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  • richardmitnick 12:34 am on April 15, 2021 Permalink | Reply
    Tags: "Telescopes Unite in Unprecedented Observations of Famous Black Hole", Black hole Messier 87*, Event Horizon Telescope Array,   

    From Harvard-Smithsonian Center for Astrophysics (US): “Telescopes Unite in Unprecedented Observations of Famous Black Hole” 

    From Harvard-Smithsonian Center for Astrophysics (US)


    Media contacts:
    Peter Edmonds
    Chandra X-ray Center, Cambridge, Mass.

    Molly Porter
    Marshall Space Flight Center, Huntsville, Alabama

    Credit: EHT Collaboration.

    In April 2019, scientists released the first image of a black hole in galaxy Messier 87 using the Event Horizon Telescope (EHT).

    Event Horizon Telescope Array

    Arizona Radio Observatory.

    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).


    Combined Array for Research in Millimeter-wave Astronomy (CARMA Array for Research in Millimeter-wave Astronomy(US)), in the Inyo Mountains to the east of the California Institute of Technology Owens Valley Radio Observatory(US), at a site called Cedar Flat, Altitude 1,222 m (4,009 ft), relocated to Owens Valley Radio Observatory, Altitude 1,222 m (4,009 ft).


    National Astronomy Observatory of Japan(JP) Atacama Submillimeter Telescope Experiment (ASTE) deployed to its site on Pampa La Bola, near Cerro Chajnantor and the Llano de Chajnantor, Observatory in northern Chile, Altitude 4,800 m (15,700 ft).

    NAOJ Atacama Submillimeter Telescope Experiment (ASTE).

    CfA Submillimeter Observatory(US) on MaunaKea, Hawaii, USA, Altitude 4,205 m (13,796 ft).

    CfA Submillimeter Observatory.

    Greenland Telescope.

    Institute of Radio Astronomy [Institut de Radioastronomie Millimétrique](ES) 30m Radio telescope, on Pico Veleta in the Spanish Sierra Nevada, Altitude 2,850 m (9,350 ft).

    (IRAM) 30m.

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

    IRAM NOEMA, France.

    James Clerk Maxwell Telescope.

    The University of Massachusetts Amherst and Mexico’s Instituto Nacional de Astrofísica, Óptica y Electrónica
    LMT – Large Millimeter Telescope Alfonso Serrano(MX), Mexico, at an altitude of 4850 meters on top of the Sierra Negra.

    Large Millimeter Telescope Alfonso Serrano.


    South Pole Telescope SPTPOL. The SPT collaboration is made up of over a dozen (mostly North American) institutions, including the University of Chicago; the University of California, Berkeley; Case Western Reserve University; Harvard/Smithsonian Astrophysical Observatory; the University of Colorado, Boulder; McGill(CA) University, The University of Illinois, Urbana-Champaign: University of California, Davis; Ludwig Maximilians Universität München(DE); Argonne National Laboratory; and the National Institute for Standards and Technology. It is funded by the National Science Foundation(US).

    Future Array/Telescopes

    California Institute of Technology Owens Valley Radio Observatory(US), located near Big Pine, California (US) in Owens Valley, Altitude1,222 m (4,009 ft).

    Caltech Owens Valley Radio Observatory.

    However, that remarkable achievement was just the beginning of the science story to be told.

    Data from 19 observatories released today promise to give unparalleled insight into this black hole and the system it powers, and to improve tests of Einstein’s General Theory of Relativity.

    “We knew that the first direct image of a black hole would be groundbreaking,” says Kazuhiro Hada of the National Astronomical Observatory of Japan [国立天文台](JP), a co-author of a new study published in The Astrophysical Journal Letters that describes the large set of data. “But to get the most out of this remarkable image, we need to know everything we can about the black hole’s behavior at that time by observing over the entire electromagnetic spectrum.”

    The immense gravitational pull of a supermassive black hole can power jets of particles that travel at almost the speed of light across vast distances. Messier 87*’s jets produce light spanning the entire electromagnetic spectrum, from radio waves to visible light to gamma rays. This pattern is different for each black hole. Identifying this pattern gives crucial insight into a black hole’s properties—for example, its spin and energy output—but is a challenge because the pattern changes with time.

    Scientists compensated for this variability by coordinating observations with many of the world’s most powerful telescopes on the ground and in space, collecting light from across the spectrum. These 2017 observations were the largest simultaneous observing campaign ever undertaken on a supermassive black hole with jets.

    Three observatories managed by the Center for Astrophysics | Harvard & Smithsonian participated in the landmark campaign: the Submillimeter Array (SMA) in Hilo, Hawaii; the space-based Chandra X-ray Observatory; and the Very Energetic Radiation Imaging Telescope Array System (VERITAS) in southern Arizona.

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

    Beginning with the EHT’s now iconic image of Messier 87*, a new video takes viewers on a journey through the data from each telescope. Each consecutive frame shows data across many factors of ten in scale, both of wavelengths of light and physical size.

    The sequence begins with the April 2019 image of the black hole. It then moves through images from other radio telescope arrays from around the globe (SMA), moving outward in the field of view during each step. Next, the view changes to telescopes that detect visible light, ultraviolet light, and X-rays (Chandra). The screen splits to show how these images, which cover the same amount of the sky at the same time, compare to one another. The sequence finishes by showing what gamma-ray telescopes on the ground (VERITAS), and Fermi in space, detect from this black hole and its jet.

    Each telescope delivers different information about the behavior and impact of the 6.5-billion-solar-mass black hole at the center of Messier 87*, which is located about 55 million light-years from Earth.

    “There are multiple groups eager to see if their models are a match for these rich observations, and we’re excited to see the whole community use this public data set to help us better understand the deep links between black holes and their jets,” says co-author Daryl Haggard of McGill University in Montreal, Canada.

    The data were collected by a team of 760 scientists and engineers from nearly 200 institutions, spanning 32 countries or regions, and using observatories funded by agencies and institutions around the globe. The observations were concentrated from the end of March to the middle of April 2017.

    “This incredible set of observations includes many of the world’s best telescopes,” says co-author Juan Carlos Algaba of the University of Malaya [Universiti Malaya] (MY) in Kuala Lumpur, Malaysia. “This is a wonderful example of astronomers around the world working together in the pursuit of science.”

    Additional Information

    The Astrophysical Journal Letter describing these results is available here. This paper was led by 33 members of the EHT Multiwavelength Science Working Group, and includes as coauthors members of the following collaborations: the entire Event Horizon Telescope Collaboration; the Fermi Large Area Telescope Collaboration; the H.E.S.S collaboration; the MAGIC collaboration; the VERITAS collaboration and the EAVN collaboration. The coordinators of the EHT Multiwavelength Science Working Group are Sera Markoff, Kazuhiro Hada, and Daryl Haggard, who together with Juan Carlos Algaba and Mislav Baloković, also coordinated work on the paper.

    Partner MWL facilities include: European VLBI Network ; National Radio Astronomy Observatory(US) High Sensitivity Array ; VLBI Exploration of Radio Astrometry; Korea Astronomy and Space Science Institute [한국천문연구원] (KR); East Asian VLBI Network/KVN and VERA Array ; NRAO Very Long Baseline Array (US); Global Millimeter VLBI Array ; ESO Very Large Telescope Interferometer GRAVITY Instrument (VLTI/GRAVITY); Neil Gehrels Swift Observatory (Swift); Hubble Space Telescope (HST); Chandra X-ray Observatory (Chandra); Nuclear Spectroscopic Telescope Array (NuSTAR); High Throughput X-ray Spectroscopy Mission and X-ray Multi-Mirror Mission (XMM-Newton); Fermi Large Area Space Telescope (Fermi-LAT) [above]; High Energy Stereoscopic System (H.E.S.S.) [above]; Major Atmospheric Gamma Imaging Cherenkov Telescopes (MAGIC) [above]; Very Energetic Radiation Imaging Telescope Array System (VERITAS) [above].

    The 2017 campaign involved a large number of observatories and telescopes [all cited elsewhere in this article dexcept those cited here]. At radio wavelengths it involved: the European Very Long Baseline Interferometry (VLBI) Network (EVN) on May 9, 2017; the High Sensitivity Array (HSA), which includes the Very Large Array (VLA), the MPIFR Effelsberg 100m antenna and the 10 stations of the National Radio Astronomy Observatory (NRAO) Very Long Baseline Array (VLBA) on May 15, 16 and 20; the VLBI Exploration of Radio Astronomy (VERA) over 17 different times in 2017; the Korean VLBI Network (KVN) over seven epochs between March and December; the East Asian VLBI Network (EAVN) and the KVN and VERA Array (KaVA) , over 14 epochs between March and May 2017; the VLBA on May 5, 2017; the Global Millimeter-VLBI-Array (GMVA) on March 30, 2017; the Atacama Large Millimeter/submillimeter Array (ALMA); the Submillimeter Array (SMA) as part of an ongoing monitoring program. At ultraviolet (UV) wavelengths it involved the Neil Gehrels Swift Observatory (Swift) with multiple observations between March 22 and April 20, 2017; and at optical wavelengths: Swift; and the Hubble Space Telescope on April 7, 12, and 17, 2017. (The Hubble data were retrieved from the Hubble archive because it was part of an independent observing program.) At X-ray wavelengths it involved the Chandra X-ray Observatory on April 11 and 14, 2017; the Nuclear Spectroscopic Telescope Array (NuSTAR) on April 11 and 14, 2017; and Swift. At gamma-ray wavelengths it involved Fermi from March 22 to April 20, 2017; the High Energy Stereoscopic System (H.E.S.S); the Major Atmospheric Gamma Imaging Cherenkov (MAGIC) telescopes, and the Very Energetic Radiation Imaging Telescope Array System (VERITAS).

    The EHT Multi-wavelength (MWL) Working Group is a collective of EHT Collaboration members and external partners working together to ensure broadband MWL coverage during EHT campaigns, to maximize science output. The EHT collaboration involves more than 300 researchers from Africa, Asia, Europe, North and South America. The international collaboration is working to capture the most detailed black hole images ever obtained by creating a virtual Earth-sized telescope. Supported by considerable international investment, the EHT links existing telescopes using novel systems — creating a fundamentally new instrument with the highest angular resolving power that has yet been achieved.

    The individual EHT telescopes [see the full EHT enumeration above] involved are: ALMA, APEX, the IRAM 30-meter Telescope, the James Clerk Maxwell Telescope (JCMT), the Large Millimeter Telescope (LMT), the Submillimeter Array (SMA), the Submillimeter Telescope (SMT), and the South Pole Telescope (SPT). The Greenland Telescope, the Kitt Peak Telescope, and NOEMA joined EHT after the 2017 observations.

    Partner MWL facilities include: European VLBI Network (EVN); High Sensitivity Array (HSA); VLBI Exploration of Radio Astrometry (VERA); Korea VLBI Network (KVN); East Asian VLBI Network/KVN and VERA Array (EAVN/KaVA); Very Long Baseline Array (VLBA); Global Millimeter VLBI Array (GMVA); Very Large Telescope Interferometer GRAVITY Instrument (VLTI/GRAVITY); Neil Gehrels Swift Observatory (Swift); Hubble Space Telescope (HST); Chandra X-ray Observatory (Chandra); Nuclear Spectroscopic Telescope Array (NuSTAR); High Throughput X-ray Spectroscopy Mission and X-ray Multi-Mirror Mission (XMM-Newton); Fermi Large Area Space Telescope (Fermi-LAT); High Energy Stereoscopic System (H.E.S.S.); Major Atmospheric Gamma Imaging Cherenkov Telescopes (MAGIC); and the Very Energetic Radiation Imaging Telescope Array System (VERITAS).

    See the full article here .

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Harvard-Smithsonian Center for Astrophysics (US) combines the resources and research facilities of the Harvard College Observatory(US) and the Smithsonian Astrophysical Observatory(US) 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(US) is a bureau of the Smithsonian Institution(US), founded in 1890. The Harvard College Observatory, founded in 1839, is a research institution of the Faculty of Arts and Sciences, Harvard University(US), and provides facilities and substantial other support for teaching activities of the Department of Astronomy.

    Founded in 1973 and headquartered in Cambridge, Massachusetts, the CfA leads a broad program of research in astronomy, astrophysics, Earth and space sciences, as well as science education. The CfA either leads or participates in the development and operations of more than fifteen ground- and space-based astronomical research observatories across the electromagnetic spectrum, including the forthcoming Giant Magellan Telescope(CL) and the Chandra X-ray Observatory(US), one of NASA’s Great Observatories.


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

    Hosting more than 850 scientists, engineers, and support staff, the CfA is among the largest astronomical research institutes in the world. Its projects have included Nobel Prize-winning advances in cosmology and high energy astrophysics, the discovery of many exoplanets, and the first image of a black hole. The CfA also serves a major role in the global astrophysics research community: the CfA’s Astrophysics Data System(ADS)(US), for example, has been universally adopted as the world’s online database of astronomy and physics papers. Known for most of its history as the “Harvard-Smithsonian Center for Astrophysics”, the CfA rebranded in 2018 to its current name in an effort to reflect its unique status as a joint collaboration between Harvard University and the Smithsonian Institution. The CfA’s current Director (since 2004) is Charles R. Alcock, who succeeds Irwin I. Shapiro (Director from 1982 to 2004) and George B. Field (Director from 1973 to 1982).

    The Center for Astrophysics | Harvard & Smithsonian is not formally an independent legal organization, but rather an institutional entity operated under a Memorandum of Understanding between Harvard University (US) and the Smithsonian Institution (US). This collaboration was formalized on July 1, 1973, with the goal of coordinating the related research activities of the Harvard College Observatory (US) (HCO) and the Smithsonian Astrophysical Observatory (US) under the leadership of a single Director, and housed within the same complex of buildings on the Harvard campus in Cambridge, Massachusetts. The CfA’s history is therefore also that of the two fully independent organizations that comprise it. With a combined lifetime of more than 300 years, HCO and SAO have been host to major milestones in astronomical history that predate the CfA’s founding.

    History of the Smithsonian Astrophysical Observatory (SAO)

    Samuel Pierpont Langley, the third Secretary of the Smithsonian, founded the Smithsonian Astrophysical Observatory on the south yard of the Smithsonian Castle (on the U.S. National Mall) on March 1,1890. The Astrophysical Observatory’s initial, primary purpose was to “record the amount and character of the Sun’s heat”. Charles Greeley Abbot was named SAO’s first director, and the observatory operated solar telescopes to take daily measurements of the Sun’s intensity in different regions of the optical electromagnetic spectrum. In doing so, the observatory enabled Abbot to make critical refinements to the Solar constant, as well as to serendipitously discover Solar variability. It is likely that SAO’s early history as a solar observatory was part of the inspiration behind the Smithsonian’s “sunburst” logo, designed in 1965 by Crimilda Pontes.

    In 1955, the scientific headquarters of SAO moved from Washington, D.C. to Cambridge, Massachusetts to affiliate with the Harvard College Observatory (HCO). Fred Lawrence Whipple, then the chairman of the Harvard Astronomy Department, was named the new director of SAO. The collaborative relationship between SAO and HCO therefore predates the official creation of the CfA by 18 years. SAO’s move to Harvard’s campus also resulted in a rapid expansion of its research program. Following the launch of Sputnik (the world’s first human-made satellite) in 1957, SAO accepted a national challenge to create a worldwide satellite-tracking network, collaborating with the United States Air Force on Project Space Track.

    With the creation of National Aeronautics and Space Administration(US) the following year and throughout the space race, SAO led major efforts in the development of orbiting observatories and large ground-based telescopes, laboratory and theoretical astrophysics, as well as the application of computers to astrophysical problems.

    History of Harvard College Observatory (HCO)

    Partly in response to renewed public interest in astronomy following the 1835 return of Halley’s Comet, the Harvard College Observatory was founded in 1839, when the Harvard Corporation appointed William Cranch Bond as an “Astronomical Observer to the University”. For its first four years of operation, the observatory was situated at the Dana-Palmer House (where Bond also resided) near Harvard Yard, and consisted of little more than three small telescopes and an astronomical clock. In his 1840 book recounting the history of the college, then Harvard President Josiah Quincy III noted that “…there is wanted a reflecting telescope equatorially mounted…”. This telescope, the 15-inch “Great Refractor”, opened seven years later (in 1847) at the top of Observatory Hill in Cambridge (where it still exists today, housed in the oldest of the CfA’s complex of buildings). The telescope was the largest in the United States from 1847 until 1867. William Bond and pioneer photographer John Adams Whipple used the Great Refractor to produce the first clear Daguerrotypes of the Moon (winning them an award at the 1851 Great Exhibition in London). Bond and his son, George Phillips Bond (the second Director of HCO), used it to discover Saturn’s 8th moon, Hyperion (which was also independently discovered by William Lassell).

    Under the directorship of Edward Charles Pickering from 1877 to 1919, the observatory became the world’s major producer of stellar spectra and magnitudes, established an observing station in Peru, and applied mass-production methods to the analysis of data. It was during this time that HCO became host to a series of major discoveries in astronomical history, powered by the Observatory’s so-called “Computers” (women hired by Pickering as skilled workers to process astronomical data). These “Computers” included Williamina Fleming; Annie Jump Cannon; Henrietta Swan Leavitt; Florence Cushman; and Antonia Maury, all widely recognized today as major figures in scientific history. Henrietta Swan Leavitt, for example, discovered the so-called period-luminosity relation for Classical Cepheid variable stars, establishing the first major “standard candle” with which to measure the distance to galaxies. Now called “Leavitt’s Law”, the discovery is regarded as one of the most foundational and important in the history of astronomy; astronomers like Edwin Hubble, for example, would later use Leavitt’s Law to establish that the Universe is expanding, the primary piece of evidence for the Big Bang model.

    Upon Pickering’s retirement in 1921, the Directorship of HCO fell to Harlow Shapley (a major participant in the so-called “Great Debate” of 1920). This era of the observatory was made famous by the work of Cecelia Payne-Gaposchkin, who became the first woman to earn a Ph.D. in astronomy from Radcliffe College (a short walk from the Observatory). Payne-Gapochkin’s 1925 thesis proposed that stars were composed primarily of hydrogen and helium, an idea thought ridiculous at the time. Between Shapley’s tenure and the formation of the CfA, the observatory was directed by Donald H. Menzel and then Leo Goldberg, both of whom maintained widely recognized programs in solar and stellar astrophysics. Menzel played a major role in encouraging the Smithsonian Astrophysical Observatory to move to Cambridge and collaborate more closely with HCO.

    Joint history as the Center for Astrophysics (CfA)

    The collaborative foundation for what would ultimately give rise to the Center for Astrophysics began with SAO’s move to Cambridge in 1955. Fred Whipple, who was already chair of the Harvard Astronomy Department (housed within HCO since 1931), was named SAO’s new director at the start of this new era; an early test of the model for a unified Directorship across HCO and SAO. The following 18 years would see the two independent entities merge ever closer together, operating effectively (but informally) as one large research center.

    This joint relationship was formalized as the new Harvard–Smithsonian Center for Astrophysics on July 1, 1973. George B. Field, then affiliated with UC Berkeley(US), was appointed as its first Director. That same year, a new astronomical journal, the CfA Preprint Series was created, and a CfA/SAO instrument flying aboard Skylab discovered coronal holes on the Sun. The founding of the CfA also coincided with the birth of X-ray astronomy as a new, major field that was largely dominated by CfA scientists in its early years. Riccardo Giacconi, regarded as the “father of X-ray astronomy”, founded the High Energy Astrophysics Division within the new CfA by moving most of his research group (then at American Sciences and Engineering) to SAO in 1973. That group would later go on to launch the Einstein Observatory (the first imaging X-ray telescope) in 1976, and ultimately lead the proposals and development of what would become the Chandra X-ray Observatory. Chandra, the second of NASA’s Great Observatories and still the most powerful X-ray telescope in history, continues operations today as part of the CfA’s Chandra X-ray Center. Giacconi would later win the 2002 Nobel Prize in Physics for his foundational work in X-ray astronomy.

    Shortly after the launch of the Einstein Observatory, the CfA’s Steven Weinberg won the 1979 Nobel Prize in Physics for his work on electroweak unification. The following decade saw the start of the landmark CfA Redshift Survey (the first attempt to map the large scale structure of the Universe), as well as the release of the Field Report, a highly influential Astronomy & Astrophysics Decadal Survey chaired by the outgoing CfA Director George Field. He would be replaced in 1982 by Irwin Shapiro, who during his tenure as Director (1982 to 2004) oversaw the expansion of the CfA’s observing facilities around the world, including the newly named Fred Lawrence Whipple Observatory(US), the Infrared Telescope (IRT) aboard the Space Shuttle, the 6.5-meter Multiple Mirror Telescope(US), the NASA SOHO satellite(US), and the launch of Chandra [above] in 1999.

    CfA Fred Lawrence Whipple Observatory(US) , located near Amado, Arizona on the slopes of Mount Hopkins, Altitude 2,606 m (8,550 ft)

    Multi-Mirror Telescope

    the 6.5-meter Multiple Mirror Telescope(US) at Arizona Fred Lawrence Whipple Observatory at the summit of Mount Hopkins near Tucson, Arizona, USA, Altitude 2,616 m (8,583 ft) n the Santa Rita Mountains.

    CfA-led discoveries throughout this period include canonical work on Supernova 1987A, the “CfA2 Great Wall” (then the largest known coherent structure in the Universe), the best-yet evidence for supermassive black holes, and the first convincing evidence for an extrasolar planet.

    The 1990s also saw the CfA unwittingly play a major role in the history of computer science and the internet: in 1990, SAO developed SAOImage, one of the world’s first X11-based applications made publicly available (its successor, DS9, remains the most widely used astronomical FITS image viewer worldwide). During this time, scientists at the CfA also began work on what would become the Astrophysics Data System (ADS), one of the world’s first online databases of research papers. By 1993, the ADS was running the first routine transatlantic queries between databases, a foundational aspect of the internet today.

    The CfA Today

    Research at the CfA

    Charles Alcock, known for a number of major works related to massive compact halo objects, was named the third director of the CfA in 2004. Today Alcock overseas one of the largest and most productive astronomical institutes in the world, with more than 850 staff and an annual budget in excess of $100M. The Harvard Department of Astronomy, housed within the CfA, maintains a continual complement of approximately 60 Ph.D. students, more than 100 postdoctoral researchers, and roughly 25 undergraduate majors in astronomy and astrophysics from Harvard College. SAO, meanwhile, hosts a long-running and highly rated REU Summer Intern program as well as many visiting graduate students. The CfA estimates that roughly 10% of the professional astrophysics community in the United States spent at least a portion of their career or education there.

    The CfA is either a lead or major partner in the operations of the Fred Lawrence Whipple Observatory, the Submillimeter Array, MMT Observatory, the South Pole Telescope, VERITAS, and a number of other smaller ground-based telescopes. The CfA’s 2019-2024 Strategic Plan includes the construction of the Giant Magellan Telescope as a driving priority for the Center.

    CfA Submillimeter Array, Mauna Kea, Hawaii, USA, Altitude 4,080 m (13,390 ft).

    South Pole Telescope SPTPOL. The SPT collaboration is made up of over a dozen (mostly North American) institutions, including the University of Chicago; the University of California, Berkeley; Case Western Reserve University; Harvard/Smithsonian Astrophysical Observatory; the University of Colorado, Boulder; McGill(CA) University, The University of Illinois, Urbana-Champaign: University of California, Davis; Ludwig Maximilians Universität München(DE); Argonne National Laboratory; and the National Institute for Standards and Technology. It is funded by the National Science Foundation(US).

    Along with the Chandra X-ray Observatory, the CfA plays a central role in a number of space-based observing facilities, including the recently launched Parker Solar Probe, Kepler Space Telescope, the Solar Dynamics Observatory (SDO), and HINODE. The CfA, via the Smithsonian Astrophysical Observatory, recently played a major role in the Lynx X-ray Observatory, a NASA-Funded Large Mission Concept Study commissioned as part of the 2020 Decadal Survey on Astronomy and Astrophysics (“Astro2020”). If launched, Lynx would be the most powerful X-ray observatory constructed to date, enabling order-of-magnitude advances in capability over Chandra.

    NASA Parker Solar Probe Plus named to honor Pioneering Physicist Eugene Parker.

    NASA/Kepler Telescope, and K2 March 7, 2009 until November 15, 2018.

    NASA/Solar Dynamics Observatory.

    JAXA/NASA HINODE spacecraft.

    SAO is one of the 13 stakeholder institutes for the Event Horizon Telescope Board, and the CfA hosts its Array Operations Center. In 2019, the project revealed the first direct image of a black hole.

    Messier 87*, The first image of the event horizon of a black hole. This is the supermassive black hole at the center of the galaxy Messier 87. Image via JPL/ Event Horizon Telescope Collaboration released on 10 April 2019.

    The result is widely regarded as a triumph not only of observational radio astronomy, but of its intersection with theoretical astrophysics. Union of the observational and theoretical subfields of astrophysics has been a major focus of the CfA since its founding.

    In 2018, the CfA rebranded, changing its official name to the “Center for Astrophysics | Harvard & Smithsonian” in an effort to reflect its unique status as a joint collaboration between Harvard University and the Smithsonian Institution. Today, the CfA receives roughly 70% of its funding from NASA, 22% from Smithsonian federal funds, and 4% from the National Science Foundation. The remaining 4% comes from contributors including the United States Department of Energy, the Annenberg Foundation, as well as other gifts and endowments.

    The first results show that the intensity of the light produced by material around M87’s supermassive black hole was the lowest that had ever been observed. This produced ideal conditions for viewing the ‘shadow’ of the black hole, as well as being able to isolate the light from regions close to the event horizon from those tens of thousands of light-years away from the black hole.

    The combination of data from these telescopes, and current (and future) EHT observations, will allow scientists to conduct important lines of investigation into some of astrophysics’ most significant and challenging fields of study. For example, scientists plan to use these data to improve tests of Einstein’s Theory of General Relativity. Currently, uncertainties about the material rotating around the black hole and being blasted away in jets, in particular the properties that determine the emitted light, represent a major hurdle for these General Relativity tests.

    A related question that is addressed by today’s study concerns the origin of energetic particles called “cosmic rays,” which continually bombard the Earth from outer space. Their energies can be a million times higher than what can be produced in the most powerful accelerator on Earth, the Large Hadron Collider. The huge jets launched from black holes, like the ones shown in today’s images, are thought to be the most likely source of the highest energy cosmic rays, but there are many questions about the details, including the precise locations where the particles get accelerated. Because cosmic rays produce light via their collisions, the highest-energy gamma rays can pinpoint this location, and the new study indicates that these gamma-rays are likely not produced near the event horizon—at least not in 2017. A key to settling this debate will be comparison to the observations from 2018, and the new data being collected this week.

    “Understanding the particle acceleration is really central to our understanding of both the EHT image as well as the jets, in all their ‘colors’,” says co-author Sera Markoff from the University of Amsterdam. “These jets manage to transport energy released by the black hole out to scales larger than the host galaxy, like a huge power cord. Our results will help us calculate the amount of power carried, and the effect the black hole’s jets have on its environment.”

    The release of this new treasure trove of data coincides with the EHT’s 2021 observing run, which leverages a worldwide array of radio dishes, the first since 2018. Last year’s campaign was canceled because of the COVID-19 pandemic, and the previous year was suspended because of unforeseen technical problems. This very week, for six nights, EHT astronomers are targeting several supermassive black holes: the one in M87 again, the one in our Galaxy called Sagittarius A*, and several more distant black holes. Compared to 2017, the array has been improved by adding three more radio telescopes: the Greenland Telescope, the Kitt Peak 12-meter Telescope in Arizona, and the NOrthern Extended Millimeter Array (NOEMA) in France.

    “With the release of these data, combined with the resumption of observing and an improved EHT, we know many exciting new results are on the horizon,” says co-author Mislav Baloković of Yale University.

    “I’m really excited to see these results come out, along with my fellow colleagues working on the SMA, some of whom were directly involved in collecting some of the data for this spectacular view into M87,” says co-author Garrett Keating, a Submillimeter Array project scientist. “And with the results of Sagittarius A* — the massive black hole at the center of the Milky Way — coming out soon, and the resumption of observing this year, we are looking forward to even more amazing results with the EHT for years to come.”

  • richardmitnick 12:59 pm on October 26, 2020 Permalink | Reply
    Tags: "New analysis shows a “wobble” in the ring around a black hole", Avery Broderick talks about the latest Event Horizon Telescope work!, Black hole Messier 87*,   

    From University of Waterloo (CA): “New analysis shows a “wobble” in the ring around a black hole” Avery Broderick interviewed. 

    U Waterloo bloc

    From University of Waterloo (CA)

    October 26, 2020

    Avery Broderick talks about the latest Event Horizon Telescope work!

    When the first picture of a black hole, a gravitational well from which no light can escape, was unveiled last year, it was a stunning technological feat.

    That now-famous image of the black hole known as Messier 87* which is 55 million light years away in the Messier 87 galaxy, was the result of over a decade of work by hundreds of scientists and engineers who are part of the Event Horizon Telescope (EHT) collaboration that created an “earth-sized” telescope out of eight telescope facilities around the world.

    EHT map.

    Yet the culmination of all that work was just the beginning.

    Since then, the collaboration has been moving from black hole portraiture to black hole cinema.

    In the most recent work, scientists used the older, archival data sets from observations of M87* that date all the way back to 2009, when there were only three telescope sites in the collaboration.

    From that older data, combined with what they learned from the more recent observations, scientists constructed a moving image showing the “wobble” in the orientation of the bright crescent ring of plasma around M87* They are seeing the changes over time as the plasma is pushed and pulled by magnetic and gravitational forces in an extremely turbulent environment.

    The work was published in The Astrophysical Journal Monitoring the Morphology of M87* in 2009–2017 with the Event Horizon Telescope in September.

    We recently interviewed Avery Broderick, a professor at the University of Waterloo and an associate faculty member at Perimeter Institute for Theoretical Physics who has been a member of the EHT collaboration from the very beginning, about the latest work and what is in store for the future:

    Q: The historic black hole image of M87* that was unveiled last year came from observations made over a period of a few days in 2017. But this most recent work used much older data, from observations going back to 2009. Can you tell us about that?

    Broderick: By 2017, the Event Horizon Telescope had enough telescope stations around the earth to make the first complete images.

    But that was not the first time we’d run the experiment. In fact, we had a lot of confidence that it would work because we had been running these experiments for a decade prior.

    The first version of what would eventually become the Event Horizon telescope observed the black hole at center of our own galaxy in 2007. There were not enough stations back then to make an image, but from those observations we knew there was an image that could be made.

    In 2009, we began doing the same for M87*, and we executed observations periodically in the years after that. None of those observations on their own provided enough information to yield an image, but if you know what you’re looking for, you don’t need all the information.

    I use the example of a picture of my daughter, Anna, who had a nice yellow ensemble when she was younger. Sometimes we would tease her and call her Anna Banana. So, you can ask, how many pixels would you need to be able to know whether you are looking at a picture of Anna or a picture of a banana? Even if she’s wearing her yellow outfit, the answer is not that many. You can figure it out pretty fast.

    The same is true of astronomical objects. We now know that M87* is well-described by this ring-like asymmetric-structure that is like a doughnut brightened on one side. If we know it looks like that, then we can use the past data to figure out how it was oriented, and how large it was, going back to previous years.

    That is what this new paper is about. It is figuring out how to take all that legacy data and apply that to what we now know to be the truth, to help us understand how this structure might evolve in time.

    Q: Is this like an animation then?

    Broderick: It’s more like going through family photographs in an album and seeing how my daughter has grown. What she looked like when she was three and then five, etc.

    So, we now have this beautiful high-resolution image of M87* from the observations in 2017, but by going back over the earlier data, we can see how it changed from year to year.

    We are watching how that hairstyle evolved from one decade to the next, as it were.

    Q: When they put all of this together, scientists see what is described as a “wobble.” But what is this wobble? What’s wobbling?

    Broderick: You could ask, if we are looking at a black hole, how is it that we see anything at all?

    Black holes are, after all, supposed to be black like the night sky. But they also turn out to be some of the brightest objects in the universe because so often black holes are not found in isolation. They’re found in the company of stuff that is falling on the black hole, and as it does, it heats up and shines.

    What we are really making pictures of is this bright plasma that surrounds the event horizon.

    This plasma is very turbulent and it changes over time. All of our best calculations indicate that it isn’t a static, constant flow. Rather, it is a turbulent flow that is rushing headlong and creating absolute cacophony of light around the black hole.

    What we are seeing here is these excursions in the plasma from side to side. That’s the wobble.

    We can ask, given the models that we have for how turbulent plasmas around black holes work, how will this plasma around M87* behave from year to year? Does that comport with the size of the variations that we see? And the answer is yes. We’re beginning to nail down some statement – not quite a movie but at least some statement — about how it changes.

    Q: Was this wobble a surprise? Was it what you expected?

    Broderick: The only surprise was how successful we were in being able to do this with the data that we had from the past. That really is a tour de force of both the analysis tools and the dedication of the people involved.

    We did expect to see this kind of motion, and in fact this is something we think is critical to how material falls down into the black hole. The turbulent nature is not just incidental, but is required to drive material in.

    We never worry too much about the Earth falling into the Sun, for example, because of angular momentum conservation. But were the Earth to strongly interact with other bodies that could provide torques on the Earth’s orbit, e.g., nearby planets or a proto-planetary disk present in the early life of the solar system, then we might worry about that.

    Around black holes, there are magnetic interactions, not just gravitational interactions, that are critical in driving material in and out. These develop into a chaotic, frothing accretion flow. So, this turbulence is a key feature that we expected. It’s nice to see it confirmed.

    Q: What can you learn from this? What knowledge does it add?

    Broderick: One conclusion from the study is that this turbulent picture continues to look like it’s the right picture.

    It’s important for people to recognize that we are really at the very beginning of an incredible period of observational black hole astronomy.

    When I was a graduate student, the idea of actually seeing these things was simply science fiction. The study of black holes was done on blackboards and we would come up with mathematical models and theories for how these objects behaved.

    But no matter how well-informed the hypothesis is, what really matters is what the experiments say; many beautiful ideas in science have turned out to be simply wrong.

    So here we are checking. I think this is the first resolved study that demonstrates that, in fact, this turbulent picture is the correct one. The observations from the EHT collaboration are laying the foundation under the house that theory built for black hole astrophysics. That makes this an extremely exciting time.

    Q: How long have you been involved in this collaboration?

    Broderick: Since before it even had a name. I’ve been doing this for two decades.

    They don’t let me touch the telescopes, or at least they’re advised not to. My role in the collaboration is building models that make predictions for what we’re going to see, and trying to assess what it means when we have seen something.

    Q: How is your team at Waterloo involved in the most recent work to show the wobble?

    Broderick: What we do is develop the pipelines that go all the way from the pre-imaging data to the conclusions about the fundamental science questions that have driven the project and keep us all up at night.

    Another way of saying it is that our job is to bring the actual detailed observables of the Event Horizon Telescope into direct contact with the science questions that drove its construction.

    Towards that end, we’ve developed a large amount of software, we’ve developed a large number of models that facilitate this comparison, and then we execute them.

    This wobble paper, was enabled by that process. Once we develop the software, we shared it with the collaboration. Members of the collaboration then got the idea to go and build out this set of analyses of this prior data given what we know now. We’re very pleased that they’re using the tools we’ve built here in Waterloo and we’re very proud that it has succeeded so widely,

    A key feature of this toolkit is careful error estimation. It is especially important to be able to assess how well we can make quantitative statements about the size and orientation of the bright ring in this context. This allows us to extract cutting edge science even when our data volume is very small and our data is incomplete. The software tools, the analysis tools we developed, are really enabling technologies for this kind of historical inspection where the data quality is poor.

    Q: What is next for the EHT collaboration?

    Broderick: The M87* results that we published a year ago this past April were very much just the first.

    There are many more things we would like to know about how M87* changes. We want to look at the polarization, which tells us something about the magnetic fields. If the ring that we see is the color of the hairstyle, the magnetic fields might be the shape of the hairstyle.

    That’s important for our understanding of how these black holes launch the relativistic jets that we see coming from M87*. We can see these jets that are flung out at nearly light speed from the black hole. How does that happen? That’s something that astrophysicists have been talking about for many decades now, and here, we’re finally able to start getting empirical answers.

    But also, M87* is just one of the targets for the EHT collaboration. We are working very hard at making images, if not movies, of the supermassive black hole at the center of our own galaxy, Sgr A*. (abbreviation for Sagittarius A-Star).

    Q: That must be exciting for you. You are seeing the fruits of a very long collaboration.

    Broderick: It’s an extraordinary feeling. That’s right. One of the things that is funny is that now I’m an old man of the collaboration. I look at all the young postdocs and students working on this and they might lament about the data or about some aspect of the process, but I can say, “Well, look here, back when I was young, let me tell you how it was for us. You have eight stations, we had three!”

    Q: For this Zoom meeting, there is a background image of the bridge of the Starship Enterprise behind you. You have spoken in the past about the show Star Trek inspired you to explore the universe. So the exploration continues!

    Broderick: Yes, one day we might go around in the starships like this. But for now, I explore with telescopes and computers.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    U Waterloo campus

    In just half a century, the University of Waterloo (CA) located at the heart of Canada’s technology hub, has become a leading comprehensive university with nearly 36,000 full- and part-time students in undergraduate and graduate programs.

    Consistently ranked Canada’s most innovative university, Waterloo is home to advanced research and teaching in science and engineering, mathematics and computer science, health, environment, arts and social sciences. From quantum computing and nanotechnology to clinical psychology and health sciences research, Waterloo brings ideas and brilliant minds together, inspiring innovations with real impact today and in the future.

    As home to the world’s largest post-secondary co-operative education program, Waterloo embraces its connections to the world and encourages enterprising partnerships in learning, research, and commercialization. With campuses and education centres on four continents, and academic partnerships spanning the globe, Waterloo is shaping the future of the planet.

  • richardmitnick 9:34 am on October 25, 2020 Permalink | Reply
    Tags: Andrea Ghez of University of California Los Angeles (USA), , , , Black hole Messier 87*, , , , Reinhard Genzel of the MPG Institut für extraterrestrische Physik(DE), Roger Penrose of the University of Oxford (UK),   

    From EarthSky: “How the world came to understand black holes” We cannot get enough of these stories. 


    From EarthSky

    October 25, 2020
    Sayali Avachat

    Roger Penrose, Reinhard Genzel and Andrea Ghez. They are joint winners of 2020’s Nobel Prize in physics for their work on black holes. Credit: Nobel Media.

    Earlier this month (October 6, 2020), the Nobel Prize in physics was announced for two groundbreaking discoveries in astrophysics, both centered on black holes. Half of 2020’s prize went to mathematician Roger Penrose of the University of Oxford (UK) “for the discovery that black hole formation is a robust prediction of the general theory of relativity.” The other half went jointly to Reinhard Genzel of the MPG Institut für extraterrestrische Physik(DE) in Germany and Andrea Ghez of University of California, Los Angeles, “for the discovery of a supermassive compact object at the center of our galaxy.”

    It was a great moment for black hole physics as well as for the astronomy and astrophysics field in general. And it’s a wonderful time to contemplate the fascinating history of black hole science.

    What are black holes?

    Black holes are exotic objects in space. The classic scenario for black hole formation centers on a massive star that runs out of the internal fuel it needs to shine. The star collapses under the pull of its own self-gravity, leaving behind a high-density, compact object with an immense gravitational pull. A black hole is a place in space containing an object so dense and so compact that it forms a region around itself from which light cannot escape. The boundary of this region is known as an event horizon. Once past a black hole’s event horizon, the gravitational pull of the hole is inexorable.

    If there is material in space near the black hole – and if this material draws too close – it’s pulled inside. But it doesn’t just drop all at once into the hole; instead, it forms a glowing disk surrounding the black hole called an accretion disk. Friction within the accretion disk can heat the disk to billions of degrees, causing it to emit radiation across the electromagnetic spectrum. Thus, although no light can escape a black hole, astronomers can observe black holes in space via their accretion disks.

    What’s more, in the process of conservation of angular momentum, black holes can cause outbursts which come out perpendicular to the accretion disk. These outbursts are called jets by astronomers, and they can propel material out into space at relativistic speeds, that is, speeds that are a significant fraction of the speed of light (186,000 miles or 300,000 km per second). Astronomers can study black hole jets, too, to learn more about black holes.

    Development of theories of black holes

    All of the above was theory, developed in the 20th century. Albert Einstein’s General Theory of Relativity, published in 1916, contained the seeds of the modern concept of black holes, although the first ever mention of a similar concept is found in 1783, when an English natural philosopher by the name of John Michell theorized the existence of massive objects from which light cannot escape.

    Einstein’s theory of relativity discusses the curvature of space-time as a result of gravity. This curvature causes an object to move along a curved path equivalent to a straight line in the absence of gravity. The theory allowed for the existence of matter packed in small and infinitely warped space. The theory was published as The Field Equations of Gravitation in 1915.

    While serving in the German Army during World War I, astronomer and director of the Astrophysical Observatory in Potsdam Karl Schwarzschild was the first to solve Einstein’s field equations. His solution successfully described how space-time is curved, not just around a planet or a star, but also around theoretical high-density masses, such as black holes. In the space around an object that’s dense enough, and massive enough, gravity is so strong that even light – the fastest-moving stuff in the universe at 186,000 miles (300,000 km) per second – cannot escape. Thus it was Schwarzschild who first conceived of the event horizon, or boundary region around a black hole. Today, physicists speak of the Schwarzschild radius, which is (basically) the radius of a black hole’s event horizon. Schwarzschild’s solution to Einstein’s field equations also elegantly explained the concept of a singularity – the central point of a black hole – a point in space where all the laws of physics break down.

    At first, this concept was considered a mathematical curiosity. Scientists, including Einstein, had no idea such objects could exist in nature.

    But 50 years later, in 1965, Roger Penrose, working with the great theoretical physicist and cosmologist Stephen Hawking, showed that the black holes can indeed exist in nature and that they can form through a stable and robust process. And in fact, for some stars, black holes are the ultimate fate, an unavoidable outcome of stellar collapse.

    The momentous work by Penrose and Hawking opened a new era in the study of black holes. Penrose’s work was also pivotal in showing how black holes emit energy through the Penrose process, in the form of jets and outbursts.

    In the meantime, it was physicist John Wheeler who, in 1967, popularized the term black hole. Wheeler summarized Einstein’s equations as:

    “Space-time tells matter how to move; matter tells space-time how to curve.”

    Observations of black holes

    Astronomers didn’t discover the first stellar-mass black hole – Cygnus X-1 – until after the middle of the 20th century.

    Left: Image of Cygnus X-1 as observed by the Chandra X-ray observatory. Right: By now iconic artist’s concept of black hole accreting matter from its companion star. Image via (left) NASA/ CXC/ SAO; (right) NASA/ CXC/ M.Weiss.

    A 1964 rocket flight revealed Cygnus X-1 as one of the strongest sources of X-rays that had yet been seen from Earth. By the 1970s, most astronomers believed Cygnus X-1 was indeed a black hole. It’s now thought to be a black hole with a mass some 14.8 times that of our sun and an event horizon with a radius of around 27 miles (44 km). That’s in contrast to our sun’s radius of about 433,000 miles (696,000 km).

    Stellar-mass black holes are hard to find because of their quiescent nature. They might display short and unpredictable outbursts when some passing material strikes their accretion disks, after which they might go quiet for decades.

    That is why it took the discovery of supermassive black holes at the centers of most galaxies, including our own Milky Way, to give black hole science its real boost.

    Supermassive black holes

    Today, astronomers believe that most galaxies harbor supermassive black holes in their centers. Supermassive black holes have masses equivalent to millions to billions of solar masses and are believed to form in the centers of galaxies around the same time as the galaxy is forming. Over 100,000 supermassive black hole candidates have been observed to date, many more than the number of known stellar-mass black holes.

    Among the many observed black hole candidates, the one at the center of our own Milky Way galaxy is called Sagittarius A* (Sgr A*, pronounced Sagittarius A-star). Two independent studies carried out in the last 25 years, led by Andrea Ghez and Reinhard Genzel – joint winners of half of 2020’s Nobel prize in physics – mapped the stars orbiting an invisible object at the center of our Milky Way. Using the powerful telescopes at Keck Observatory in Hawaii and the Very Large Telescope in Chile, the teams focused on one star known as S0-2. S0-2 orbits closer to our galaxy’s central supermassive black hole than any other observed star.

    Keck Observatory, operated by Caltech and the University of California, Maunakea Hawaii USA, altitude 4,207 m (13,802 ft).

    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.

    Knowing the orbital period of the star S0-2, its very elongated elliptical orbit and the distance of its closest approach to our galaxy’s central black hole enabled scientists to calculate the mass of Sgr A* as the equivalent of 4 million solar masses. The teams were able to observe two full orbits of the star S0-2 around the central black hole, which further bolstered their claims and also proved, through observations, what Einstein, Schwarzchild, and Penrose had predicted in theory about black holes.

    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.

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

    Further validation of Einstein’s general theory of relativity came when, on April 10, 2019, the Event Horizon Telescope collaboration released the first-ever image of [the event horizon] of a black hole* in the relatively nearby (by cosmic standards) galaxy known as Messier 87, visible in the constellation Virgo.

    The gargantuan black hole in Messier 87’s center, Messier 87*, weighs a whopping 6.5 billion solar masses.

    Messier 87*, The first image of the event horizon of a black hole. This is the supermassive black hole at the center of the galaxy Messier 87. Image via JPL/ Event Horizon Telescope Collaboration released on 10 April 2019.

    The galaxy Messier 87 and its famous jet – an energetic outflow of high energy particles from its center – had been observed for several decades. However, this was the first ever successful attempt at direct imaging of its [event horizon]. The image shows a bright ring formed by the bending of light at the boundary of the black hole’s event horizon, caused by its extreme gravitational pull.

    *One cannot speak of the image of the black hole itself, because no light emerges from the black hole. It is, after all, black. All that can be imaged is the event horizon which is the thin area which surrounds the black hole.

    See the full article here .

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.orgin 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.

  • richardmitnick 8:16 am on September 24, 2020 Permalink | Reply
    Tags: "The ring around the black hole glitters", , , , Black hole Messier 87*, , ,   

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

    From Max Planck Institute for Radio Astronomy

    September 23, 2020

    Dr. Norbert Junkes
    Press and public relations
    Max Planck Institute for Radio Astronomy, Bonn
    +49 2 28525-399

    Prof. Dr. J. Anton Zensus
    Max Planck Institute for Radio Astronomy, Bonn
    +49 228 525-378

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

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

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

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

    EHT map

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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


    Please help promote STEM in your local schools.

    Stem Education Coalition

    MPIFR/Effelsberg Radio Telescope, Germany

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

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

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

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

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

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

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

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

    The Max Planck Institutes focus on excellence in research. The Max Planck Society has a world-leading reputation as a science and technology research organization, with 33 Nobel Prizes awarded to their scientists, and is generally regarded as the foremost basic research organization in Europe and the world. In 2013, the Nature Publishing Index placed the Max Planck institutes fifth worldwide in terms of research published in Nature journals (after Harvard, MIT, Stanford and the US NIH). In terms of total research volume (unweighted by citations or impact), the Max Planck Society is only outranked by the Chinese Academy of Sciences, the Russian Academy of Sciences and Harvard University. The Thomson Reuters-Science Watch website placed the Max Planck Society as the second leading research organization worldwide following Harvard University, in terms of the impact of the produced research over science fields.

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