazici (MPE, Cologne).

    See the full article here .


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    ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre EEuropean Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

    ESO/Cerro LaSilla, 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO VLT at Cerro Paranal in the Atacama Desert

    ESO VLT 4 lasers on Yepun

    Glistening against the awesome backdrop of the night sky above ESO_s Paranal Observatory, four laser beams project out into the darkness from Unit Telescope 4 UT4 of the VLT.

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

    ESO/E-ELT,to be on top of Cerro Armazones in the Atacama Desert of northern Chile. located at the summit of the mountain at an altitude of 3,060 metres (10,040 ft).


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

    A novel gamma ray telescope under construction on Mount Hopkins, Arizona. a large project known as the Čerenkov Telescope Array, composed of hundreds of similar telescopes to be situated in the Canary Islands and Chile. The telescope on Mount Hopkins will be fitted with a prototype high-speed camera, assembled at the University of Wisconsin–Madison, and capable of taking pictures at a billion frames per second. Credit: Vladimir Vassiliev

     
  • richardmitnick 11:09 am on December 27, 2019 Permalink | Reply
    Tags: "Mapping the Remains of Supernovae", , , , , ESO Very Large Telescope (VLT), ,   

    From UNSW via Scientific American: “Mapping the Remains of Supernovae” 

    U NSW bloc

    From University of New South Wales

    via

    Scientific American

    Scientific American

    Scientific American January 2020 Issue
    Rachel Berkowitz

    A new tool provides detailed, 3-D chemical view of exploded star systems.

    1
    Light emitted by two supernova remnants. Green indicates charged iron. Credit: I. R. SEITENZAHL ET AL.

    When a dense stellar core called a white dwarf acquires enough material from a companion star orbiting nearby, it burns up in the nuclear fusion blast of a Type Ia supernova. This ejects freshly synthesized elements that mix with interstellar gas and eventually form stars and galaxies. But astrophysicists still don’t know the specific conditions that ignite these explosions.

    Ivo Seitenzahl, an astrophysicist at University of New South Wales Canberra, and his colleagues used the upgraded Very Large Telescope (VLT) in Chile to build unprecedented 3-D chemical maps of the debris left behind by these supernovae.

    ESO VLT at Cerro Paranal in the Atacama Desert, •ANTU (UT1; The Sun ),
    •KUEYEN (UT2; The Moon ),
    •MELIPAL (UT3; The Southern Cross ), and
    •YEPUN (UT4; Venus – as evening star).
    elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo,

    These maps can help scientists work backward to “constrain the fundamental properties of these explosions, including the amount of kinetic energy and the mass of the exploding star,” says Carles Badenes, an astrophysicist at the University of Pittsburgh, who was not involved in the study.

    During a supernova event, heavy elements shoot from the white dwarf’s core at supersonic speeds. This drives a shock wave outward through the surrounding interstellar gas and dust, and another shock wave bounces backward into the explosion debris, eventually heating the ejected matter to x-ray-emitting temperatures. Scientists can learn about a supernova remnant’s composition from these x-rays—but current x-ray instruments lack the resolution to measure the movement of ejected material.

    Seitenzahl’s group used visible-light data from the VLT to analyze supernova remnants in a new way, described in July in Physical Review Letters. Basic models suggest that Type Ia supernovae produce most of the universe’s iron. That iron should hold a stronger electrical charge the farther it is behind the supernova’s shock wave and emit distinctive visible wavelengths of light; however, those emissions were too faint to detect before the VLT’s recent instrument upgrade.

    With the upgrade, the researchers detected concentric layers of charged iron within supernova remnants in the Large Magellanic Cloud, a nearby satellite galaxy of our Milky Way. From distortion patterns in light released by the charged iron, they determined the inward shock wave’s velocity in Type Ia supernova remnants for the first time. “This is exciting science that’s been enabled by new technology, used on precisely the type of [supernova] that needs it,” says Dan Milisavljevic, an astronomer at Purdue University, who was also not involved in the work.

    Seitenzahl’s group also found that one particular supernova originated from a white dwarf whose mass was thought to be too small to trigger such an explosion, suggesting there is still more to learn about this process. Further work could reveal more details about the chemicals produced in Type Ia supernovae, whether an explosion initiates on the surface or interior of the star and what conditions trigger the blast.

    See the full article here .


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  • richardmitnick 2:23 pm on August 2, 2019 Permalink | Reply
    Tags: , , , , ESO Very Large Telescope (VLT), MUSE on the VLT on Yepun (UT4),   

    From physicsworld.com: “Optical tomography brings exploding stars into view” 

    physicsworld
    From physicsworld.com

    02 Aug 2019

    1
    The new optical tomography technique has been used to produce optical emission images of the remnants of supernovae in the Large Magellanic Cloud (Courtesy: PRL/I R Seitenzahl et al.)

    Large Magellanic Cloud. Adrian Pingstone December 2003

    New updates to the Very Large Telescope (VLT) in Chile have allowed a team of astronomers to detect elusive optical emissions in the remnants of three type Ia supernovae.

    ESO VLT at Cerro Paranal in the Atacama Desert, •ANTU (UT1; The Sun ),
    •KUEYEN (UT2; The Moon ),
    •MELIPAL (UT3; The Southern Cross ), and
    •YEPUN (UT4; Venus – as evening star).
    elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo,

    The international team, led by Ivo Seitenzahl at the University of New South Wales in Canberra, used the improvements to observe Doppler shifts in the spectral lines emitted by highly ionized states of iron and sulphur in the gases.

    Formed when white dwarf stars collapse in colossal thermonuclear explosions, type Ia supernovae are known to influence processes including star formation and galaxy evolution. Extensive optical surveys have provided astronomers with huge amounts of data about the events, allowing for reliable theoretical models to explain their formation and evolution.

    Among the predictions of these models are that type Ia supernovae must be triggered by white dwarf stars above the Chandrasekhar mass limit, which can be reached by accreting material from companion stars. In addition, the models predict that different elements will be more abundant in different layers of the explosion due to the onion-like structure of the white dwarf’s progenitor star, in which heavier elements reside in layers closer to the core.

    Yet despite their successes so far, these models remain plagued with uncertainties due to limitations in previous observations of the events. In the first year of a supernova, for example, its remnants are optically thick, which means that astronomers can only measure the composition of its outermost layers. While X-rays emitted by the superheated fronts of shockwaves in the remnants can reveal their composition to an extent, the limited spectral resolutions of current instruments makes them difficult to detect.

    In their study, Seitenzahl’s team exploited a new spectrometer that has recently been added to the VLT to study the remnants of a supernova at visible rather than X-ray wavelengths. The MUSE spectrometer combines high spectral resolution with a wide field-of-view, which makes it possible to acquire spectra at thousands of positions at the same time.

    ESO MUSE on the VLT on Yepun (UT4)

    The team used the spectrometer to search for visible wavelengths emitted by highly ionized states of iron and sulphur in the slocked, nonradiative remnants of three supernovae in the Large Magellanic Cloud. Though the light is extremely faint due to these transitions being optically forbidden, the VLT’s new setup had high enough spectral resolution to detect the characteristic transmission lines of several different ions.

    Seitenzahl and colleagues then used a new technique, dubbed “supernova remnant tomography”, to relate the Doppler shifts of the spectral lines to the velocities of supernova remnants at different positions. This allowed them to test previous models of supernova explosions, and their subsequent evolution, more rigorously than ever before.

    Their analysis revealed a clearly layered structure in one of the supernova remnants, with sulphur emission occurring in a region outside of one dominated by iron emissions. The team also found that one supernova appeared to have originated from a white dwarf with a lower mass than the Chandrasekhar limit. Though the dynamics of this event appeared consistent with current models, the observed spectral lines were less Doppler shifted than predicted.

    Seitenzahl’s team believe that this new technique represents an important advance in supernova analysis. They now aim to use observed their observed shifts in spectral lines to update current models of supernova formation and evolution.

    See the full article here .


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  • richardmitnick 12:15 pm on March 14, 2019 Permalink | Reply
    Tags: "A Cosmic Bat in Flight", , , , , , ESO Very Large Telescope (VLT), ESO’s Cosmic Gems programme, In 1864 John Herschel published the General Catalogue of Nebulae and Clusters, In 1888 John Louis Emil Dreyer published the New General Catalogue of Nebulae and Clusters of Stars (NGC)   

    From European Southern Observatory: “A Cosmic Bat in Flight” 

    ESO 50 Large

    From European Southern Observatory

    14 March 2019

    Calum Turner
    ESO Public Information Officer
    Garching bei München, Germany
    Tel: +49 89 3200 6670
    Email: pio@eso.org

    1
    Hidden in one of the darkest corners of the Orion constellation, this Cosmic Bat is spreading its hazy wings through interstellar space two thousand light-years away. It is illuminated by the young stars nestled in its core — despite being shrouded by opaque clouds of dust, their bright rays still illuminate the nebula. Too dim to be discerned by the naked eye, NGC 1788 reveals its soft colours to ESO’s Very Large Telescope in this image — the most detailed to date.

    ESO’s Very Large Telescope (VLT) has caught a glimpse of an ethereal nebula hidden away in the darkest corners of the constellation of Orion (The Hunter) — NGC 1788, nicknamed the Cosmic Bat. This bat-shaped reflection nebula doesn’t emit light — instead it is illuminated by a cluster of young stars in its core, only dimly visible through the clouds of dust. Scientific instruments have come a long way since NGC 1788 was first described, and this image taken by the VLT is the most detailed portrait of this nebula ever taken.

    Even though this ghostly nebula in Orion appears to be isolated from other cosmic objects, astronomers believe that it was shaped by powerful stellar winds from the massive stars beyond it. These streams of scorching plasma are thrown from a star’s upper atmosphere at incredible speeds, shaping the clouds secluding the Cosmic Bat’s nascent stars.

    NGC 1788 was first described by the German–British astronomer William Herschel, who included it in a catalogue that later served as the basis for one of the most significant collections of deep-sky objects, the New General Catalogue (NGC) [1]. A nice image of this small and dim nebula had already been captured by the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory, but this newly observed scene leaves it in the proverbial dust. Frozen in flight, the minute details of this Cosmic Bat’s dusty wings were imaged for the twentieth anniversary of one of ESO’s most versatile instruments, the FOcal Reducer and low dispersion Spectrograph 2 (FORS2).

    ESO FORS2 VLT mounted on Unit Telescope 1 (Antu)

    FORS2 is an instrument mounted on Antu, one of the VLT’s 8.2-metre Unit Telescopes at the Paranal Observatory, and its ability to image large areas of the sky in exceptional detail has made it a coveted member of ESO’s fleet of cutting-edge scientific instruments. Since its first light 20 years ago, FORS2 has become known as “the Swiss army knife of instruments”. This moniker originates from its uniquely broad set of functions [2]. FORS2’s versatility extends beyond purely scientific uses — its ability to capture beautiful high-quality images like this makes it a particularly useful tool for public outreach.

    This image was taken as part of ESO’s Cosmic Gems programme, an outreach initiative that uses ESO telescopes to produce images of interesting, intriguing or visually attractive objects for the purposes of education and public outreach. The programme makes use of telescope time that cannot be used for science observations, and — with the help of FORS2 — produces breathtaking images of some of the most striking objects in the night sky, such as this intricate reflection nebula. In case the data collected could be useful for future scientific purposes, these observations are saved and made available to astronomers through the ESO Science Archive.

    Notes

    [1] In 1864 John Herschel published the General Catalogue of Nebulae and Clusters, which built on extensive catalogues and contained entries for more than five thousand intriguing deep-sky objects. Twenty-four years later, this catalogue was expanded by John Louis Emil Dreyer and published as the New General Catalogue of Nebulae and Clusters of Stars (NGC), a comprehensive collection of stunning deep-sky objects.

    [2] In addition to being able to image large areas of the sky with precision, FORS2 can also measure the spectra of multiple objects in the night sky and analyse the polarisation of their light. Data from FORS2 are the basis of over 100 scientific studies published every year.

    Links

    NGC 1788 observed by the MPG/ESO 2.2-metre telescope
    ESO’s Cosmic Gems programme
    Images of the VLT

    See the full article here .


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    Please help promote STEM in your local schools.


    Stem Education Coalition

    Visit ESO in Social Media-

    Facebook

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    ESO Bloc Icon

    ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre EEuropean Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

    ESO La Silla HELIOS (HARPS Experiment for Light Integrated Over the Sun)

    ESO/HARPS at La Silla

    ESO 3.6m telescope & HARPS at Cerro LaSilla, Chile, 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO 2.2 meter telescope at La Silla, 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO/Cerro LaSilla, 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO VLT Platform at Cerro Paranal elevation 2,635 m (8,645 ft)


    ESO VLT 4 lasers on Yepun

    Glistening against the awesome backdrop of the night sky above ESO_s Paranal Observatory, four laser beams project out into the darkness from Unit Telescope 4 UT4 of the VLT.

    ESO/NTT at Cerro La Silla, Chile, at an altitude of 2400 metres



    ESO/Vista Telescope at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level

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

    ESO/E-ELT,to be on top of Cerro Armazones in the Atacama Desert of northern Chile. located at the summit of the mountain at an altitude of 3,060 metres (10,040 ft).

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

    Leiden MASCARA instrument, La Silla, located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    Leiden MASCARA cabinet at ESO Cerro la Silla located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    ESO Next Generation Transit Survey at Cerro Paranel, 2,635 metres (8,645 ft) above sea level


    ESO Speculoos telescopes four 1m-diameter robotic telescopes at ESO Paranal Observatory 2635 metres 8645 ft above sea level


    ESO TAROT telescope at Paranal, 2,635 metres (8,645 ft) above sea level

    ESO ExTrA telescopes at Cerro LaSilla at an altitude of 2400 metres

    A novel gamma ray telescope under construction on Mount Hopkins, Arizona. a large project known as the Cherenkov Telescope Array, composed of hundreds of similar telescopes to be situated in the Canary Islands and Chile. The telescope on Mount Hopkins will be fitted with a prototype high-speed camera, assembled at the University of Wisconsin–Madison, and capable of taking pictures at a billion frames per second. Credit: Vladimir Vassiliev

     
  • richardmitnick 12:12 pm on January 21, 2019 Permalink | Reply
    Tags: , , , , , ESO Very Large Telescope (VLT), , Making Stars When the Universe was Half Its Age, The Hubble Ultra Deep Field of galaxies   

    From Harvard-Smithsonian Center for Astrophysics: “Making Stars When the Universe was Half Its Age” 

    Harvard Smithsonian Center for Astrophysics


    From Harvard-Smithsonian Center for Astrophysics

    1
    The Hubble Ultra Deep Field of galaxies. A new study of the star formation activity in 179 of the galaxies in this image including many dating from about six billion years ago confirms an earlier puzzling result: lower mass galaxies tend to make stars at a rate slightly slower than expected. NASA, ESA, and S. Beckwith (STScI) and the HUDF Team.

    The universe is about 13.8 billion years old, and its stars are arguably its most momentous handiwork. Astronomers studying the intricacies of star formation across cosmic time are trying to understand whether stars and the processes that produce them were the same when the universe was younger, about half its current age. They already know that from three to six billion years after the big bang stars were being made at a rate roughly ten times faster than they are today. How this happened, and why, are some of the key questions being posed for the next decade of research.

    Star formation in a galaxy is thought to be triggered by the accretion of gas from the intergalactic medium (gas accretion via mergers between galaxies is thought to play a relatively minor role in the total numbers of stars produced). In galaxies that are actively making stars there is a tight relationship between their mass in stars and their rate of forming new stars, and this relationship approximately holds not only locally but even back when the universe was billions of years younger. In contrast, galaxies that are undergoing an active starburst – or the opposite, the quenching of star formation – fall above and below that relation respectively. The relationship supports the general picture of galaxy growth by gas accretion, except that for some reason smaller galaxies – those with fewer than about ten billion stars – seem to make slighter fewer stars than expected for their masses (the Milky Way is right at the turnover, with about ten billion stars and a rate of roughly one new star per year). A particularly significant consequence of this paucity, if real, is that simulations of galaxy growth do not show it, implying that the simulations are incorrect for smaller galaxies and that some physics is missing.

    CfA astronomer Sandro Tacchella is a member of a team that used the Multi Unit Spectroscopic Explorer instrument on the VLT (Very Large Telescope) to obtain optical spectra of galaxies in the famous Hubble Deep Field South image of galaxies.

    ESO MUSE on the VLT on Yepun (UT4)

    ESO VLT at Cerro Paranal in the Atacama Desert, •ANTU (UT1; The Sun ),
    •KUEYEN (UT2; The Moon ),
    •MELIPAL (UT3; The Southern Cross ), and
    •YEPUN (UT4; Venus – as evening star).
    elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo,

    They measured stellar emission lines in 179 distant galaxies in the field and used them to calculate the star formation behaviors after corrections for effects like dust extinction (which can make some of the optical lines appear weaker than they are). The find that the puzzle of depleted star formation in small galaxies is real at a level of roughly 5% even when accounting for noise and scatter in the data caused, for example, by galaxy evolution effects. The authors suggest that some kind of previously unaccounted for feedback may be responsible.

    Science paper:
    The MUSE Hubble Ultra Deep Field Survey XI. Constraining the low-mass end of the stellar mass – star formation rate relation at z < 1
    Astronomy and Astrophysics

    See the full article here .


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    Please help promote STEM in your local schools.

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    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.

     
  • richardmitnick 8:30 pm on July 26, 2018 Permalink | Reply
    Tags: , , , , , ESO Very Large Telescope (VLT), , , Reinhard Genzel,   

    From Max Planck Max Planck Institute for Extraterrestrial Physics: ” ‘The galactic centre offers fantastic opportunities’” 

    From Max Planck Max Planck Institute for Extraterrestrial Physics

    July 26, 2018

    Prof. Dr. Reinhard Genzel
    Max Planck Institute for Extraterrestrial Physics, Garching
    +49 89 30000-3280 genzel@mpe.mpg.de

    Helmut Hornung
    Administrative Headquarters of the Max Planck Society, München
    +49 89 2108-1404 hornung@gv.mpg.de

    It is highly likely that there is a black hole at the centre of the Milky Way. The astronomers working under Reinhard Genzel, Director of the Max Planck Institute for Extraterrestrial Physics in Garching near Munich are making repeated detailed studies of the surrounding area of the gravitational trap. Now, the researchers have succeeded in making a huge achievement in the art of observation: from the motion of a star called S2 around the black hole, which is 26,000 light years away, they have measured an effect predicted by Albert Einstein known as the gravitational redshift. What is so special about this observation?

    Star S2 Keck/UCLA Galactic Center Group

    1
    The astronomer and his tool: Reinhard Genzel, Director at the Max Planck Institute for Extraterrestrial Physics, in front of the Very Large Telescope, which he uses to peer into the heart of the Milky Way.
    © MPE

    ESO VLT at Cerro Paranal in the Atacama Desert, elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo

    You have been studying the surrounding area of the black hole in the centre of the Milky Way for more than 20 years. Were you specifically looking for the gravitational redshift that you have now discovered, or did this happen by accident?

    No, the discovery was by no means accidental. We’ve been systematically looking for this and preparing the experiment for ten years now. We’ve known for a long time that the object in the galactic centre has a very high mass, and that it is highly plausible that it is a black hole. However, there’s a difference between plausibility and physical certainty. That’s why we design all kinds of tests, for which the centre of our Milky Way offers wonderful opportunities. In short: our current measurement of the gravitational redshift is already providing very strong evidence of the existence of the black hole in the galactic centre – and of the general theory of relativity.

    The current observations are taking place on the margins of what is measurable. What instruments did you need in order to achieve your successful result?

    Certainly, measurements like these would not have been possible just a few years ago. At that time, we observed the centre of the Milky Way using a single eight-meter mirror in the Very Large Telescope. Now, we us all four telescopes in the system in Chile at the same time by using interferometry.

    ESO VLT Interferometer, at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level

    In radio astronomy, this procedure, in which the waves of an object overlap and this appears sharper as a result, has already been established for decades, but not in the field of optics. For this reason, the Max Planck Institute for Extraterrestrial Physics headed by Frank Eisenhauer, together with the Max Planck Institute for Astronomy, the European Southern Observatory, the University of Cologne, two French CNRS institutes and institutes in Porto and Lisbon, has developed a highly complex instrument called Gravity.

    ESO GRAVITY in the VLTI

    Gravity processes the signals of the four individual telescopes and offers a huge improvement in the detail resolution in the infrared range. This means that thanks to Gravity, the Very Large Telescope could in theory provide images of two adjacent two-euro coins on the moon. It’s no exaggeration to say that Gravity has led to a breakthrough in the field of optics in matters relating to interferometry.

    A key role during observation is probably also played by adaptive optics. What’s the reason for this?

    Glistening against the awesome backdrop of the night sky above ESO_s Paranal Observatory, four laser beams project out into the darkness from Unit Telescope 4 UT4 of the VLT.

    Turbulences in the Earth’s atmosphere distort the wavefronts of the stars’ light. In principle, the aim is to compensate the crests and troughs of waves. This is made possible through the use of a mirror in the telescope, which has mechanical tappets attached to its rear side. These so-called actuators deform the surface of this small mirror in the beam path up to a thousand times per second, and in this way eliminate the distortions. In this way, we achieve the theoretical resolution of the telescope – and this is higher by a factor of ten than those that are achieved without correcting the air turbulence.

    You said that the centre of the Milky Way offers wonderful opportunities to finally put the general theory of relativity to the test …

    … and the redshift measured by us is one of these tests. In this regard, it’s important to realise that such a redshift is not just caused by the Doppler effect. We know this from everyday life when for example an ambulance drives past us, and the tone level of the siren increases and decreases. At the same time, this means a displacement of the wavelength into the short- or long-wave range. This also occurs with light waves, where reference is made to blueshift or also redshift. This aside, according to the general theory of relativity, a redshift also occurs in the field of gravity when light moves there and fights against it to a certain degree. This effect also has an impact on the radiation of the S2 star, which approaches the black hole up to a distance of around 14 billion kilometres – which is the equivalent of three times the distance between the planet Neptune and the Sun. On 19 May of this year, S2 again passed the place where the distance was lowest during its orbit. For us, this offered a unique opportunity to measure the gravitational redshift.

    Can you foresee conducting further tests for the general theory of relativity?

    Yes, another test would be the Schwarzschild precession. This sounds complicated, but in fact, it’s simple. According to the general theory of relativity, celestial bodies that move around a central mass do not run on closed trajectories. The point of the greatest approximation, the perihelion, constantly continues to move in space. This can be clearly observed with planet Mercury, the perihelion rotation of which has been known for a long time. Its measured value correlates precisely with Einstein’s prediction. It is likely that a similar effect can be observed in the orbits of stars that move around the central black hole of the Milky Way. Indeed, we are already seeing the first signs of this. In two years’ time, we should then have statistically significant measurements. The best test for the general theory of relativity would otherwise be when a star falls into the black hole in front of our eyes. Unfortunately, statistically speaking, this happens only once every 10,000 years.

    The gravitation effect measured by your group is a wonderful piece of evidence supporting Einstein’s theory of relativity. Is there any doubt at all now about the validity of this theory?

    Yes, certainly! To put it in drastic terms: the physical laws known to us to date only apply to a limited range of parameters. The tiniest and the largest in particular, namely quantum physics and the theory of relativity, do not match each other. And so far, a corresponding quantum theory of gravitation has not yet been developed.

    Interview: Helmut Hornung

    See the full article here .

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    Stem Education Coalition

    For their astrophysical research, the MPE scientists measure the radiation of far away objects in different wavelenths areas: from millimetere/sub-millimetre and infared all the way to X-ray and gamma-ray wavelengths. These methods span more than twelve decades of the electromagnetic spectrum.

    The research topics pursued at MPE range from the physics of cosmic plasmas and of stars to the physics and chemistry of interstellar matter, from star formation and nucleosynthesis to extragalactic astrophysics and cosmology. The interaction with observers and experimentalists in the institute not only leads to better consolidated efforts but also helps to identify new, promising research areas early on.

    The structural development of the institute mainly has been directed by the desire to work on cutting-edge experimental, astrophysical topics using instruments developed in-house. This includes individual detectors, spectrometers and cameras but also telescopes and integrated, complete payloads. Therefore the engineering and workshop areas are especially important for the close interlink between scientific and technical aspects.

    The scientific work is done in four major research areas that are supervised by one of the directors:

    Center for Astrochemical Studies (CAS)
    Director: P. Caselli

    High-Energy Astrophysics
    Director: P. Nandra

    Infrared/Submillimeter Astronomy
    Director: R. Genzel

    Optical & Interpretative Astronomy
    Director: R. Bender

    Within these areas scientists lead individual experiments and research projects organised in about 25 project teams.

    The Max Planck Society is Germany’s most successful research organization. Since its establishment in 1948, no fewer than 18 Nobel laureates have emerged from the ranks of its scientists, putting it on a par with the best and most prestigious research institutions worldwide. The more than 15,000 publications each year in internationally renowned scientific journals are proof of the outstanding research work conducted at Max Planck Institutes – and many of those articles are among the most-cited publications in the relevant field.

    What is the basis of this success? The scientific attractiveness of the Max Planck Society is based on its understanding of research: Max Planck Institutes are built up solely around the world’s leading researchers. They themselves define their research subjects and are given the best working conditions, as well as free reign in selecting their staff. This is the core of the Harnack principle, which dates back to Adolph von Harnack, the first president of the Kaiser Wilhelm Society, which was established in 1911. This principle has been successfully applied for nearly one hundred years. The Max Planck Society continues the tradition of its predecessor institution with this structural principle of the person-centered research organization.

    The currently 83 Max Planck Institutes and facilities conduct basic research in the service of the general public in the natural sciences, life sciences, social sciences, and the humanities. Max Planck Institutes focus on research fields that are particularly innovative, or that are especially demanding in terms of funding or time requirements. And their research spectrum is continually evolving: new institutes are established to find answers to seminal, forward-looking scientific questions, while others are closed when, for example, their research field has been widely established at universities. This continuous renewal preserves the scope the Max Planck Society needs to react quickly to pioneering scientific developments.

     
  • richardmitnick 8:54 am on May 27, 2018 Permalink | Reply
    Tags: , , , , ESO Very Large Telescope (VLT), ESO’s Very Large Telescope Celebrates 20 Years of Remarkable Science   

    From European Southern Observatory: “ESO’s Very Large Telescope Celebrates 20 Years of Remarkable Science” 

    ESO 50 Large

    From European Southern Observatory

    25 May 2018
    Richard Hook
    ESO Public Information Officer
    Garching bei München, Germany
    Tel: +49 89 3200 6655
    Cell: +49 151 1537 3591
    Email: pio@eso.org

    1

    ESO’s Very Large Telescope, the flagship facility for European ground-based astronomy, celebrates its 20th anniversary today. The first of the VLT’s Unit Telescopes saw first light on 25 May 1998, ushering in a new era of astronomy. Over the following years three more 8.2-metre Unit Telescopes were completed and these giants were joined by the four smaller Auxiliary Telescopes (ATs) that form part of the VLT Interferometer. The interferometer first combined the light from two ATs in 2005, creating a virtual telescope up to 200 metres in diameter that now regularly observes the surfaces of stars.

    The VLT could not function without its world-class suite of instruments, which have been developed in collaboration with astronomers and engineers in the ESO community. A spectacular recent addition to the VLT is the 4 Laser Guide Star Facility, which projects four 22-watt laser beams into the upper atmosphere to create artificial stars that help correct for the effects of atmospheric turbulence, a technique known as adaptive optics [see the great image below].

    The instruments on the VLT are in high demand — last year the requested observing time exceeded the available time by a factor of five. Successful observing requests have provided the data behind thousands of peer-reviewed scientific papers — in 2017 alone, over 600 papers were published using data from the VLT.

    ESO’s flagship observatory has not just led to a great quantity of science, but also quality. The VLT has contributed to breakthroughs in many areas of astronomy, and is responsible for seven of ESO’s Top 10 Astronomical Discoveries.

    For instance, in 2009 the VLT overcame the demanding observational challenge of imaging a planet around another star for the first time, followed by the first analysis of the atmosphere around a super-Earth exoplanet in 2010. ESO has continued to build on this planet-hunting capability with SPHERE, a planet-hunting instrument that was added to the VLT in 2014.

    ESO SPHERE extreme adaptive optics system and coronagraphic facility on the extreme adaptive optics system and coronagraphic facility on the VLT, Cerro Paranal, Chile, with an elevation of 2,635 metres (8,645 ft) above sea level


    ESO/SPHERE extreme adaptive optics system and coronagraphic facility on the VLT, Cerro Paranal, Chile, with an elevation of 2,635 metres (8,645 ft) above sea level

    Painstaking VLT observations spanning nearly two decades revealed the motions of stars orbiting the supermassive black hole at the centre of our galaxy.

    Sgr A* from ESO VLT

    This continues to be a closely-studied topic — in fact, this week the VLT is scrutinising the star S2 as it passes close by this hidden monster. Just last year ESO’s fleet of telescopes, including the VLT, was used to observe another exotic phenomenon: the first light from a gravitational wave source.

    On top of its scientific legacy, the VLT is also playing a vital role in preparing technology for ESO’s Extremely Large Telescope (ELT), currently under construction 23 kilometres from the VLT in the Atacama Desert in northern Chile. ESO’s experience in building and operating remote, cutting-edge observatories such as the VLT is proving vital in developing the ELT, the next frontier in ground-based astronomy.

    See the full article here .


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    stem

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    ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

    ESO La Silla HELIOS (HARPS Experiment for Light Integrated Over the Sun)

    ESO 3.6m telescope & HARPS at Cerro LaSilla, Chile, 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO 2.2 meter telescope at La Silla, 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO/Cerro LaSilla, 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO VLT Platform at Cerro Paranal elevation 2,635 m (8,645 ft)

    ESO/Vista Telescope at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level

    Glistening against the awesome backdrop of the night sky above ESO_s Paranal Observatory, four laser beams project out into the darkness from Unit Telescope 4 UT4 of the VLT.

    ESO/NTT at Cerro La Silla, Chile, at an altitude of 2400 metres

    ESO/Vista Telescope at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level

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

    ESO/E-ELT,to be on top of Cerro Armazones in the Atacama Desert of northern Chile, at an altitude 3,046 m (9,993 ft)

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

    Leiden MASCARA instrument, La Silla, located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    Leiden MASCARA cabinet at ESO Cerro la Silla located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    ESO Next Generation Transit Survey at Cerro Paranel, 2,635 metres (8,645 ft) above sea level

    SPECULOOS four 1m-diameter robotic telescopes 2016 in the ESO Paranal Observatory, 2,635 metres (8,645 ft) above sea level

    ESO TAROT telescope at Paranal, 2,635 metres (8,645 ft) above sea level

    ESO ExTrA telescopes at Cerro LaSilla at an altitude of 2400 metres

     
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