Tagged: Basic Research Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 8:30 pm on March 2, 2015 Permalink | Reply
    Tags: , Basic Research,   

    From SEN: “Massive exoplanet has extreme orbit around red giant” 

    SEN
    SEN

    28 February 2015
    Jenny Winder

    1

    Sen—Two groups of astronomers from Germany have, independently of each other, discovered an unusually dense and massive planet which orbits a red giant star.

    The teams, one led by Mauricio Ortiz of the Centre for Astronomy of Heidelberg University (ZAH), and the other by Simona Ciceri of the Max Planck Institute for Astronomy (MPIA) in the same city, report that Kepler-432b has six times the mass of Jupiter, but is about the same size, making it one of the most dense and massive exoplanets, a planet outside our Solar System, known so far.

    Kepler-432b was first noticed when NASA’s Kepler space telescope recorded tiny dips in the brightness of the planet’s host star, as the planet passed directly in front of the star, a “planetary transit”. The two Heidelberg teams were able to confirm the planet using the CAFE spectrograph at the 2.2-metre telescope at Calar Alto Observatory and the Nordic Optical Telescope on La Palma in the Canary Islands, to detect the planet’s traces in the spectrum of the star, the “radial velocity method”.

    Calar Alto Observatory
    2
    The 2.2 metre telescope at Calar Alto Observatory

    Nordic Optical Telescope
    Nordic Opitcal Telescope Interior
    Nordic Optical Telescope

    Only five planets, including Kepler-432b, have been observed which are unusually close to their red giant hosts. Of these, only two, namely Kepler-432b and Kepler-91b have been observed sufficiently closely to determine both their mass and their size

    Dr Davide Gandolfi, from the state observatory Königstuhl, told Sen: “The highly eccentric orbit brings Kepler-432b to ‘only’ 24 million km (15 million miles) from its host star, before taking it to about three times as far away. This creates enormous temperature differences over the course of the planet’s year, which is equivalent to 52 Earth days.

    “The majority of known planets moving around giant stars have large and circular orbits. With its small and highly elongated orbit, Kepler-432b is a real ‘maverick’ among planets of this type,” he added.

    The orbit of Kepler-432b is highly elongated. As a consequence, the distance between the planet and the star, as well as the temperature on the planet, change dramatically over the course of the planet’s year.

    3
    Illustration of the orbit of Kepler-432b (inner, red) in comparison to the orbit of Mercury around the Sun (outer, orange). Image credit: Dr Sabine Reffert

    “During the winter season, the temperature on Kepler-432b is roughly 500° Celsius. In the short summer season, it can increase to nearly 1,000° Celsius,” said astronomer Dr Sabine Reffert, also based at Königstuhl.

    Of the nearly 1,900 exoplanets known, around 50 orbit red giant stars, which are stars in the later stages of their lives. Kepler-432b’s parent star has already exhausted the nuclear fuel in its core and is gradually expanding. Its radius is already four times that of our Sun and it will get even larger in the future. Planets too close to such a star will be swallowed up, and planets orbiting too close to the red giant’s surface are likely to be drawn in and swallowed within tens or a few hundreds of million years.

    Astronomers do not expect to observe many examples of such a fairly short-lived phenomenon. Ciceri said. “At this point, there are two possibilities: Either we have been unusually lucky to observe two rare, close planetary orbits such as those of Kepler-432b and Kepler-91b. Or else, planets like these survive for much longer than was previously assumed.”

    Ortiz added: “The days of Kepler-432b are numbered. In less than 200 million years, Kepler-432b will be swallowed by its continually expanding host star. This might be the reason why we do not find other planets like Kepler-432b—astronomically speaking, their lives are extremely short”.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    The vision of Sen—space exploration network—is to create a global space content network. Sen provides space news and information on the science, economics and government of space and in so doing aims to:
    —promote interest in space;
    —raise awareness of the reality of humankind and Earth in the Universe, providing a different perspective to life on this planet;
    —educate and encourage consideration of the physics, economics and government of space;
    —create a community in which people can learn, debate and share information about space;
    —further the exploration of space;
    —film the universe forever building an electronic version of the universe, a never ending work of art, creating Sen Universe – a computerised to scale 3D universe, starting with the Solar System. Sen Universe will replace computer imagery with real film and imagery as our exploration of the universe continues, forever building an electronic version of the universe, a never ending work of art and science.
    —Ultimately, in achieving the above, Sen aims to be a business without boundary in space and time.

    Space is everything, it affects everything – it defines our environment, the government of mankind, relations, the future. By promoting interest and awareness of space a different perspective of our conduct and government of life on the planet can be obtained in the hope of creating a united planet.

    Sen will aim to be an enterprise that represents the best human effort at creating an enterprise without boundary in space and time.

     
  • richardmitnick 7:54 pm on March 2, 2015 Permalink | Reply
    Tags: Basic Research, , Light studies, ,   

    From EPFL: “The first ever photograph of light as both a particle and wave” 

    EPFL bloc

    Ecole Polytechnique Federale Lausanne

    1

    March 2, 2015

    Light behaves both as a particle and as a wave. Since the days of [Albert] Einstein, scientists have been trying to directly observe both of these aspects of light at the same time. Now, scientists at EPFL have succeeded in capturing the first-ever snapshot of this dual behavior.

    Quantum mechanics tells us that light can behave simultaneously as a particle or a wave. However, there has never been an experiment able to capture both natures of light at the same time; the closest we have come is seeing either wave or particle, but always at different times. Taking a radically different experimental approach, EPFL scientists have now been able to take the first ever snapshot of light behaving both as a wave and as a particle. The breakthrough work is published in Nature Communications.

    When UV light hits a metal surface, it causes an emission of electrons. Albert Einstein explained this “photoelectric” effect by proposing that light – thought to only be a wave – is also a stream of particles. Even though a variety of experiments have successfully observed both the particle- and wave-like behaviors of light, they have never been able to observe both at the same time.

    A research team led by Fabrizio Carbone at EPFL has now carried out an experiment with a clever twist: using electrons to image light. The researchers have captured, for the first time ever, a single snapshot of light behaving simultaneously as both a wave and a stream of particles particle.

    The experiment is set up like this: A pulse of laser light is fired at a tiny metallic nanowire. The laser adds energy to the charged particles in the nanowire, causing them to vibrate. Light travels along this tiny wire in two possible directions, like cars on a highway. When waves traveling in opposite directions meet each other they form a new wave that looks like it is standing in place. Here, this standing wave becomes the source of light for the experiment, radiating around the nanowire.

    This is where the experiment’s trick comes in: The scientists shot a stream of electrons close to the nanowire, using them to image the standing wave of light. As the electrons interacted with the confined light on the nanowire, they either sped up or slowed down. Using the ultrafast microscope to image the position where this change in speed occurred, Carbone’s team could now visualize the standing wave, which acts as a fingerprint of the wave-nature of light.

    While this phenomenon shows the wave-like nature of light, it simultaneously demonstrated its particle aspect as well. As the electrons pass close to the standing wave of light, they “hit” the light’s particles, the photons. As mentioned above, this affects their speed, making them move faster or slower. This change in speed appears as an exchange of energy “packets” (quanta) between electrons and photons. The very occurrence of these energy packets shows that the light on the nanowire behaves as a particle.

    “This experiment demonstrates that, for the first time ever, we can film quantum mechanics – and its paradoxical nature – directly,” says Fabrizio Carbone. In addition, the importance of this pioneering work can extend beyond fundamental science and to future technologies. As Carbone explains: “Being able to image and control quantum phenomena at the nanometer scale like this opens up a new route towards quantum computing.”

    This work represents a collaboration between the Laboratory for Ultrafast Microscopy and Electron Scattering of EPFL, the Department of Physics of Trinity College (US) and the Physical and Life Sciences Directorate of the Lawrence Livermore National Laboratory. The imaging was carried out EPFL’s ultrafast energy-filtered transmission electron microscope – one of the two in the world.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    EPFL is Europe’s most cosmopolitan technical university. It receives students, professors and staff from over 120 nationalities. With both a Swiss and international calling, it is therefore guided by a constant wish to open up; its missions of teaching, research and partnership impact various circles: universities and engineering schools, developing and emerging countries, secondary schools and gymnasiums, industry and economy, political circles and the general public.

     
  • richardmitnick 7:24 pm on March 2, 2015 Permalink | Reply
    Tags: , , Basic Research, , 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)

    NASA Hubble Telescope
    Hubble

    NASA Hubble ACS
    Hubble’s ACS

    Please help promote STEM in your local schools.
    STEM Icon

    Stem Education Coalition
    Visit ESO in Social Media-

    Facebook

    Twitter

    YouTube

    ESO Main

    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.

    NRAO Small

    ESO 50

    NAOJ

     
  • richardmitnick 6:01 am on March 2, 2015 Permalink | Reply
    Tags: , Basic Research,   

    From Hubble: “A young star takes centre stage” 

    NASA Hubble Telescope

    Hubble

    2 March 2015

    1
    Credit: NASA/ESA Hubble
    Karl Stapelfeldt (GSFC), B. Stecklum and A. Choudhary (Thüringer Landessternwarte Tautenburg, Germany)
    Hubble Space Telescope WFPC2

    NASA Hubble WFPC2

    With its helical appearance resembling a snail’s shell, this reflection nebula seems to spiral out from a luminous central star in this new NASA/ESA Hubble Space Telescope image.

    The star in the centre, known as V1331 Cyg and located in the dark cloud LDN 981 — or, more commonly, Lynds 981 — had previously been defined as a T Tauri star. A T Tauri is a young star — or Young Stellar Object — that is starting to contract to become a main sequence star similar to the Sun.

    What makes V1331Cyg special is the fact that we look almost exactly at one of its poles. Usually, the view of a young star is obscured by the dust from the circumstellar disc and the envelope that surround it. However, with V1331Cyg we are actually looking in the exact direction of a jet driven by the star that is clearing the dust and giving us this magnificent view.

    This view provides an almost undisturbed view of the star and its immediate surroundings allowing astronomers to study it in greater detail and look for features that might suggest the formation of a very low-mass object in the outer circumstellar disc.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

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

    ESA50 Logo large

    AURA Icon

     
  • richardmitnick 2:23 pm on March 1, 2015 Permalink | Reply
    Tags: Basic Research, ,   

    From Daily Galaxy: “Our Observed Universe is a Tiny Corner of an Enormous Cosmos –‘Ruled by Dark Energy'” 

    Daily Galaxy
    The Daily Galaxy

    March 01, 2015
    No Writer Credit

    1

    “This new concept is, potentially, as drastic an enlargement of our cosmic perspective as the shift from pre-Copernican ideas to the realization that the Earth is orbiting a typical star on the edge of the Milky Way.” Sir Martin Rees, physicist, Cambridge University, Astronomer Royal of Great Britain.

    Is our universe merely a part of an enormous universe containing diverse regions each with the right amount of the dark energy and each larger than the observed universe, according to Raphael Bousso, Professor of Theoretical Physics, U of California/Berkeley and Leonard Susskind, Felix Bloch Professor of Physics, Stanford University. The two theorize that information can leak from our causal patch into others, allowing our part of the universe to “decohere” into one state or another, resulting in the universe that we observe.

    The many worlds interpretation of quantum mechanics is the idea that all possible alternate histories of the universe actually exist. At every point in time, the universe splits into a multitude of existences in which every possible outcome of each quantum process actually happens.The reason many physicists love the many worlds idea is that it explains away all the strange paradoxes of quantum mechanics.

    Putting the many world interpretation aside for a moment, another strange idea in modern physics is the idea that our universe was born along with a large, possibly infinite, number of other universes. So our cosmos is just one tiny corner of a much larger multiverse.

    Susskind and Bousso have put forward the idea that the multiverse and the many worlds interpretation of quantum mechanics are formally equivalent, but if both quantum mechanics and the multiverse take special forms.

    Let’s take quantum mechanics first. Susskind and Bousso propose that it is possible to verify the predictions of quantum mechanics. In theory, it could be done if an observer could perform an infinite number of experiments and observe the outcome of them all, which is known as the supersymmetric multiverse with vanishing cosmological constant.

    If the universe takes this form, then it is possible to carry out an infinite number of experiments within the causal horizon of each other. At each instant in time, an infinite (or very large) number of experiments take place within the causal horizon of each other. As observers, we are capable of seeing the outcome of any of these experiments but we actually follow only one.

    Bousso and Susskind argue that since the many worlds interpretation is possible only in their supersymmetric multiverse, they must be equivalent. “We argue that the global multiverse is a representation of the many-worlds in a single geometry,” they say, calling this new idea the multiverse interpretation of quantum mechanics.

    But we have now entered the realm of what mathematical physicist Peter Woit of Columbia calls “Not Even Wrong, because the theory lacks is a testable prediction that would help physicists distinguish it experimentally from other theories of the universe. And without this crucial element, the multiverse interpretation of quantum mechanics is little more than philosophy, according to Woit.

    What this new supersymmetric multiverse interpretation does have is a simplicity– it’s neat and elegant that the many worlds and the multiverse are equivalent. Ockham’s Razor is fulfilled and no doubt, many quantum physicists delight in what appears to be an exciting. plausible interpretation of ultimate if currently untestable, reality.

    Ref: arxiv.org/abs/1105.3796: The Multiverse Interpretation of Quantum Mechanics

    The Daily Galaxy via technologyreview.com

    Image credit: hellstormde.deviantart.com

    See the full article here.

    Please help promote STEM in your local schools

    stem

    STEM Education Coalition

     
  • richardmitnick 1:48 pm on March 1, 2015 Permalink | Reply
    Tags: , Basic Research, ,   

    From Perimeter: “Pioneering Women of Physics” 

    Perimeter Institute
    Perimeter Institute

    February 25, 2015

    For more information, contact:
    Lisa Lambert
    Manager, External Relations and Public Affairs
    llambert@perimeterinstitute.ca
    (519) 569-7600 x5051

    They discovered pulsars, found the first evidence of dark matter, pioneered mathematics, radioactivity, nuclear fission, elasticity, and computer programming, and have even stopped light.
    Perimeter celebrates women who made pioneering contributions to physics, often overcoming tremendous challenges to do so.

    1

    2

    3

    4

    5

    6

    7

    8

    9

    10

    12

    13

    14

    15

    16

    17

    18

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    About Perimeter

    Perimeter Institute is a leading centre for scientific research, training and educational outreach in foundational theoretical physics. Founded in 1999 in Waterloo, Ontario, Canada, its mission is to advance our understanding of the universe at the most fundamental level, stimulating the breakthroughs that could transform our future. Perimeter also trains the next generation of physicists through innovative programs, and shares the excitement and wonder of science with students, teachers and the general public.

     
  • richardmitnick 9:29 am on March 1, 2015 Permalink | Reply
    Tags: , Basic Research, Sky and Telescope, U Toronto Dragonfly Telescope Array   

    From S&S: “Dark Galaxies Discovered in Coma Cluster” 

    Sky and Telescope

    Sky and Telescope News

    November 19, 2014
    Monica Young

    1
    Coma Cluster
    Adam Block / Mount Lemmon SkyCenter / University of Arizona

    The Coma Cluster, visible in the evening skies of spring and summer, reveals its jewel box to large backyard telescopes: several thousand galaxies sardine-packed into a space only 20 million light-years across.

    But there’s more to the Coma Cluster than meets the eye — or the backyard telescope.

    Pieter van Dokkum (Yale University) and colleagues took a unique look at Coma through the Dragonfly Telephoto Array, eight Canon telephoto lenses coupled to CCD cameras. The Dragonfly is designed to find faint, fuzzy blobs, but what its images revealed surprised the team.

    U Toronto Dunlap Dragonfly telescope Array
    The Dragonfly Telephoto Array currently consists of ten Canon telephoto lenses coupled to CCD cameras. (The paper used eight lens/CCD pairings.) The array is designed to image low surface brightness objects. Dunlap Institute for Astronomy & Astrophysics / University of Toronto

    On Coma’s outskirts lurk 47 galaxies similar in size to the Milky Way — but with 1,000 times fewer stars. To survive in crowded Coma, these dark galaxies must contain 98% dark matter to hold themselves together, much higher than the fraction in the universe at large (83%).

    3
    Hubble imaging picked up one of the dark galaxies serendipitously. The galaxy’s smattering of red stars is barely visible against the backdrop.
    Pieter van Dokkum & others

    NASA Hubble Telescope
    Hubble

    The galaxies’ size depends on their distance, so to make sure this result wasn’t just a trick of perspective, van Dokkum and colleagues had to make sure these galaxies really belonged to the Coma cluster, more than 300 million light-years away. If they turned out to live nearby, the galaxies’ size would be akin to regular ol’ dwarf galaxies.

    Determining cluster membership was a challenge because the objects are far too faint to study in the usual ways, such as taking a spectrum to determine their distance. Nonetheless, “van Dokkum and his co-authors make quite a convincing case,” says Mark den Brok (University of Utah).

    The authors initially expected the galaxies to be distributed randomly, as they would be if they lay in the foreground near the Milky Way. Instead, the galaxies cluster around the center of the image in the cluster’s periphery. The discovery of a serendipitous Hubble image of one of the galaxies strengthened the team’s case, den Brok says, definitively showing that it doesn’t have the traits of a nearby dwarf galaxy.

    Starless Galaxies

    Somehow these weirdly faint galaxies have lost their stars — or they never had many stars in the first place. Van Dokkum and colleagues suggest that these may be “failed” galaxies, having forfeited most of their star-building gas after hosting a first generation of stars.

    Simulations that track the evolution of large-scale structure suggest that even normal galaxies start out with three times more star-building material than they develop into stars. So whatever process works to limit star formation in normal galaxies is working particularly well in these dark matter-rich galaxies.

    “Our simulations have shown that one way to limit star formation so drastically is to use the energy stars produce when they blow up as supernovae,” says Greg Stinson (Max Planck Institute for Astronomy, Germany). “It turns out that this disruption leads directly to galaxies that look like the ones van Dokkum is seeing.”

    “I was actually very much relieved to see Prof. van Dokkum’s paper,” Stinson adds. Dark matter simulations have been producing galaxies with exactly the size and matter distribution that van Dokkum’s team observed, but such galaxies are naturally difficult to observe.

    It’s ironic that dark matter-rich galaxies were discovered in Coma, the birthplace of dark matter theory. Observations of the same cluster in 1933 helped Fritz Zwicky (Caltech) first conceive of the invisible matter that shapes the large-scale structure of the universe. Now ever-deeper observations continue to help astronomers understand dark matter’s role in galaxy evolution.

    See the full article here.

    Another view of the Coma Cluster

    2
    A Sloan Digital Sky Survey/Spitzer Space Telescope mosaic of the Coma Cluster in long-wavelength infrared (red), short-wavelength infrared (green), and visible light. The many faint green smudges are dwarf galaxies in the cluster.
    Credit: NASA/JPL-Caltech/GSFC/SDSS

    SDSS Telescope
    SDSS telescope

    NASA Spitzer Telescope
    Spitzer

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    About Sky & Telescope

    Sky & Telescope magazine, founded in 1941 by Charles A. Federer Jr. and Helen Spence Federer, has the largest, most experienced staff of any astronomy magazine in the world. Its editors are virtually all amateur or professional astronomers, and every one has built a telescope, written a book, done original research, developed a new product, or otherwise distinguished him or herself.

    A Brief History of Sky & Telescope

    Sky & Telescope magazine, now in its eighth decade, came about because of some happy accidents. Its earliest known ancestor was a four-page bulletin called The Amateur Astronomer, which was begun in 1929 by the Amateur Astronomers Association in New York City. Then, in 1935, the American Museum of Natural History opened its Hayden Planetarium and began to issue a monthly bulletin that became a full-size magazine called The Sky within a year. Under the editorship of Hans Christian Adamson, The Sky featured large illustrations and articles from astronomers all over the globe. It immediately absorbed The Amateur Astronomer.

    The Telescope

    Meanwhile, The Telescope first appeared as a quarterly magazine in March 1931 under the editorship of Harlan Stetson, director of the Perkins Observatory in Ohio. It featured popular articles about contemporary research written by professional astronomers. In 1934 Stetson moved to Cambridge, Massachusetts, and brought the magazine with him. Publishing duties were assumed by the Harvard College Observatory (HCO), and The Telescope became bimonthly.

    A New Beginning

    The first issue of the merged Sky & Telescope came out in November 1941, just one month before the bombing of Pearl Harbor.

     
  • richardmitnick 8:39 am on March 1, 2015 Permalink | Reply
    Tags: , Basic Research,   

    From Cornell: “The Irving Porter Church Telescope” 

    Cornell Bloc

    Cornell University

    2015-02-27
    Michael Roman

    1

    Fuertes Observatory was completed in 1917 with a dome capable of housing a 12-inch (0.3 m) equatorial refracting telescope; however, at the time, the University had yet to acquire such a telescope. Several small “transit” telescopes used for instruction in civil engineering and geodesy were installed on piers in the eastern wing of the observatory, while a 4 1/2″ (0.11 m) equatorial telescope owned by the College of Civil Engineering was temporarily installed in place of the anticipated 12″.

    Cornell Fuertes Observatory
    Fuertes Observatory

    By 1919, A pair of 12″ surplus flint and crown glass blanks was acquired from Yerkes Observatory of the University of Chicago by Irving Porter Church (’73), the retired chair of the Department of Civil Engineering at Cornell. These were delivered to the Pittsburgh firm, the John A. Brashear Co., where they were polished and figured, and delivered to Cornell in 1920, the year of Brashear’s death.

    The renowned Warner and Swasey company was contracted early in 1922 to build a mounting, which was completed and installed at Cornell in October of that year. Much of the necessary funds for the mounting were obtained through donations from alumni. The dedication, held on 15 June 1923, named the telescope for Professor Church, who was then still alive.

    The telescope optics consist of a 12″ (0.3m) pair of objective lenses, ground of crown and flint glass, that form an achromatic lens with a focal length of 180″ (4.6m) and a focal ratio of f/15. Brashear-made optics commonly place the flint element of glass “forward” towards the sky, unlike most refractor designs. Such is the case for the Irving Porter Church refractor; the forward element is a negative meniscus lens made of flint glass, while the rear element is a positive biconvex lens made of crown glass. The achromat doublet was designed for “visual” correction of colors, with the shapes of the two objective lenses calculated to produce the least amount of color fringing in the wavelengths where the eye is most sensitive — that is, the green to yellow region. As a result, bright stars exhibit a blue-violet halo from poor focus outside the eye’s most sensitive region.

    The telescope includes an auxiliary color correction lens, midway in the telescope tube, which can be inserted into the beam to change the correction of colors to produce best focus in the violet to blue section of the spectrum: this was intended to make the telescope function well with photographic plates available at the time of its construction, whose chief sensitivity was in this color range.

    Professor Church died in 1931. In 1964, monies were obtained to endow an Irving Porter Church professorship in engineering — this prestigious post is currently held by Joseph A. Burns, professor of engineering and astronomy.

    The Irving Porter Church telescope is open to the public on most Friday nights throughout the year, courtesy of the Cornell Astronomical Society.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition
    Once called “the first American university” by educational historian Frederick Rudolph, Cornell University represents a distinctive mix of eminent scholarship and democratic ideals. Adding practical subjects to the classics and admitting qualified students regardless of nationality, race, social circumstance, gender, or religion was quite a departure when Cornell was founded in 1865.

    Today’s Cornell reflects this heritage of egalitarian excellence. It is home to the nation’s first colleges devoted to hotel administration, industrial and labor relations, and veterinary medicine. Both a private university and the land-grant institution of New York State, Cornell University is the most educationally diverse member of the Ivy League.

    On the Ithaca campus alone nearly 20,000 students representing every state and 120 countries choose from among 4,000 courses in 11 undergraduate, graduate, and professional schools. Many undergraduates participate in a wide range of interdisciplinary programs, play meaningful roles in original research, and study in Cornell programs in Washington, New York City, and the world over.

     
  • richardmitnick 7:06 am on February 28, 2015 Permalink | Reply
    Tags: Basic Research, ESA Lisa Pathfinder,   

    From BBC: “Lisa Pathfinder: ‘Exquisite’ gravity probe leaves UK” 

    BBC
    BBC

    28 February 2015
    Jonathan Amos

    1
    The Lisa Pathfinder modules: The science satellite sits atop its propulsion unit. The Lisa Pathfinder contract represented a watershed for UK industry in space.

    British industry has completed construction of the modules that make up the Lisa Pathfinder satellite.

    ESA LISA Pathfinder
    LISA Pathfinder

    This remarkable probe will test the key technologies needed to detect gravitational waves in space. If that can be done, it would open up black holes and other astrophysical phenomena to a completely new era of scientific investigation. Lisa Pathfinder’s modules were assembled at the UK arm of Airbus Defence and Space. They leave for Germany on Monday, to go to the IABG consultancy just outside Munich for some final integration and testing. From there, they will be shipped to Kourou in French Guiana for a rocket launch in September.

    The European Space Agency (ESA) mission is the first to be led industrially from the UK since the Giotto satellite was sent to fly past Comet Halley in 1986. As such, Lisa Pathfinder represents a watershed moment for the British space sector. “There were some lean years after Giotto, but you can see the momentum we now have. We’re at the start of something really special,” Andy Stroomer, from Airbus in Stevenage, told BBC News.

    5
    The aim is to put two gold-platinum blocks in free-fall and then track their relative movement using lasers

    Still being worked on in Pathfinder’s big cleanroom are ESA projects worth more than a billion euros in total. These are satellites to visit the Sun and observe the Earth. And just a stone’s throw away is a brand new facility under construction which will house the assembly of the robotic rover that Europe plans to send to the surface of Mars in 2019. The two parts of Lisa Pathfinder heading out of Stevenage comprise the main satellite and the propulsion unit that will push it away from Earth to begin its mission. At the moment, the spacecraft’s all-important science instrument package is absent. This will be installed in the coming weeks at IABG. Lisa Pathfinder is a demonstrator for a future satellite idea that Europe hopes to launch in the 2030s. This is a concept known as the Laser Interferometric Space Antenna (LISA), which will endeavour to detect gravitational waves.

    3

    [Albert] Einstein’s theory of general relativity predicts that these ripples in the fabric of space-time should be generated when massive objects like black holes coalesce and merge. And although the signal is expected to be extremely faint, it should still be apparent to an ultra-stable, super-fine measurement system. The Pathfinder’s job is to prove the metrology. To do this, it will try to put two small gold-platinum blocks into a perfect free-fall and then track their relative movement using lasers. The intention is to get these blocks following a line that is defined only by gravity. To do that requires that all other forces that might interfere with the demonstration are removed. This means, for example, carefully controlling the influence of temperatures and magnetic fields. Even the vacuum state will introduce “noise” into the system if some residual gas molecules are allowed to collide with the blocks. The experiment has been designed such that disturbances to the blocks as small as just a few picometers should be noticed. One picometer is a small fraction of the width of a hydrogen atom.

    4
    Coalescing massive bodies should radiate gravitational waves at the speed of light

    Cesar Garcia is the European Space Agency’s project manager on Lisa Pathfinder. He describes the satellite as perhaps the most exquisite ever built. He said: “The final objective is to be convinced that we can achieve and then measure a pure geodesic motion. That is, a motion subject only to the Riemann tensor – to the curvature of space-time. This is what we aim to do – to work on the noise sources, to suppress the noise sources, to learn the noise sources; and then what remains must be a straight line.”

    It is in these conditions of perfect free-fall that one would look for gravitational waves. Lisa Pathfinder itself cannot sense them, however. The ripples produced by merging black holes are at too low a frequency.

    But if the methodology is scaled up as proposed for the Lisa mission proper, with precision measurement of blocks separated by millions of km, the very delicate signal ought then to show itself.
    David Southwood was the director of science at Esa in 2004 when the agency contracted Airbus to build Lisa Pathfinder. Now on the steering board of the UK Space Agency, he was present on Friday to see the spacecraft modules packed up ready for the transfer to IABG. He told BBC News: “It’s a fascinating mission right at the frontier of understanding and it could lead one day to the detection of gravitational waves in space. But these technologies don’t need to be used just to measure gravity. It’s in the nature of things that once you’ve pushed something to the extreme for a particular purpose, another smart person is inspired to take those ideas and put them to use in another application. What that is, no-one can predict. That’s the beauty of it.”

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
  • richardmitnick 5:52 am on February 28, 2015 Permalink | Reply
    Tags: Basic Research, , exolife   

    From Cornell: “Life ‘not as we know it’ possible on Saturn’s moon Titan” 

    Cornell Bloc

    Cornell University

    Feb. 27, 2015
    Anne Ju

    1
    Graduate student James Stevenson, astronomer Jonathan Lunine and chemical engineer Paulette Clancy, with a Cassini image of Titan in the foreground of Saturn, and an azotosome, the theorized cell membrane on Titan. Jason Koski/University Photography

    Liquid water is a requirement for life on Earth. But in other, much colder worlds, life might exist beyond the bounds of water-based chemistry.

    Taking a simultaneously imaginative and rigidly scientific view, Cornell chemical engineers and astronomers offer a template for life that could thrive in a harsh, cold world – specifically Titan, the giant moon of Saturn. A planetary body awash with seas not of water, but of liquid methane, Titan could harbor methane-based, oxygen-free cells that metabolize, reproduce and do everything life on Earth does.

    Their theorized cell membrane, composed of small organic nitrogen compounds and capable of functioning in liquid methane temperatures of 292 degrees below zero, is published in Science Advances, Feb. 27. The work is led by chemical molecular dynamics expert Paulette Clancy, the Samuel W. and Diane M. Bodman Professor of Chemical and Biomolecular Engineering, with first author James Stevenson, a graduate student in chemical engineering. The paper’s co-author is Jonathan Lunine, the David C. Duncan Professor in the Physical Sciences in the College of Arts and Sciences’ Department of Astronomy.

    Lunine is an expert on Saturn’s moons and an interdisciplinary scientist on the Cassini-Huygens mission that discovered methane-ethane seas on Titan.

    NASA Cassini Spacecraft
    Cassini

    Intrigued by the possibilities of methane-based life on Titan, and armed with a grant from the Templeton Foundation to study non-aqueous life, Lunine sought assistance about a year ago from Cornell faculty with expertise in chemical modeling. Clancy, who had never met Lunine, offered to help.

    “We’re not biologists, and we’re not astronomers, but we had the right tools,” Clancy said. “Perhaps it helped, because we didn’t come in with any preconceptions about what should be in a membrane and what shouldn’t. We just worked with the compounds that we knew were there and asked, ‘If this was your palette, what can you make out of that?’”

    On Earth, life is based on the phospholipid bilayer membrane, the strong, permeable, water-based vesicle that houses the organic matter of every cell. A vesicle made from such a membrane is called a liposome. Thus, many astronomers seek extraterrestrial life in what’s called the circumstellar habitable zone, the narrow band around the sun in which liquid water can exist. But what if cells weren’t based on water, but on methane, which has a much lower freezing point?

    2
    A representation of a 9-nanometer azotosome, about the size of a virus, with a piece of the membrane cut away to show the hollow interior. James Stevenson

    The engineers named their theorized cell membrane an “azotosome,” “azote” being the French word for nitrogen. “Liposome” comes from the Greek “lipos” and “soma” to mean “lipid body;” by analogy, “azotosome” means “nitrogen body.”

    The azotosome is made from nitrogen, carbon and hydrogen molecules known to exist in the cryogenic seas of Titan, but shows the same stability and flexibility that Earth’s analogous liposome does. This came as a surprise to chemists like Clancy and Stevenson, who had never thought about the mechanics of cell stability before; they usually study semiconductors, not cells.

    The engineers employed a molecular dynamics method that screened for candidate compounds from methane for self-assembly into membrane-like structures. The most promising compound they found is an acrylonitrile azotosome, which showed good stability, a strong barrier to decomposition, and a flexibility similar to that of phospholipid membranes on Earth. Acrylonitrile – a colorless, poisonous, liquid organic compound used in the manufacture of acrylic fibers, resins and thermoplastics – is present in Titan’s atmosphere.

    Excited by the initial proof of concept, Clancy said the next step is to try and demonstrate how these cells would behave in the methane environment – what might be the analogue to reproduction and metabolism in oxygen-free, methane-based cells.

    Lunine looks forward to the long-term prospect of testing these ideas on Titan itself, as he put it, by “someday sending a probe to float on the seas of this amazing moon and directly sampling the organics.”

    Stevenson said he was in part inspired by science fiction writer Isaac Asimov, who wrote about the concept of non-water-based life in a 1962 essay, “Not as We Know It.”

    Said Stevenson: “Ours is the first concrete blueprint of life not as we know it.”

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition
    Once called “the first American university” by educational historian Frederick Rudolph, Cornell University represents a distinctive mix of eminent scholarship and democratic ideals. Adding practical subjects to the classics and admitting qualified students regardless of nationality, race, social circumstance, gender, or religion was quite a departure when Cornell was founded in 1865.

    Today’s Cornell reflects this heritage of egalitarian excellence. It is home to the nation’s first colleges devoted to hotel administration, industrial and labor relations, and veterinary medicine. Both a private university and the land-grant institution of New York State, Cornell University is the most educationally diverse member of the Ivy League.

    On the Ithaca campus alone nearly 20,000 students representing every state and 120 countries choose from among 4,000 courses in 11 undergraduate, graduate, and professional schools. Many undergraduates participate in a wide range of interdisciplinary programs, play meaningful roles in original research, and study in Cornell programs in Washington, New York City, and the world over.

     
c
Compose new post
j
Next post/Next comment
k
Previous post/Previous comment
r
Reply
e
Edit
o
Show/Hide comments
t
Go to top
l
Go to login
h
Show/Hide help
shift + esc
Cancel
Follow

Get every new post delivered to your Inbox.

Join 418 other followers

%d bloggers like this: