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  • richardmitnick 8:32 pm on May 19, 2015 Permalink | Reply
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    From ALMA: “ALMA Reveals the Cradles of Dense Cores: the Birthplace of Massive Stars” 

    ESO ALMA Array
    ALMA

    19 May 2015
    Valeria Foncea
    Education and Public Outreach Officer
    Joint ALMA Observatory
    Santiago, Chile
    Tel: +56 2 467 6258
    Cell: +56 9 75871963
    Email: vfoncea@alma.cl

    Masaaki Hiramatsu
    Education and Public Outreach Officer, NAOJ Chile
    Observatory Tokyo, Japan
    Tel: +81 422 34 3630
    E-mail: hiramatsu.masaaki@nao.ac.jp

    Charles E. Blue
    Public Information Officer
    National Radio Astronomy Observatory
    Charlottesville, Virginia, USA
    Tel: +1 434 296 0314
    Cell: +1 434.242.9559
    E-mail: cblue@nrao.edu

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

    A Taiwanese research team used the Atacama Large Millimeter/submillimeter Array (ALMA) to observe a large molecular gas clump [1] named G33.92+0.11, where a cluster with massive stars is forming. The excellent imaging power of ALMA allowed to reveal with unprecedented detail, the fine structure of the molecular gas at the center of the region, where two surprisingly large molecular gas arms, with sizes of ~ 3.2 light years [2], appear to be spiraling around two massive molecular cores. These results showed that the large molecular arms are indeed the cradles of dense cores, which are current or future birthplaces of massive stars. This is a crucial step forward in the understanding of how mass distributes to form both massive cores and massive stars.

    How the gravitationally bound stellar clusters, for example, the young massive clusters (YMCs) and globular clusters (GCs) come to the existence, remains a fundamental problem in astrophysics. To form such complex systems, it is required that massive amounts of gas can be converted with little losses, into stars, before they start to disperse the gas by the action of their winds —the so called stellar feedback—, and such process is far from trivial. Current models propose that in order to quench the action of stellar feedback, the global collapse of the parent molecular cloud has to be very rapid.

    However, this global collapse of giant [3] molecular clouds (GMC) represents an observational challenge for astronomers, because they cannot measure distances along their line of sight (data is projected in two dimensions) and because it is near impossible to measure gas velocities in the transverse directions. Nevertheless, the amplified effects of the initial rotation (angular momentum) of the clouds may translate into the formation of massive molecular clumps that are supported by centrifugal forces at the center of the collapsing GMC.

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    Figure 1: An overview of a massive stellar cluster-forming molecular cloud from numerical hydrodynamical simulations (courtesy from James Dale [5]), and the context of the scale of the ALMA observations for the deeply embedded central few light-years region. Credit: ALMA(ESO/NAOJ/NRAO), H. B. Liu, J. Dale.

    The identification of rotating structures at scales larger than the cores, may serve as evidence of such an outcome of global collapse. Also, because the massive molecular clumps are the densest regions in a collapsing GMC, they are likely the sites where the most massive stars of stellar clusters can form. To resolve the details of the morphology and kinematics of these systems will be key to understand how mass distributes in the sites of star cluster formation, such that it can form both massive and not massive stars.

    A research team led by Hauyu Baobab Liu at the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA) observed with ALMA the luminous OB cluster-forming region G33.92+0.11, located at a distance of about 23.000 lightyears. This source is at a beginning phase of forming an OB association, which has a contained luminosity of 250 thousand times the luminosity of the Sun. Most of this light is provided by a few embedded massive stars. The research team used the archival Herschel 350 μm, which were combined with another 350 μm image from the Caltech Submillimeter Observatory(CSO) with a higher angular resolution.

    Caltech Submillimeter Observatory
    CSO

    “The Herschel Space Telescope archive images provided a high quality map of the 350 μm thermal emission of the external dusty gas structures around G33.92+0.11.

    ESA Herschel
    ESA/Herschel

    We completed the missing small-scale pixels of this map with data from the Caltech Submillimeter Observatory. The final map revealed two molecular arms twisted in opposite directions, north and south of the cluster, converging at the central molecular clumps, indicating that perhaps the gas is being transported toward the central cluster along these spiral arms from distances as large as 20 light years,” says co-author Román-Zúñiga, from the Astronomy Institute of the Universidad Nacional Autónoma de México.

    2
    Figure 2: The central part of the OB cluster-forming region G33.92+0.11, observed by ALMA. Left: Dust continuum image taken at 1.3 mm. Right: False color image showing the integrated emission of three molecules: CH3CN in yellow, 13CS in green, and DCN in magenta, respectively. The CH3CN emission mainly traces the hot molecular cores, which harbor massive stars. The 13CS emission traces warm dense gas and shocks. The DCN emission appears to follow the bulk of dense gas traced by the dust continuum emission. Credit: ALMA(ESO/NAOJ/NRAO), H. B. Liu et al.

    The unprecedented high angular resolution and high imaging fidelity of ALMA allowed the astronomers to reveal in G33.92+0.11 A two centrally located massive molecular cores (~100-300 solar masses), connected by several spiraling dense molecular gas arms. This kind of morphology resembles the previous ALMA images of molecular gas arms surrounding the low-mass protostellar binary L1551 NE [4], however, but linearly scaled-up by a factor between 100 and 1000 (Figure 1). In addition, the observed gas arms in G33.92+0.11 A appear to be fragmenting, which results in the formation of multiple satellite cores orbiting the central two highest mass cores. Comparing the simultaneously observed molecular gas tracers including CH3CN, 13CS, and DCN shows that the gas excitation conditions in these molecular arms and cores far from being uniform across the system (Figure 2). For instance, the two highest mass cores at the center already harbor massive stars and present bright CH3CN emission. The molecular arms embedded with satellite cores in the north may be relatively cool, indicated by the good correlation between the DCN line and the 1.3 mm dust continuum emission. Finally the molecular arms connecting the central massive molecular cores from the west may contain gas that is shocked to a higher temperature or are subject to stellar heating and show stronger 13CS emission.

    This team propose that the central ~1 pc scale region of G33.92+0.11 A is a flattened, massive molecular clump that is currently accreting material, which is being fed by the exterior gas filaments, and is marginally supported by centrifugal forces. At all spatial scales, the regions of higher density, that contain larger amounts of mass, form at the center of the system. Accretion may be prohibited by the angular momentum, but might be alleviated by fragmentation. The authors further propose that in the dense eccentric accretion flows, the formation of spiraling arm-like structures may be essential to the process. The subsequent fragmentation of the dense molecular arms may lead to the formation of the second generation high-mass stars.

    “Gas structures similar to spiral arms should be common in many systems at many different scales, as long as they are unstable to gravity and have non-negligible rotation. The superb images made with ALMA are starting to show this,” says co-author Galván-Madrid.

    Notes

    [1] In our nomenclature, massive molecular clumps refer to dense molecular gas structures with sizes of ∼0.5-1 pc, massive molecular cores refer to the <0.1 pc size overdensities embedded within a clump, and condensations refer to the distinct molecular substructures within a core. Fragmentation refers to the dynamical process that produces or enhances the formation of multiple objects.

    [2] 1 parsec (pc) ~ 3.2 light years ~ 3.086×1016 meters.

    [3] The typical spatial scales of stellar cluster-forming molecular clouds are 101-2 pc.

    [4] More in the press release Dec 04, 2014: Astronomers Identify Gas Spirals as a Nursery of Twin Stars through ALMA Observation

    [5] For details, please see Dale, J. E., Ngoumou, J., Ercolano, B., Bonnell, I. A., 2014, MNRAS, 442, 694

    More information

    These observational results were published in the Astrophysical Journal (ApJ, 804, 37) by Liu et al. as ALMA resolves the spiraling accretion flow in the luminous OB cluster forming region G33.92+0.11.

    This research was conducted by Hauyu Baobab Liu (Academia Sinica Institute of Astronomy and Astrophysics); Roberto Galván-Madrid (Centro de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México); Izaskun Jiménez-Serra (Department of Physics and Astronomy, University College London and European Southern Observatory, Garching Germany); Carlos Román-Zúñiga (Instituto de Astronomía, Universidad Nacional Autónoma de México); Qizhou Zhang (Harvard-Smithsonian Center for Astrophysics); Zhiyun Li (Department of Astronomy, University of Virginia); Huei-Ru Chen (Institute of Astronomy and Department of Physics, National Tsing Hua University).

    See the full article here.

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

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

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  • richardmitnick 3:02 pm on May 7, 2015 Permalink | Reply
    Tags: ALMA, , , ,   

    From ALMA: “ALMA Discovers Proto Super Star Cluster — a Cosmic ‘Dinosaur Egg’ About to Hatch” 

    ESO ALMA Array
    ALMA

    07 May 2015
    Valeria Foncea
    Education and Public Outreach Officer
    Joint ALMA Observatory
    Santiago, Chile
    Tel: +56 2 467 6258
    Cell: +56 9 75871963
    Email: vfoncea@alma.cl

    Charles E. Blue
    Public Information Officer
    National Radio Astronomy Observatory
    Charlottesville, Virginia, USA
    Tel: +1 434 296 0314
    Cell: +1 434.242.9559
    E-mail: cblue@nrao.edu

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

    Masaaki Hiramatsu
    Education and Public Outreach Officer, NAOJ Chile
    Observatory Tokyo, Japan
    Tel: +81 422 34 3630
    E-mail: hiramatsu.masaaki@nao.ac.jp

    1
    The Antennae galaxies, shown in visible light in a Hubble image (upper image), were studied with ALMA, revealing extensive clouds of molecular gas (center right image). One cloud (bottom image) is incredibly dense and massive, yet apparently star free, suggesting it is the first example of a prenatal globular cluster ever identified. Credit: NASA/ESA Hubble, B. Whitmore (STScI); K. Johnson, U.Va.; ALMA (NRAO/ESO/NAOJ); B. Saxton (NRAO/AUI/NSF).

    NASA Hubble Telescope
    NASA/ESA Hubble

    NRAO VLA
    NRAO/VLA

    Globular clusters – dazzling agglomerations of up to a million ancient stars – are among the oldest objects in the universe. Though plentiful in and around many galaxies, newborn examples are vanishingly rare and the conditions necessary to create new ones have never been detected, until now.

    Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have discovered what may be the first known example of a globular cluster about to be born: an incredibly massive, extremely dense, yet star-free cloud of molecular gas.

    “We may be witnessing one of the most ancient and extreme modes of star formation in the universe,” said Kelsey Johnson, an astronomer at the University of Virginia in Charlottesville and lead author on a paper accepted for publication in the Astrophysical Journal. “This remarkable object looks like it was plucked straight out of the very early universe. To discover something that has all the characteristics of a globular cluster, yet has not begun making stars, is like finding a dinosaur egg that’s about to hatch.”

    This object, which the astronomers playfully refer to as the “Firecracker,” is located approximately 50 million light-years away from Earth nestled inside a famous pair of interacting galaxies (NGC 4038 and NGC 4039), which are collectively known as the Antennae galaxies. The tidal forces generated by their ongoing merger are triggering star formation on a colossal scale, much of it occurring inside dense clusters.

    2
    NGC 4038 (left) and NGC 4039 (right)

    What makes the Firecracker unique, however, is its extraordinary mass, comparatively small size, and apparent lack of stars.

    All other globular cluster analogues astronomers have observed to date are already brimming with stars. The heat and radiation from these stars have therefore altered the surrounding environment considerably, erasing any evidence of its colder, quieter beginnings.

    2
    ALMA image of dense cores of molecular gas in the Antennae galaxies. The round yellow object near the center may be the first prenatal example of a globular cluster ever identified. It is surrounded by a giant molecular cloud. Credit: K. Johnson, U.Va.; ALMA (NRAO/ESO/NAOJ).

    With ALMA, the astronomers were able to find and study in detail a pristine example of such an object before stars forever change its unique characteristics. This afforded astronomers a first-ever glimpse of the conditions that may have led to the formation of many, if not all globular clusters.

    “Until now, clouds with this potential have only been seen as teenagers, after star formation had begun,” said Johnson. “That meant that the nursery had already been disturbed. To understand how a globular cluster forms, you need to see its true beginnings.”

    Most globular clusters formed during a veritable “baby boom” around 12 billion years ago, at a time when galaxies first assembled. Each contains as many as a million densely packed “second generation” stars — stars with conspicuously low concentrations of heavy metals, indicating they formed very early in the history of the universe. Our own Milky Way is known to have at least 150 such clusters, though it may have many more.

    Throughout the universe, star clusters of various sizes are still forming to this day. It’s possible, though increasingly rare, that the largest and densest of these will go on to become globular clusters.

    “The survival rate for a massive young star cluster to remain intact is very low – around one percent,” said Johnson. “Various external and internal forces pull these objects apart, either forming open clusters like the Pleiades or completely disintegrating to become part of a galaxy’s halo.”

    The astronomers believe, however, that the object they observed with ALMA, which contains 50 million times the mass of the Sun in molecular gas, is sufficiently dense that it has a good chance of being one of the lucky ones.


    Animation of ALMA data depicting dense cores of molecular gas in the Antennae galaxies. The yellow object at the center may be the first prenatal example of a globular cluster ever identified. Credit: K. Johnson, U.Va.; ALMA (NRAO/ESO/NAOJ)

    Globular clusters evolve out of their embryonic, star-free stage very rapidly — in as little as one million years. This means the object discovered by ALMA is undergoing a very special phase of its life, offering astronomers a unique opportunity to study a major component of the early universe.

    The ALMA data also indicate that the Firecracker cloud is under extreme pressure – approximately 10,000 times greater than typical interstellar pressures. This supports previous theories that high pressures are required to form globular clusters.

    In exploring the Antennae, Johnson and her colleagues observed the faint emission from carbon monoxide molecules, which allowed them to image and characterize individual clouds of dust and gas. The lack of any appreciable thermal emission – the telltale signal given off by gas heated by nearby stars – confirms that this newly discovered object is still in its pristine, unaltered state.

    Further studies with ALMA may reveal additional examples of proto super star clusters in the Antennae galaxies and other interacting galaxies, shedding light on the origins of these ancient objects and the role they play in galactic evolution.

    More Information

    The paper The Physical Conditions in a Pre Super Star Cluster Molecular Cloud in the Antennae Galaxies by K.E. Johnson et.al it can be found here.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

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

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

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  • richardmitnick 2:12 pm on April 29, 2015 Permalink | Reply
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    From ALMA: “Launch of ChiVO, the first Chilean Virtual Observatory” 

    ESO ALMA Array
    ALMA

    24 April 2015
    Valeria Foncea
    Education and Public Outreach Officer
    Joint ALMA Observatory
    Santiago, Chile
    Tel: +56 2 467 6258
    Cell: +56 9 75871963
    Email: vfoncea@alma.cl

    1

    After more than two years of work, today was launched the first Chilean Virtual Observatory (ChiVO), an astro-informatic platform for the administration and analysis of massive data coming from the observatories built across the country. Its implementation will provide advanced computing tools and research algorithms to the Chilean astronomical community.

    3
    The project designed to manage and analyze the almost 250 terabytes of data that the Atacama Millimeter/submillimeter Array (ALMA) will generate each year has joined the International Virtual Observatory Alliance, becoming a key initiative in Chile’s contribution to astroinformatics around the world.

    4

    “This project is a major contribution for Chilean astronomers -said Diego Mardones, an astronomer at Universidad de Chile- because besides being an excellent tool for exploring the huge quantity of astronomical data that will be generated in our country in the coming years, it opens new opportunities of interdisciplinary research.”

    2
    ChiVO main team. Left to right: Paulina Troncoso, Astronomer; Ricardo Contreras, U. of Concepción; Jorge Ibsen, ALMA; Mauricio Solar, ChiVO’s director, U. Técnica Federico Santa María (UFSM); Paola Arellano, REUNA; Victor Parada, U. of Santiago; Marcelo Mendoza, ChiVO’s alternate director, UFSM; Diego Mardones, U. of Chile; Mauricio Araya, UFSM; María; Guillermo Cabrera, U. of Chile.

    The project led by Universidad Técnica Federico Santa María (UTFSM) is a successful collaboration with four other universities in Chile (Universidad de Chile, Universidad Católica, Universidad de Concepción y Universidad de Santiago) and was funded by FONDEF, the Chilean Scientific and Technological Development Fund. Furthermore, both the Atacama Large Millimeter/submillimeter Array (ALMA) and REUNA, the National Universities Network, are associated to the project. Thanks to ChiVO, Chile will become a member of the International Virtual Observatories Alliance (IVOA) and it will be accessible for all astronomers making their research in the country through its website http://www.chivo.cl.

    For the project’s director, Mauricio Solar, “this innovation will allow astronomical data to be processed in Chile using high-quality, local human capital and integrating Chilean astro-informatics with the international community at the highest levels of development.”

    With new telescopes being constructed in Chile, the amount of astronomical data generated will only increase. As an example, once ALMA is operating at full capacity, it will produce close to 250 terabytes of data each year. ChiVO will enable Chilean astronomers to access this data with high transfer rates, provide the infrastructure for high storage capacity and access the analysis of the data.

    “ChiVO and the services provided by it will be a key tool for the Chilean astronomical community, added Jorge Ibsen, director of ALMA’s Department of Computing. “ALMA is proud to be part of this project that will boost the usage of the astronomical data generated in the country.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

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

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

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  • richardmitnick 1:32 pm on April 16, 2015 Permalink | Reply
    Tags: ALMA, , , ,   

    From ALMA: “ALMA Reveals Intense Magnetic Field Close to Supermassive Black Hole” 

    ESO ALMA Array
    ALMA

    16 April 2015
    Valeria Foncea
    Education and Public Outreach Officer
    Joint ALMA Observatory
    Santiago, Chile
    Tel: +56 2 467 6258
    Cell: +56 9 75871963
    Email: vfoncea@alma.cl

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

    Charles E. Blue
    Public Information Officer
    National Radio Astronomy Observatory
    Charlottesville, Virginia, USA
    Tel: +1 434 296 0314
    Cell: +1 434.242.9559
    E-mail: cblue@nrao.edu

    Masaaki Hiramatsu
    Education and Public Outreach Officer, NAOJ Chile
    Observatory Tokyo, Japan
    Tel: +81 422 34 3630
    E-mail: hiramatsu.masaaki@nao.ac.jp

    1
    This artist’s impression shows the surroundings of a supermassive black hole, typical of that found at the heart of many galaxies. The black hole itself is surrounded by a brilliant accretion disc of very hot, infalling material and, further out, a dusty torus. There are also often high-speed jets of material ejected at the black hole’s poles that can extend huge distances into space. Observations with ALMA have detected a very strong magnetic field close to the black hole at the base of the jets and this is probably involved in jet production and collimation.

    The Atacama Large Millimeter/submillimeter Array (ALMA) has revealed an extremely powerful magnetic field, beyond anything previously detected in the core of a galaxy, very close to the event horizon of a supermassive black hole. This new observation helps astronomers to understand the structure and formation of these massive inhabitants of the centres of galaxies, and the twin high-speed jets of plasma they frequently eject from their poles. The results appear in the 17 April 2015 issue of the journal Science.

    Supermassive black holes, often with masses billions of times that of the Sun, are located at the heart of almost all galaxies in the Universe. These black holes can accrete huge amounts of matter in the form of a surrounding disc. While most of this matter is fed into the black hole, some can escape moments before capture and be flung out into space at close to the speed of light as part of a jet of plasma. How this happens is not well understood, although it is thought that strong magnetic fields, acting very close to the event horizon, play a crucial part in this process, helping the matter to escape from the gaping jaws of darkness.

    Up to now only weak magnetic fields far from black holes — several light-years away — had been probed [1]. In this study, however, astronomers from Chalmers University of Technology and Onsala Space Observatory in Sweden have now used ALMA to detect signals directly related to a strong magnetic field very close to the event horizon of the supermassive black hole in a distant galaxy named PKS 1830-211. This magnetic field is located precisely at the place where matter is suddenly boosted away from the black hole in the form of a jet.

    The team measured the strength of the magnetic field by studying the way in which light was polarised, as it moved away from the black hole.

    “Polarisation is an important property of light and is much used in daily life, for example in sun glasses or 3D glasses at the cinema,” says Ivan Marti-Vidal, lead author of this work. “When produced naturally, polarisation can be used to measure magnetic fields, since light changes its polarisation when it travels through a magnetised medium. In this case, the light that we detected with ALMA had been travelling through material very close to the black hole, a place full of highly magnetised plasma.”

    The astronomers applied a new analysis technique that they had developed to the ALMA data and found that the direction of polarisation of the radiation coming from the centre of PKS 1830-211 had rotated [2]. These are the shortest wavelengths ever used in this kind of study, which allow the regions very close to the central black hole to be probed [3].

    “We have found clear signals of polarisation rotation that are hundreds of times higher than the highest ever found in the Universe,” says Sebastien Muller, co-author of the paper. “Our discovery is a giant leap in terms of observing frequency, thanks to the use of ALMA, and in terms of distance to the black hole where the magnetic field has been probed — of the order of only a few light-days from the event horizon. These results, and future studies, will help us understand what is really going on in the immediate vicinity of supermassive black holes.”

    Notes

    [1] Much weaker magnetic fields have been detected in the vicinity of the relatively inactive supermassive black hole at the centre of the Milky Way. Recent observations have also revealed weak magnetic fields in the active galaxy NGC 1275, which were detected at millimetre wavelengths.

    [2] Magnetic fields introduce Faraday rotation, which makes the polarisation rotate in different ways at different wavelengths. The way in which this rotation depends on the wavelength tells us about the magnetic field in the region.

    [3] The ALMA observations were at an effective wavelength of about 0.3 millimetres, earlier investigations were at much longer radio wavelengths. Only light of millimetre wavelengths can escape from the region very close to the black hole, longer wavelength radiation is absorbed.

    More Information

    This research was presented in a paper entitled “A strong magnetic field in the jet base of a supermassive black hole” to appear in Science on 16 April 2015.

    The team is composed of I. Martí-Vidal (Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, Onsala, Sweden), S. Muller (Onsala Space Observatory), W. Vlemmings (Onsala Space Observatory), C. Horellou (Onsala Space Observatory), S. Aalto (Onsala Space Observatory).

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

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

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

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  • richardmitnick 10:50 am on April 8, 2015 Permalink | Reply
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    From ALMA: “Complex Organic Molecules Discovered in Infant Star System: Hints that Prebiotic Chemistry Is Universal “ 

    ESO ALMA Array
    ALMA

    Wednesday, 08 April 2015
    Valeria Foncea
    Education and Public Outreach Officer
    Joint ALMA Observatory
    Santiago, Chile
    Tel: +56 2 467 6258
    Cell: +56 9 75871963
    Email: vfoncea@alma.cl

    Charles E. Blue
    Public Information Officer
    National Radio Astronomy Observatory
    Charlottesville, Virginia, USA
    Tel: +1 434 296 0314
    Cell: +1 434.242.9559
    E-mail: cblue@nrao.edu

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

    Masaaki Hiramatsu
    Education and Public Outreach Officer, NAOJ Chile
    Observatory Tokyo, Japan
    Tel: +81 422 34 3630
    E-mail: hiramatsu.masaaki@nao.ac.jp

    1
    Artist impression of the protoplanetary disk surrounding the young star MWC 480. ALMA has detected the complex organic molecule methyl cyanide in the outer reaches of the disk in the region where comets are believed to form. This is another indication that complex organic chemistry, and potentially the conditions necessary for life, is universal. Credit: B. Saxton (NRAO/AUI/NSF)

    For the first time, astronomers have detected the presence of complex organic molecules, the building blocks of life, in a protoplanetary disk surrounding a young star, suggesting once again that the conditions that spawned our Earth and Sun are not unique in the Universe.

    This discovery, made with the Atacama Large Millimeter/submillimeter Array (ALMA), reveals that the protoplanetary disk surrounding the million-year-old star MWC 480 is brimming with methyl cyanide (CH3CN), a complex carbon-based molecule. Both this molecule and its simpler cousin hydrogen cyanide (HCN) were found in the cold outer reaches of the star’s newly formed disk, in a region that astronomers believe is analogous to our own Kuiper Belt — the realm of icy planetesimals and comets beyond Neptune.

    2
    Known objects in the Kuiper belt beyond the orbit of Neptune (scale in AU; epoch as of January 2015).

    Scientists understand that comets retain a pristine record of the early chemistry of our solar system from the period of planet formation. As the planets evolved, it’s believed that comets and asteroids from the outer solar system seeded the young Earth with water and organic molecules, helping set the stage for life to eventually emerge.

    “Studies of comets and asteroids show that the solar nebula that spawned our Sun and planets was rich in water and complex organic compounds,” noted Karin Öberg, an astronomer with the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., and lead author on a paper published in the journal Nature. “We now have evidence that this same chemistry exists elsewhere in the universe, in regions that could form solar systems not unlike our own.” This is particularly intriguing, Öberg notes, since the molecules found in MWC 480 are also found in similar concentrations in our own solar system’s comets.

    The star MWC 480, which is about twice the mass of the Sun, is located approximately 455 light-years away in the Taurus star-forming region. Its surrounding disk is in the very early stages of development – having recently coalesced out of a cold, dark nebula of dust and gas. Studies with ALMA and other telescopes have yet to detect any obvious signs of planet formation in it, though higher resolution observations may reveal structures similar to HL Tau, which is of a similar age.

    Astronomers have known that cold, dark interstellar clouds are very efficient factories of complex organic molecules — including a group of molecules known as cyanides. Cyanides, and most especially methyl cyanide, are important because they contain carbon-nitrogen bonds, which are essential for the formation of amino acids, the foundation of proteins.

    It has been unclear, however, if these same complex organic molecules commonly form and survive in the energetic environment of a newly forming solar system, where shocks and radiation can easily break chemical bonds.

    With ALMA’s remarkable sensitivity, the astronomers now know that these molecules not only survive, but thrive.

    Importantly, the molecules ALMA detected are much more abundant than would be found in interstellar clouds. According to the researchers, there’s enough methyl cyanide around MWC 480 to fill all of Earth’s oceans. This tells astronomers that protoplanetary disks are very efficient at forming complex organic molecules and that they are able to form them on a relatively fast timescale.

    This rapid formation is essential to outpace the forces that would otherwise break the molecules apart. Also, these molecules were detected in a relatively serene part of the disk, roughly 4.5 to 15 billion kilometers from the central star. Though incredibly distant by our solar system’s standards, in MWC 480’s scaled-up dimensions, this would be squarely in the comet-forming zone.

    As this solar system continues to evolve, astronomers speculate, it’s likely that the organic molecules safely locked away in comets and other icy bodies will be ferried to environments that would be more nurturing for life.

    “From the study of exoplanets, we know our solar system isn’t unique in having rocky planets and an abundance of water,” concluded Öberg. “Now we know we’re not unique in organic chemistry. Once more, we have learned that we’re not special. From a life in the universe point of view, this is great news.”

    ALMA is the world’s most sophisticated and powerful telescope of its kind. It is able to detect the faint millimeter wavelength radiation that is naturally emitted by molecules in space. For these most recent observations, the astronomers used only a portion of ALMA’s 66 antennas when the telescope was in its lower-resolution configuration. Further studies of this and other protoplanetary disks with ALMA’s full capabilities will reveal additional details about the chemical and structural evolution of stars and planets.

    More information

    The paper “The cometary composition of a protoplanetary disk as revealed by complex cyanides” is located here.

    See the full article here.

    [There will be a separate blog post on this find from ESO, as soon as it released.]

    Please help promote STEM in your local schools.

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

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

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  • richardmitnick 12:34 pm on April 7, 2015 Permalink | Reply
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    From ALMA: “ALMA Partnership Publishes First Results on Long Baselines” 

    ESO ALMA Array
    ALMA

    Tuesday, 07 April 2015
    Valeria Foncea
    Education and Public Outreach Officer
    Joint ALMA Observatory
    Santiago, Chile
    Tel: +56 2 467 6258
    Cell: +56 9 75871963
    Email: vfoncea@alma.cl

    Charles E. Blue
    Public Information Officer
    National Radio Astronomy Observatory
    Charlottesville, Virginia, USA
    Tel: +1 434 296 0314
    Cell: +1 434.242.9559
    E-mail: cblue@nrao.edu

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

    Masaaki Hiramatsu
    Education and Public Outreach Officer, NAOJ Chile
    Observatory Tokyo, Japan
    Tel: +81 422 34 3630
    E-mail: hiramatsu.masaaki@nao.ac.jp

    Unprecedented views of the surface of asteroid Juno and the Einstein Ring of a distant galaxy have recently been captured in images taken by the Atacama Large Millimeter/submillimeter Array (ALMA). These stunning images were taken at the end of 2014 as part of ALMA’s Long Baseline Campaign, with the goal of testing and verifying the telescope’s highest resolving power, achieved when the antennas are at their greatest separation: up to 15 kilometers apart.

    “It takes a combination of ALMA’s high resolution and high sensitivity to unlock these otherwise hidden details of the Universe,” said ALMA Director Pierre Cox.

    Five targets were selected for this ALMA Campaign, including asteroid Juno, the protoplanetary disk HL Tau, the gravitationally lensed galaxy SDP.81, the evolved star Mira, and the quasar 3C138. The Astrophysical Journal, Letters has published four scientific papers written by representatives of the entire international team of the ALMA Partnership, detailing these observations.

    The Long Baseline Campaign captured the highest resolution images ever taken with this state-of-the-art instrument, giving astronomers an unprecedented view of the distant galaxy SDP.81 that– seen from Earth with the aid of a gravitational lens — appears like a cosmic ring [image 1].

    1
    Image 1. ALMA image of the gravitationally lensed galaxy SDP.81. The bright orange central region of the ring (ALMA’s highest resolution observation ever) reveals the glowing dust in this distant galaxy. The surrounding lower-resolution portions of the ring trace the millimeter wavelength light emitted by carbon monoxide. Credit: ALMA (NRAO/ESO/NAOJ); B. Saxton NRAO/AUI/NSF |

    Forged by the chance alignment of two distant galaxies, the more distant one magnified by the gravitational pull of the intervening one located between the distant source and the Earth, SDP.81 is a gravitationally lensed object known as an Einstein Ring. A manifestation of [Albert] Einstein’s Theory of General Relativity, gravity acted like an optical lens, bending the light to magnify the image of the distant galaxy and producing a distorted arc-shaped image as seen from the Earth.

    “This is a major accomplishment for ALMA’s high-resolution capabilities,” said ALMA Deputy Program Scientist Catherine Vlahakis. These ALMA observations achieved a resolution as fine as 23 milliarcseconds, which is a first for telescopes that operate at these wavelengths, rivaling even the Hubble Space Telescope.

    NASA Hubble Telescope
    NASA/ESA Hubble

    Another series of images made with ALMA provided an unprecedented view of the surface of Juno, one of the largest members of our Solar System’s main asteroid belt. Linked together into a brief animation, these high-resolution images show the asteroid rotating through space as it shines in millimeter-wavelength light [image 2].

    2
    Image 2. Animation of the asteroid Juno as imaged by ALMA as part of the telescope’s Long Baseline Campaign. Images were taken when Juno was approximately 295 million kilometers from Earth. Credit: ALMA (NRAO/ESO/NAOJ)

    The complete ALMA observation was conducted over the course of four hours when Juno was approximately 295 million kilometers from Earth. For this observation, ALMA achieved a resolution of 40 milliarcseconds, meaning that each “pixel” in the images is about 60 kilometers across, covering approximately one-fourth of the surface of Juno. This resolution is a vast improvement over earlier observations made at similar wavelengths and is enough to clearly resolve the shape of the asteroid and potentially tease out prominent surface features.

    “This new observation clearly demonstrates that ALMA is a very powerful tool for studying asteroids and shows the ability to image the surface of many Solar System bodies better than any other instrument,” added ALMA astronomer Ed Fomalont.

    3
    Image 3. This image shows the protoplanetary disc surrounding the young star HL Tauri. These new ALMA observations reveal substructures within the disc that have never been seen before and even show the possible positions of planets forming in the dark patches within the system. Credit: ALMA (ESO/NAOJ/NRAO)

    Another target was the proto-planetary disc HL Tau, whose results observation represented an enormous step forward in the understanding of how these discs develop and how planets form.

    The five objects were chosen to show the scientific potential of ALMA, the world’s largest ground-based observatory, in its most extended configuration.

    More information

    The paper, ALMA Long Baseline Observations of the Strongly Lensed Submillimeter Galaxy HATLAS J090311.6+003906 at z=3.042, is located here: http://arxiv.org/abs/1503.02652

    The paper, ALMA Observations of Asteroid 3 Juno at 60 Kilometer Resolution, is located here: http://arxiv.org/pdf/1503.02650.pdf

    The paper, First Results From High Angular Resolution ALMA Observations Toward the HL Tau Region, is located here: http://arxiv.org/pdf/1503.02649.pdf

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

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

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

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  • richardmitnick 7:14 am on March 31, 2015 Permalink | Reply
    Tags: ALMA, , ,   

    From ALMA: “ALMA Disentangles Complex Birth of Giant Stars” 

    ESO ALMA Array
    ALMA

    31 March 2015
    Valeria Foncea
    Education and Public Outreach Officer
    Joint ALMA Observatory
    Santiago, Chile
    Tel: +56 2 467 6258
    Cell: +56 9 75871963
    Email: vfoncea@alma.cl

    Masaaki Hiramatsu
    Education and Public Outreach Officer, NAOJ Chile
    Observatory Tokyo, Japan
    Tel: +81 422 34 3630
    E-mail: hiramatsu.masaaki@nao.ac.jp

    Charles E. Blue
    Public Information Officer
    National Radio Astronomy Observatory
    Charlottesville, Virginia, USA
    Tel: +1 434 296 0314
    Cell: +1 434.242.9559
    E-mail: cblue@nrao.edu

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

    A research group led by Aya Higuchi, a researcher at Ibaraki University in Japan, conducted observations of the massive-star forming region IRAS 16547-4247 with the Atacama Large Millimeter/submillimeter Array (ALMA). The observation results shows the presence of multiple, or at least two, gas outflows from a protostar, indicating the possible existence of two new-born stars in this region. Also, the radio observation results of molecular line emission of methanol revealed in vivid detail an hourglass structure created by gas outflows spreading outward while thrusting the ambient gas cloud away. It is the first time that such an hourglass structure was found in observations of methanol in high-mass star forming regions. Detailed observations of high-mass stars have been considered difficult so far because high-mass stars form in a complex environment with multiple protostars in clusters, and their forming regions are located farther away from the Earth compared to those of low-mass stars. However, high angular resolution observations with ALMA opened a new window to understand their formation environment in further details.

    1
    An artist’s concept of the distribution of the ambient gas around IRAS 16547-4247. The central high-density gas cloud is thought to contain multiple high-density protostars. Two outflows of gas spurt from the central part in the vertical and horizontal directions respectively while pushing the ambient gas away, which makes a balloon-like structure. A pair of narrow jets is the one that was found in past observations.

    Research Background

    All stars that twinkle in the night sky vary in their masses. While some stars have masses smaller than 1/10 of solar masses, others have masses larger than 100 solar masses. How such a wide variety of stars are born and what factors make the difference in their masses; these are the most fundamental and most enigmatic astronomical questions, which have yet to be answered. To solve these mysteries, it is essential to make detailed observations of various stars of different masses during formation.

    The formation process of high-mass stars, which have masses larger than ten times solar mass still has much to be explored. Detailed observations of high-mass stars at an early stage of formation are difficult because the number of high-mass stars is smaller than that of one-solar-mass stars and the evolution process of high-mass stars is faster than low-mass stars [1]. Another adverse condition in the study of high-mass stars is the distance from the Earth; while the forming regions of low-mass stars are about 500 light years away from the Earth, those of high-mass stars are farther and even the closest one in the Orion Nebula is about 1500 light years away.

    4
    Orion
    In one of the most detailed astronomical images ever produced, NASA/ESA’s Hubble Space Telescope captured an unprecedented look at the Orion Nebula. … This extensive study took 105 Hubble orbits to complete. All imaging instruments aboard the telescope were used simultaneously to study Orion. The Advanced Camera mosaic covers approximately the apparent angular size of the full moon.

    NASA Hubble Telescope
    NASA/ESA Hubble

    Since it is thought that high-mass stars are born in clusters far away from the Earth, it is impossible to understand their formation process in detail without high angular resolution observations. In this regard, ALMA is the most desirable telescope for this purpose as being capable of observing gas and dust, which will be ingredients of stars at high sensitivity and high resolution.

    2
    A mesh 3D model of gas distribution. The orange-colored, peanut-hull-like structure at the center represents the high-density gas cloud observed with ALMA; the blue-colored, big rugby-ball-like structure stretching out in the vertical direction represents the big outflow observed in past observations; and the lime-green-colored and purple-colored structures represent the outflows discovered with ALMA.

    Observations with ALMA

    The research team led by Aya Higuchi made observations of the luminous infrared source IRAS 16547-4247 in the direction of the Scorpion. IRAS 16547-4247 is an object emitting strong radiation with about 60 times solar luminosity and being surrounded by high-density molecular cloud with a mass of 1300 times solar mass in a distance of 9500 light years away from the Earth. Past radio observations of molecular carbon monoxide (CO) in this region revealed a pair of outflows, which was thought to be emitted from a young star, and some other radio sources have been found in addition to a bright object at the center. “Even though many of the astronomers assumed that this would be a fertile high-mass star forming region, we couldn’t probe the kinematics of gas around high-mass protostars at the level of resolution provided by existing telescopes,” Higuchi said.

    To study the structure and kinematics of gas around IRAS 16547-4247, the research group observed molecular line emission of dust, CO, and methanol (CH3OH). From the observation results of dust, it was first found that the center of the region contains two high-density compact gas clouds with masses 10 to 20 times solar mass. It is thought that these gas clouds are surrounding a newly forming high-mass star like a cocoon.

    3
    An artist’s concept of the distribution of the ambient gas around IRAS 16547-4247. The central high-density gas cloud is thought to contain multiple high-density protostars. Two outflows of gas spurt from the central part in the vertical and horizontal directions respectively while pushing the ambient gas away, which makes a balloon-like structure. A pair of narrow jets is the one that was found in past observations.

    And the observation results of CO indicates that the outflows which looked like a blurred object extending in the north-south direction was actually two pairs of outflows aligned with the north-south and east-west direction respectively. Furthermore, new high-velocity outflows have also been found in the observations. Since the angular resolution provided by ALMA was 36 times higher than that applied to the past CO observations, the observation results clearly revealed the details of complex structure and kinematics of gas. As it is assumed that one protostar is able to produce only a pair of outflows, these results suggests that multiple stars are being formed simultaneously in this region.

    On top of these, the research group discovered that methanol molecule is spreading from the center of IRAS1654-4247 in the form of hourglass structure. CH3OH is normally produced on the surface of dust, but when the temperature increases by some process, it will be released from the dust surface and turn into gas, which emits radio waves.

    Since the hourglass structure made by the distribution of CH3OH traces the contour of the observed CO outflow, CH3OH is assumed to have been produced by the interaction with the ambient gas, which was pushed away by the outflow from the protostar, resulting in the increase of temperature and consequent transition into gas. This kind of hourglass structure has often been found around low-mass protostars, but it was the first time that the distribution of CH3OH with this structure was found in a high-mass-star forming region. Furthermore, past observation results indicates the presence of a maser source [2] emitting extremely strong radio waves on the extended line of the CO outflow. Although it was unknown what is responsible for the maser source in this object, the observation results this time suggests that the maser source is excited by the shock influence between a high-velocity outflow and the ambient gas.

    “We conducted radio observations of carbon monoxide and methanol to explore the details of the distribution and kinematics of gas in the region where high-mass stars are forming in clusters,” Higuchi said. “A typical example of a high-mass star forming region is the Orion Nebula, but ALMA enabled us to see the complex formation environment of star clusters which is even 7 times farther away than the Orion Nebula with the highest imaging resolution ever achieved. ALMA will become indispensable for the future research on the high-mass star forming region.”

    Notes

    [1] The formation of high-mass stars completes over the course of a hundred thousand years, which is approximately one tenth of the formation period of low-mass stars.

    [2] Maser is a phenomenon that emits strong electromagnetic radiation of a coherent wavelength. Laser used in our daily life is also strong radiation produced on the same principle applied to maser. Since maser is produced when atoms are excited to a high-energy state, the presence of a maser source suggests the possibility of a physical state, which is different from that of common interstellar cloud.

    More information

    These observation results were published as Higuchi et al. IRAS 16547-4247: A New Candidate of a Protocluster Unveiled with ALMA in the astronomical journal Astrophysical Journal Letters, issued in January 2015.

    This research was conducted by: Aya Higuchi (Ibaraki University); Kazuya Saigo (National Astronomical Observatory of Japan); James Chibueze (National Astronomical Observatory of Japan/University of Nigeria); Patricio Sanhueza (National Astronomical Observatory of Japan); Shigehisa Takakuwa (Academia Sinica Institute of Astronomy and Astrophysics), and Guido Garay (University of Chile)

    This research is supported by Grant-in-Aid for Scientific Research on Innovative Areas “New Frontiers of Extrasolar Planets: Exploring Terrestrial Planets”. Guide Garay is supported by CONICYT project PFB-06.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

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

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

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  • richardmitnick 4:17 pm on March 5, 2015 Permalink | Reply
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    From ALMA: “ALMA Gains New Capability in its First VLBI Observation “ 

    ESO ALMA Array
    ALMA

    Thursday, 05 March 2015
    Contact:

    Valeria Foncea
    Education and Public Outreach Officer
    Joint ALMA Observatory
    Santiago, Chile
    Tel: +56 2 467 6258
    Cell: +56 9 75871963
    Email: vfoncea@alma.cl

    Charles E. Blue
    Public Information Officer
    National Radio Astronomy Observatory
    Charlottesville, Virginia, USA
    Tel: +1 434 296 0314
    Cell: +1 434.242.9559
    E-mail: cblue@nrao.edu

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

    Masaaki Hiramatsu
    Education and Public Outreach Officer, NAOJ Chile
    Observatory Tokyo, Japan
    Tel: +81 422 34 3630
    E-mail: hiramatsu.masaaki@nao.ac.jp

    1
    ALMA, the Atacama Large Millimeter/submillimeter Array, has successfully combined its immense collecting area and sensitivity with that of APEX (Atacama Pathfinder Experiment) to create a new, single instrument through a process known as Very Long Baseline Interferometry (VLBI). This first successful observation using VLBI with ALMA used a baseline of 2.1 km, and was an essential proof-of-concept test for the planned Event Horizon Telescope, which eventually will include a global network of millimetre-wavelength telescopes. Crédito: Clem & Adri Bacri-Normier (wingsforscience.com)/ESO

    The Atacama Large Millimeter/submillimeter Array (ALMA) recently combined its immense collecting area and sensitivity with that of the APEX (Atacama Pathfinder Experiment) Telescope to create a new, single instrument through a process known as Very Long Baseline Interferometry (VLBI). In VLBI, data from two independent telescopes are combined to form a virtual telescope that spans the geographic distance between them, yielding extraordinary magnifying power.

    ESO APEX
    ESO/APEX

    The new ALMA/APEX observation, which took place on January 13, was an essential proof-of-concept test for the planned Event Horizon Telescope (EHT), which eventually will include a global network of millimeter-wavelength telescopes.

    Event Horizon Telescope
    EHT

    When fully assembled, the EHT – with ALMA as the largest and most sensitive site – will form an Earth-size telescope with the magnifying power required to see details at the edge of the supermassive black hole at the center of the Milky Way.

    For this first-of-its-kind observation, ALMA and the nearby APEX telescope simultaneous studied a quasar known as 0522-364 – a distant galaxy commonly used for testing in radio astronomy due to its remarkable brightness. To ensure the telescopes were in sync, ALMA used its newly installed and exquisitely precise atomic clock (see ALMA announcement) to time-code the data as it was collected. This is essential for VLBI because it enables data taken at different geographical locations on different telescopes to be precisely matched and accurately integrated.

    The full dataset from the observing run was captured on hard drives and flown back to MIT where it will undergo full analysis. Due to the vast amount of information collected, air travel is the fastest means of data transmission, even faster than the fastest international Internet connection.

    “The entire team is immensely gratified at achieving this success on the first VLBI attempt with ALMA. It marks a huge step toward making first images of a black hole with the Event Horizon Telescope,” said Shep Doeleman, the principal investigator of the ALMA Phasing Project and assistant director of the Massachusetts Institute of Technology’s Haystack Observatory.

    This most recent work was carried out by a team made up of members from the ALMA Phasing Project, the Joint ALMA Observatory, the Smithsonian Astrophysical Observatory and the APEX Telescope.

    See the full article here.

    Please help promote STEM in your local schools.
    STEM Icon
    Stem Education Coalition

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

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

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  • richardmitnick 7:24 pm on March 2, 2015 Permalink | Reply
    Tags: ALMA, , , , Infrared Astronomy,   

    From ESO And ALMA: “An Old-looking Galaxy in a Young Universe” 

    ESO ALMA Array
    ESO/NRAO/NAOJ/ALMA
    ALMA


    European Southern Observatory

    ESO VLT Interferometer
    ESO/VLT

    2 March 2015

    Valeria Foncea
    Education and Public Outreach Officer
    Joint ALMA Observatory
    Santiago, Chile
    Tel: +56 2 467 6258
    Cell: +56 9 75871963
    Email: vfoncea@alma.cl

    Masaaki Hiramatsu
    Education and Public Outreach Officer, NAOJ Chile
    Observatory Tokyo, Japan
    Tel: +81 422 34 3630
    E-mail: hiramatsu.masaaki@nao.ac.jp

    Charles E. Blue
    Public Information Officer
    National Radio Astronomy Observatory
    Charlottesville, Virginia, USA
    Tel: +1 434 296 0314
    Cell: +1 434.242.9559
    E-mail: cblue@nrao.edu

    Darach Watson
    Niels Bohr Institute
    University of Copenhagen, Denmark
    Tel: +45 2480 3825
    Email: darach@dark-cosmology.dk

    Kirsten K. Knudsen
    Chalmers University of Technology
    Onsala, Sweden
    Tel: +46 31 772 5526
    Cell: +46 709 750 956
    Email: kirsten.knudsen@chalmers.se

    Richard Hook
    ESO education and Public Outreach Department
    Garching bei München, Germany
    Tel: +49 89 3200 6655
    Cell: +49 151 1537 3591
    Email: rhook@eso.org

    temp0

    One of the most distant galaxies ever observed has provided astronomers with the first detection of dust in such a remote star-forming system and tantalising evidence for the rapid evolution of galaxies after the Big Bang. The new observations have used ALMA to pick up the faint glow from cold dust in the galaxy A1689-zD1 and used ESO’s Very Large Telescope to measure its distance.

    A team of astronomers, led by Darach Watson from the University of Copenhagen, used the Very Large Telescope’s X-shooter instrument along with the Atacama Large Millimeter/submillimeter Array (ALMA) to observe one of the youngest and most remote galaxies ever found.

    ESO VLT X-shooter
    X-shooter

    They were surprised to discover a far more evolved system than expected. It had a fraction of dust similar to a very mature galaxy, such as the Milky Way. Such dust is vital to life, because it helps form planets, complex molecules and normal stars.

    The target of their observations is called A1689-zD1 [1]. It is observable only by virtue of its brightness being amplified more than nine times by a gravitational lens in the form of the spectacular galaxy cluster, Abell 1689, which lies between the young galaxy and the Earth. Without the gravitational boost, the glow from this very faint galaxy would have been too weak to detect.

    We are seeing A1689-zD1 when the Universe was only about 700 million years old — five percent of its present age [2]. It is a relatively modest system — much less massive and luminous than many other objects that have been studied before at this stage in the early Universe and hence a more typical example of a galaxy at that time.

    8

    A1689-zD1 is being observed as it was during the period of reionisation, when the earliest stars brought with them a cosmic dawn, illuminating for the first time an immense and transparent Universe and ending the extended stagnation of the [cosmic] Dark Ages. Expected to look like a newly formed system, the galaxy surprised the observers with its rich chemical complexity and abundance of interstellar dust.

    “After confirming the galaxy’s distance using the VLT,” said Darach Watson, “we realised it had previously been observed with ALMA. We didn’t expect to find much, but I can tell you we were all quite excited when we realised that not only had ALMA observed it, but that there was a clear detection. One of the main goals of the ALMA Observatory was to find galaxies in the early Universe from their cold gas and dust emissions — and here we had it!”

    This galaxy was a cosmic infant — but it proved to be precocious. At this age it would be expected to display a lack of heavier chemical elements — anything heavier than hydrogen and helium, defined in astronomy as metals. These are produced in the bellies of stars and scattered far and wide once the stars explode or otherwise perish. This process needs to be repeated for many stellar generations to produce a significant abundance of the heavier elements such as carbon, oxygen and nitrogen.

    Surprisingly, the galaxy A1689-zD1 seemed to be emitting a lot of radiation in the far infrared [3], indicating that it had already produced many of its stars and significant quantities of metals, and revealed that it not only contained dust, but had a dust-to-gas ratio that was similar to that of much more mature galaxies.

    “Although the exact origin of galactic dust remains obscure,” explains Darach Watson, “our findings indicate that its production occurs very rapidly, within only 500 million years of the beginning of star formation in the Universe — a very short cosmological time frame, given that most stars live for billions of years.”

    The findings suggest A1689-zD1 to have been consistently forming stars at a moderate rate since 560 million years after the Big Bang, or else to have passed through its period of extreme starburst very rapidly before entering a declining state of star formation.

    Prior to this result, there had been concerns among astronomers that such distant galaxies would not be detectable in this way, but A1689-zD1 was detected using only brief observations with ALMA.

    Kirsten Knudsen (Chalmers University of Technology, Sweden), co-author of the paper, added, “This amazingly dusty galaxy seems to have been in a rush to make its first generations of stars. In the future, ALMA will be able to help us to find more galaxies like this, and learn just what makes them so keen to grow up.”
    Notes

    [1] This galaxy was noticed earlier in the Hubble images, and suspected to be very distant, but the distance could not be confirmed at that time.

    [2] This corresponds to a redshift of 7.5.

    [3] This radiation is stretched by the expansion of the Universe into the millimetre wavelength range by the time it gets to Earth and hence can be detected with ALMA.
    More information

    This research was presented in a paper entitled A dusty, normal galaxy in the epoch of reionization by D. Watson et al., to appear online in the journal Nature on 2 March 2015.

    The team is composed of D. Watson (Niels Bohr Institute, University of Copenhagen, Denmark), L. Christensen (University of Copenhagen), K. K. Knudsen (Chalmers University of Technology, Sweden), J. Richard (CRAL, Observatoire de Lyon, Saint Genis Laval, France), A. Gallazzi (INAF-Osservatorio Astrofisico di Arcetri, Firenze, Italy) and M. J. Michalowski (SUPA, Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh, UK).

    See the full article here.

    Hubble’s results

    2
    Abell 1689
    This new Hubble image shows galaxy cluster Abell 1689. It combines both visible and infrared data from Hubble’s Advanced Camera for Surveys (ACS) with a combined exposure time of over 34 hours (image on left over 13 hours, image on right over 20 hours) to reveal this patch of sky in greater and striking detail than in previous observations.

    This image is peppered with glowing golden clumps, bright stars, and distant, ethereal spiral galaxies. Material from some of these galaxies is being stripped away, giving the impression that the galaxy is dripping, or bleeding, into the surrounding space. Also visible are a number of electric blue streaks, circling and arcing around the fuzzy galaxies in the centre.
    These streaks are the telltale signs of a cosmic phenomenon known as gravitational lensing. Abell 1689 is so massive that it bends and warps the space around it, affecting how light from objects behind the cluster travels through space. These streaks are the distorted forms of galaxies that lie behind the cluster.
    Date 12 September 2013
    NASA, ESA, the Hubble Heritage Team (STScI/AURA), J. Blakeslee (NRC Herzberg Astrophysics Program, Dominion Astrophysical Observatory), and H. Ford (JHU)

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    ESO, European Southern Observatory, builds and operates a suite of the world’s most advanced ground-based astronomical telescopes.

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

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

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  • richardmitnick 8:31 am on February 26, 2015 Permalink | Reply
    Tags: ALMA, , ,   

    From ALMA: “ALMA Revealed Calm Pockets Protecting Organic Molecules” 

    ESO ALMA Array
    ALMA

    Thursday, 26 February 2015
    Nicolás Lira
    Education and Public Outreach Assistant
    Joint ALMA Observatory
    Santiago, Chile
    Tel: +56 2 467 6519
    Cell: +56 9 9445 7726
    Email: nlira@alma.cl

    Masaaki Hiramatsu
    Education and Public Outreach Officer, NAOJ Chile
    Observatory Tokyo, Japan
    Tel: +81 422 34 3630
    E-mail: hiramatsu.masaaki@nao.ac.jp

    Charles E. Blue
    Public Information Officer
    National Radio Astronomy Observatory
    Charlottesville, Virginia, USA
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    E-mail: cblue@nrao.edu

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    1
    The central part of the galaxy M77, also known as NGC 1068, observed by ALMA and the NASA/ESA Hubble Space Telescope. Yellow: cyanoacetylene (HC3N), Red: carbon monosulfide (CS), Blue: carbon monoxide (CO), which are observed with ALMA. While HC3N is abundant in the central part of the galaxy (CND), CO is mainly distributed in the starburst ring. CS is distributed both in the CND and the starburst ring. Credit: ALMA(ESO/NAOJ/NRAO), S. Takano et al., NASA/ESA Hubble Space Telescope

    NASA Hubble Telescope
    Hubble

    Researchers using the Atacama Large Millimeter/submillimeter Array (ALMA) have discovered regions where certain organic molecules somehow endure the intense radiation near the supermassive black hole at the center of galaxy NGC 1068, also known to amateur stargazers as M77.

    2
    Hubble Space Telescope image of NGC 1068

    Such complex carbon-based molecules are thought to be easily obliterated by the strong X-rays and ultraviolet (UV) photons that permeate the environment surrounding supermassive black holes. The new ALMA data indicate, however, that pockets of calm exist even in this tumultuous region, most likely due to dense areas of dust and gas that shield molecules from otherwise lethal radiation.

    Molecules Reveal Clues to Galactic Environments

    Interstellar gas contains a wide variety of molecules and its chemical composition differs widely depending on the environment. For example, an active star forming region with a temperature higher than the surrounding environment stimulates the production of certain types of molecules by chemical reactions which are difficult to take place in a cold temperature region. This enables researchers to probe the environment (temperature and density) of a target region by studying the molecular chemical compositions in it. Since each molecule has its own frequency spectrum, we can identify the chemical composition and the environment of a remote target object through observations with a radio telescope.

    From this perspective, astronomers have been actively working on the starburst regions of galaxies [1] and the surrounding region of the active galactic nuclei (AGN) at the center of galaxies, called circumnuclear disk (CND) [2]. These regions are very important in understanding the evolution of galaxies, and radio observations of molecular emissions are essential to explore its mechanism and environment [3]. However, the weak radio emission from molecules often made the observations difficult and took many days for signal detection using conventional radio telescopes.

    ALMA Observations Trace Molecules

    A research team led by Shuro Takano at the National Astronomical Observatory of Japan (NAOJ) and Taku Nakajima at Nagoya University observed the spiral galaxy M77 in the direction of the constellation of Cetus (the Whale) about 47 million light years away with ALMA. M77 is known to have an active galactic nucleus at its center which is surrounded by a starburst ring with a radius of 3500 light years.

    Since the research team had already conducted radio observations of various molecular emissions in this galaxy with the 45 meters telescope at the Nobeyama Radio Observatory of NAOJ, they aimed to develop their research further with ALMA’s extreme sensitivity, high-fidelity and ability to observe wideband in multiple wavelenght along with a high spatial resolution; and identify the difference in chemical composition between AGNs and starburst regions.

    NAOJ Nobeyama Radio Observatory
    Nobeyama Radio Observatory of NAOJ

    ALMA observations clearly revealed the distributions of nine types of molecules in the circumnuclear disk and in the starburst ring. “In this observation, we used only 16 antennas, which are about one-fourth of the complete number of ALMA antennas, but it was really surprising that we could get so many molecular distribution maps in less than two hours. We have never obtained such a quantity of maps in one observation,” says Takano, the leader of the research team.

    The results show that the molecular distribution varies according to the type of molecule. While carbon monoxide (CO) is distributed mainly in the starburst ring, five types of molecules, including complex organic molecules such as cyanoacetylene (HC3N) and acetonitrile (CH3CN) are concentrated in the circumnuclear disk. In addition, carbon monosulfide (CS) and methanol (CH3OH) are distributed both in the starburst ring and the circumnuclear disk. ALMA provided the first high resolution observation of the five types of molecules in M77 and revealed that they are concentrated in the circumnuclear disk.

    Shielding Complex Organics around a Black Hole

    The supermassive black hole devours surrounding materials by its strong gravity and generates such a hot disk around him that it emits intense X-rays or UV photons. When complex organic molecules are exposed to strong X-rays or UV photons, their multiple atomic bonds are broken and the molecules destroyed. This is why the circumnuclear disk was thought to be a very difficult environment for organic molecules to survive. ALMA observations, however, proved the contrary: Complex organic molecules are abundant in the circumnuclear disk.

    “It was quite unexpected that acetonitrile (CH3CN) and cyanoacetylene (HC3N), which have a large number of atoms, are concentrated in the circumnuclear disk,” said Nakajima.

    The research team assumes that organic molecules remain intact in the circumnuclear disk due to a large amount of gas, which act as a shield from X-rays and UV photons, while organic molecules cannot survive the exposure to the strong UV photons in the starburst region where the gas density is lower.

    The researchers point out that these results are a significant first step in understanding the structure, temperature, and density of gas surrounding the active black hole in M77. “We expect that future observations with wider bandwidth and higher resolution will show us the whole picture of our target object in further detail and achieve even more remarkable results,” says Takano.

    “ALMA has launched an entirely new era in astrochemistry,” said Eric Herbst of the University of Virginia in Charlottesville and a member of the research team. “Detecting and tracing molecules throughout the cosmos enables us to learn so much more about otherwise hidden areas, like the regions surrounding the black hole in M77.”

    These observation results were published as Takano et al. Distributions of molecules in the circumnuclear disk and surrounding starburst ring in the Seyfert galaxy NGC 1068 observed with ALMA (in the astronomical journal Publications of the Astronomical Society of Japan (PASJ), issued in July 2014) and as Nakajima et al. A Multi-Transition Study of Molecules toward NGC 1068 based on High-Resolution Imaging Observations with ALMA (in PASJ issued in February 2015).

    Notes

    [1] In the Milky Way Galaxy which we live in, one sun-like star is generated per year on average, while several hundred sun-like stars are churned out each year in a starburst region.

    [2] It is believed that most of the galaxies have in their center a supermassive black hole of millions to hundreds of millions of solar mass. Among them, Active Galactic Nuclei (AGN) represents a type of supermassive black hole which are gulping down surrounding gas very actively and emitting some amount of gas as high-speed gas flows (jets).

    [3] For example, a research team led by Takuma Izumi and Kotaro Kohno at the University of Tokyo, both of whom are engaged in this research, suggests that there is enhanced emission of hydrogen cyanide (HCN) from the supermassive black hole in the barred spiral galaxy NGC1097 by the past ALMA observations.

    Reference: October 24, 2013, Press release “Unique Chemical Composition Surrounding Supermassive Black Hole—A Step toward Development of New Black Hole Exploration Method”

    This research was conducted by: Shuro TAKANO (NAOJ Nobeyama Radio Observatory/SOKENDAI); Taku NAKAJIMA (Solar-Terrestrial Environment Laboratory, Nagoya University); Kotaro KOHNO (Institute of Astronomy, The University of Tokyo/Research Center for the Early Universe); Nanase HARADA (Academia Sinica Institute of Astronomy and Astrophysics [At the time of writing: Max Planck Institute for Radio Astronomy]); Eric HERBST (University of Virginia); Yoichi TAMURA (Institute of Astronomy, The University of Tokyo); Takuma IZUMI (Institute of Astronomy, The University of Tokyo); Akio TANIGUCHI (Institute of Astronomy, The University of Tokyo); Tomoka TOSAKI (Joetsu University of Educaction).

    See the full article here.

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

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

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