The European Southern Observatory is a 16-nation intergovernmental research organisation for astronomy. Created in 1962, ESO has provided astronomers with state-of-the-art research facilities and access to the southern sky. The organisation employs about 730 staff members and receives annual member state contributions of approximately €131 million. Its observatories are located in northern Chile.ESO has built and operated some of the largest and most technologically-advanced telescopes. These include the New Technology Telescope, an early pioneer in the use of active optics, and the Very Large Telescope , which consists of four individual telescopes, each with a primary mirror 8.2 metre across, and four smaller auxiliary telescopes. The Atacama Large Millimeter Array observes the universe in the millimetre and submillimetre wavelength ranges, and is the world's largest ground-based astronomy project to date. It was completed in March 2013 in an international collaboration by Europe , North America, East Asia and Chile.Currently under construction is the European Extremely Large Telescope. It will use a 39.3-metre-diameter segmented mirror, and become the world's largest optical reflecting telescope when operational in 2024. Its light-gathering power will allow detailed studies of planets around other stars, the first objects in the universe, supermassive black holes, and the nature and distribution of the dark matter and dark energy which dominate the universe.ESO's observing facilities have made astronomical discoveries and produced several astronomical catalogues. Its findings include the discovery of the most distant gamma-ray burst and evidence for a black hole at the centre of the Milky Way. In 2004, the VLT allowed astronomers to obtain the first picture of an extrasolar planet orbiting a brown dwarf 173 light-years away. The High Accuracy Radial Velocity Planet Searcher instrument installed in another ESO telescope led to the discovery of extrasolar planets, including Gliese 581c—one of the smallest planets seen outside the solar system. Wikipedia.
News Article | April 17, 2017
The birthplace of black holes is to be found in the peaceful village of Thornhill in the English county of Yorkshire. In the 18th century, this is where John Michell made his home, next to the medieval church. He was the rector here for 26 years and – as borne out by the inscription on his memorial in the church – highly respected as a scholar as well. In fact, Michell had studied not only theology, Hebrew and Greek at Cambridge, but had also turned his attention to the natural sciences. His main interest was geology. In one treatise, which was published after the Lisbon earthquake of 1755, he claimed that subterranean waves existed which propagated such an earthquake. This theory caused quite a stir in the academic world, and led to John Michell being accepted as a Fellow of the Royal Society in London, not least because of this theory. He gave a talk before this renowned society in 1783 on the gravitation of stars. He used a thought experiment to explain that light would not leave the surface of a very massive star if the gravitation was sufficiently large. And he deduced: "Should such an object really exist in nature, its light could never reach us." More than a decade after Michell, another scientist took up this same topic: in his book published in 1796 - Exposition du Système du Monde - the French mathematician, physicist and astronomer Pierre-Simon de Laplace described the idea of massive stars from which no light could escape; this light consisted of corpuscles, very small particles, according to the generally accepted theory of Isaac Newton. Laplace called such an object corps obscur, i.e. dark body. The physical thought games played by John Michell and Pierre-Simon de Laplace did not meet with much response, however, and were quickly forgotten. It was left to Albert Einstein with his General Theory of Relativity to pave the way for these "dark bodies" to enter the realms of science – without this really being his intention. Although the existence of point singularities, in which matter and radiation from our world would simply disappear, can be derived from the equations he published in 1915, 1939 saw Einstein publish an article in the journal Annals of Mathematics in which he intended to prove that such black holes were impossible. But back in 1916, the astronomer Karl Schwarzschild had taken the Theory of General Relativity as his basis to calculate the size and the behaviour of a non-rotating static black hole carrying no electric charge. His name has been given to the mass-dependent radius of such an object, inside which nothing can escape to the outside. This radius would be around one centimetre for Earth. Schwarzschild had a meteoric career during his short life. Born in 1873 as the eldest of six children of a German-Jewish family in Frankfurt, his talent emerged at an early age. He was only 16 when he published two papers in a renowned journal on the determination of the orbits of planets and binary stars. His subsequent career in astronomy took him via Munich, Vienna and Göttingen to Potsdam, where he became director of the astrophysical observatory in 1909. A few years later, in the middle of Word War I – Karl Schwarzschild was artillery second lieutenant on the Eastern front in Russia – he derived the exact solutions for Einstein's field equations. He died on 11 May 1916 from an auto-immune disease of the skin. The topic of black holes did not yet find its way into the scientific domain, however. If anything, the interest in Einstein's theoretical construct diminished more and more after the initial hype. This phase lasted approximately from the mid-1920s to the middle of the 1950s. Then followed what the physicist Clifford Will called the "renaissance" of the General Theory of Relativity. It now became important to describe objects which initially were only of interest to the theoreticians. White dwarves, for example, or neutron stars where matter exists in very extreme states. Their unexpected properties could be explained with the aid of new concepts derived from this theory. So the black holes moved into the focus of attention as well. And scientists working on them became stars – like the British physicist Stephen Hawking. At the beginning of the 1970s, Uhuru heralded in a new era for observational astronomy. The satellite surveyed the universe in the range of extremely short wavelength X-ray radiation. Uhuru discovered hundreds of sources, usually neutron stars. But among them was one particular object in the Cygnus (=swan) constellation. It was given the designation Cygnus X-1. Researchers discovered it to be a giant star of around 30 solar masses which shone with a blue glow. An invisible object of around 15 solar masses orbits around it – apparently a black hole. This also explains the X-rays recorded: the gravity of the black hole attracts the matter of the main star. This collects in a so-called accretion disk around the massive monster, swirls around it at incredibly high speed, is heated up to several million degrees by the friction – and emits X-rays before it disappears in the space-time chasm. Cygnus X-1 is by no means the only black hole which the astronomers have detected indirectly. So far, they have found a whole series of them with between 4 and 16 solar masses. But there is one which is much more massive. It is located at the heart of our Milky Way, around 26,000 light years away, and was discovered at the end of the 1990s. In 2002, a group including Reinhard Genzel from the Max Planck Institute for Extraterrestrial Physics succeeded in making a sensational discovery: at the Very Large Telescope of the European Southern Observatory (ESO), the scientists observed a star which had approached the galactic centre to within a mere 17 light hours (just over 18 billion kilometres). During the months and years that followed, they were able to observe the orbital motion of this star, which was given the designation S2. It orbits the centre of the galaxy (Sagittarius A*) once every 15.2 years at a speed of 5000 kilometres per second. From the motion of S2 and other stars, the astronomers concluded that around 4.5 million solar masses are concentrated in a region the size of our planetary system. There is only one plausible explanation for such a density: a gigantic black hole. Our Milky Way is no exception: the scientists believe that these mass monsters lurk at the centres of most galaxies – some even much larger than Sagittarius A*. A black hole of approx. 6.6 billion solar masses is located inside a giant galaxy known as M87! Like Sagittarius A*, this stellar system 53 million light years away is also part of the observation programme of the Event Horizon Telescope. With the discovery of gravitational waves in September 2015, the history of black holes reached its present climax. At that time, waves from two merging holes with 36 and 29 solar masses were registered. This heralded in a new era of astronomy, whose aim is to bring light into the dark universe. And also to shed light on these mysterious black holes. Explore further: Astronomers hoping to directly capture image of a black hole
News Article | April 28, 2017
An international team of astrophysicists led by a scientist from the Sternberg Astronomical Institute of the Lomonosov Moscow State University reported the discovery of a binary solar-type star inside the supernova remnant RCW 86. Spectroscopic observation of this star revealed that its atmosphere is polluted by heavy elements ejected during the supernova explosion that produced RCW 86. In particular, it was found that the calcium abundance in the stellar atmosphere exceeds the solar one by a factor of six, which hints at the possibility that the supernova might belong to the rare type of calcium-rich supernovae - the enigmatic objects, whose origin is yet not clear. The research results are published in Nature Astronomy on 2017 April, 24. The evolution of a massive star ends with a violent explosion called a supernova. The central part of the exploded star contracts into a neutron star, while the outer layers expand with a huge velocity and form an extended gaseous shell called supernova remnant (SNR). Currently, several hundreds of SNRs are known in the Milky Way, of which several tens were found to be associated with neutron stars. Detection of new examples of neutron stars in SNRs is very important for understanding the physics of supernova explosions. In 2002 Vasilii Gvaramadze, a scientist from the Sternberg Astronomical Institute, proposed that the pyriform appearance of RCW 86 can be due to a supernova explosion near the edge of a bubble blown by the wind of a moving massive star - the supernova progenitor star. This allowed him to detect a candidate neutron star, currently known as [GV2003] N, associated with RCW 86 using the data from the Chandra X-ray Observatory. If [GV2003] N is indeed a neutron star, then it should be a very weak source of optical emission. But in the optical image obtained in 2010, a quite bright star was detected at the position of [GV2003] N. This could mean that [GV2003] N was not a neutron star. Vasilii Gvaramadze, the leading author of the Nature Astronomy publication, explains: "In order to determine the nature of the optical star at the position of [GV2003] N, we obtained its images using seven-channel optical/near-infrared imager GROND at the 2.2-metre telescope of the European Southern Observatory (ESO). Spectral energy distribution has shown that this star is of solar type (so-called G star). But since the X-ray luminosity of the G star should be significantly less than that was measured for [GV2003] N, we have come to a conclusion that we deal with a binary system, composed of a neutron star (visible in X-rays as [GV2003] N) and a G star (visible in optical wavelengths)". The existence of such systems is a natural result of massive binary star evolution. Recently, it was recognized that the majority of massive stars form in binary and multiple systems. When one of the stars explodes in a binary system, the second one could become polluted by heavy elements, ejected by a supernova. To check the hypothesis that [GV2003] N is a binary system, astrophysicists have got four spectra of the G star in 2015 with the Very Large Telescope (VLT) of the ESO. It was found that the radial velocity of this star has significantly changed during one month, which is indicative of an eccentric binary with an orbital period of about a month. The obtained result has proved that [GV2003] N is a neutron stars and that RCW 86 is the result of supernova explosion near the edge of a wind-blown bubble. This is very important for understanding the structure of some peculiar SNRs as well as for detection of their associated neutron stars. Until recently, the most popular explanation of the origin of the calcium-rich supernovae was the helium shell detonation on low-mass white dwarfs. The results obtained by Vasilii Gvaramadze and his colleagues, however, imply that under certain circumstances a large amount of calcium could also be synthesized by explosion of massive stars in binary systems. Vasilii Gvaramadze sums up: "We continue studying [GV2003] N. We are going to determine orbital parameters of the binary system, estimate the initial and final masses of the supernova progenitor, and the kick velocity obtained by the neutron star at birth. Moreover, we are also going to measure abundances of additional elements in the G star atmosphere. The obtained information could be crucially important for understanding the nature of the calcium-rich supernovae".
Agency: European Commission | Branch: H2020 | Program: RIA | Phase: INFRAIA-01-2016-2017 | Award Amount: 10.51M | Year: 2017
RadioNet is a consortium of 28 institutions in Europe, Republic of Korea and South Africa, integrating at European level world-class infrastructures for research in radio astronomy. These include radio telescopes, telescope arrays, data archives and the globally operating European Network for Very Long Baseline Interferometry (EVN). RadioNet is de facto widely regarded to represent the interests of radio astronomy in Europe. A comprehensive, innovative and ambitious suite of actions is proposed that fosters a sustainable research environment. Building on national investments and commitments to operate these facilities, this specific EC program leverages the capabilities on a European scale. The proposed actions include: - Merit-based trans-national access to the RadioNet facilities for European and for the first time also for third country users; and integrated and professional user support that fosters continued widening of the community of users. - Innovative R&D, substantially enhancing the RadioNet facilities and taking leaps forward towards harmonization, efficiency and quality of exploitation at lower overall cost; development and delivery of prototypes of specialized hardware, ready for production in SME industries. - Comprehensive networking measures for training, scientific exchange, industry cooperation, dissemination of scientific and technical results; and policy development to ensure long-term sustainability of excellence for European radio astronomy. RadioNet is relevant now, it enables cutting-edge science, top-level R&D and excellent training for its European facilities; with the Atacama Large Millimetre Array (ALMA) and the ESFRI-listed Square Kilometre Array (SKA) defined as global radio telescopes, RadioNet assures that European radio astronomy maintains its leading role into the era of these next-generation facilities by involving scientists and engineers in the scientific use and innovation of the outstanding European facilities.
Agency: European Commission | Branch: FP7 | Program: CP-CSA-Infra | Phase: INFRA-2012-1.1.25. | Award Amount: 10.98M | Year: 2013
Optical-infrared astronomy in Europe is in a state of transition and opportunity, with the goal of a viable structured European scale community in sight. A strong astronomical community requires access to state of the art infrastructures (telescopes), equipped with the best possible instrumentation, and with that access being open to all on a basis of competitive excellence. Further, the community needs training in optimal use of those facilities to be available to all, Critically, it needs a viable operational model, with long-term support from the national agencies, to operate those infrastructures. The most important need for most astronomers is to have open access to a viable set of medium aperture telescopes, with excellent facilities, complemented by superb instrumentation on the extant large telescopes, while working towards next generation instrumentation on the future flagship, the European Extremely Large Telescope. OPTICON has made a substantial contribution to preparing the realisation of that ambition. OPTICON supported R&D has, and is developing critical next-generation technology, to enhance future instrumentation on all telescopes. The big immediate challenge is to retain a viable set of well-equipped medium aperture telescopes. The present project is to make the proof of principle that such a situation is possible - a situation developed by OPTICON under its previous contracts, in collaboration with the EC supported strategy network ASTRONET - and set the stage for the step to full implementation.
Agency: European Commission | Branch: H2020 | Program: RIA | Phase: INFRAIA-01-2016-2017 | Award Amount: 10.01M | Year: 2017
Europe has become a global leader in optical-near infrared astronomy through excellence in space and ground-based experimental and theoretical research. While the major infrastructures are delivered through major national and multi-national agencies (ESO, ESA) their continuing scientific competitiveness requires a strong community of scientists and technologists distributed across Europes nations. OPTICON has a proven record supporting European astrophysical excellence through development of new technologies, through training of new people, through delivering open access to the best infrastructures, and through strategic planning for future requirements in technology, innovative research methodologies, and trans-national coordination. Europes scientific excellence depends on continuing effort developing and supporting the distributed expertise across Europe - this is essential to develop and implement new technologies and ensure instrumentation and infrastructures remain cutting edge. Excellence depends on continuing effort to strengthen and broaden the community, through networking initiatives to include and then consolidate European communities with more limited science expertise. Excellence builds on training actions to qualify scientists from European communities which lack national access to state of the art research infrastructures to compete successfully for use of the best available facilities. Excellence depends on access programmes which enable all European scientists to access the best infrastructures needs-blind, purely on competitive merit. Global competitiveness and the future of the community require early planning of long-term sustainability, awareness of potentially disruptive technologies, and new approaches to the use of national-scale infrastructures under remote or robotic control. OPTICON will continue to promote this excellence, global competitiveness and long-term strategic planning.
Agency: European Commission | Branch: FP7 | Program: ERC-SyG | Phase: ERC-2013-SyG | Award Amount: 13.98M | Year: 2014
Gravity is successfully described by Einsteins theory of general relativity (GR), governing the structure of our entire universe. Yet it remains the least understood of all forces in nature, resisting unification with quantum physics. One of the most fundamental predictions of GR are black holes (BHs). Their defining feature is the event horizon, the surface that light cannot escape and where time and space exchange their nature. However, while there are many convincing BH candidates in the universe, there is no experimental proof for the existence of an event horizon yet. So, does GR really hold in its most extreme limit? Do BHs exist or are alternatives needed? Here we propose to build a Black Hole Camera that for the first time will take an actual picture of a BH and image the shadow of its event horizon. We will do this by providing the equipment and software needed to turn a network of existing mm-wave radio telescopes into a global interferometer. This virtual telescope, when supplemented with the new Atacama Large Millimetre Array (ALMA), has the power to finally resolve the supermassive BH in the centre of our Milky Way the best-measured BH candidate we know of. In order to compare the image with the theoretical predictions we will need to perform numerical modelling and ray tracing in GR and alternative theories. In addition, we will need to determine accurately the two basic parameters of the BH: its mass and spin. This will become possible by precisely measuring orbits of stars with optical interferometry on ESOs VLTI. Moreover, our equipment at ALMA will allow for the first detection of pulsars around the BH. Already a single pulsar will independently determine the BHs mass to one part in a million and its spin to a few per cent. This unique combination will not only produce the first-ever image of a BH, but also turn our Galactic Centre into a fundamental-physics laboratory to measure the fabric of space and time with unprecedented precision.
Agency: European Commission | Branch: FP7 | Program: CP-CSA-Infra | Phase: INFRA-2011-1.1.21. | Award Amount: 11.58M | Year: 2012
RadioNet is an I3 that coordinates all of Europes leading radio astronomy facilities in an integrated cooperation to achieve transformational improvement in the quality and quantity of the scientific research of European astronomers. RadioNet3 includes 27 partners operating world-class radio telescopes and/or performing cutting-edge R&D in a wide range of technology fields important for radio astronomy. RadioNet3 proposes a work plan that is structured into 6 NAs, 7 TNAs and 4 JRAs with the aim to integrate and optimise the use and development of European radio astronomy infrastructures. The general goals of RadioNet3 are to: - facilitate, for a growing community of European researchers, access to the complete range of Europes world-leading radio-astronomical facilities, including the ALMA telescope; - secure a long-term perspective on scientific and technical developments in radio astronomy, pooling resources and expertise that exist among the partners; - stimulate new R&D activities for the existing radio infrastructures in synergy with ALMA and the SKA; - contribute to the implementation of the vision of the ASTRONET Strategic Plan for European Astronomy by building a sustainable and world leading radio astronomical research community. RadioNet3 builds on the success of two preceeding I3s under FP6 and FP7, but it also takes a leap forward as it includes facilitation of research with ALMA via a dedicated NA, and 4 pathfinders for the SKA in its TNA Program. It has a transparent and efficient management structure designed to optimally support the implementation of the project. RadioNet is now recognized by funding agencies and international project consortia as the European entity representing radio astronomy and facilitating the access to and exploitation of excellent facilities in this field. This is of paramount importance, as a dedicated, formal European radio astronomy organisation to coordinate and serve the needs of this community does not yet exist.
Kennicutt Jr. R.C.,University of Cambridge |
Evans N.J.,University of Texas at Austin |
Evans N.J.,European Southern Observatory
Annual Review of Astronomy and Astrophysics | Year: 2012
We review progress over the past decade in observations of large-scale star formation, with a focus on the interface between extragalactic and Galactic studies. Methods of measuring gas contents and star-formation rates are discussed, and updated prescriptions for calculating star-formation rates are provided. We review relations between star formation and gas on scales ranging from entire galaxies to individual molecular clouds. Copyright © 2012 by Annual Reviews.