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  • richardmitnick 3:20 pm on June 3, 2016 Permalink | Reply
    Tags: , , , Einstein ring, Universe Today   

    From Dark Energy Survey via Universe Today: “New ‘Einstein Ring’ Discovered By Dark Energy Camera” 

    Dark Energy Icon
    The Dark Energy Survey

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    2 Jun , 2016
    Evan Gough, Universe Today

    A rare object called an Einstein Ring has been discovered by a team in the Stellar Populations group at the Instituto de Astrofísica de Canarias (IAC) in Spain. An Einstein Ring is a specific type of gravitational lensing.

    IAC

    Einstein’s Theory of General Relativity predicted the phenomena of gravitational lensing. Gravitational lensing tells us that instead of travelling in a straight line, light from a source can be bent by a massive object, like a black hole or a galaxy, which itself bends space time.

    Einstein’s General Relativity was published in 1915, but a few years before that, in 1912, Einstein predicted the bending of light. Russian physicist Orest Chwolson was the first to mention the ring effect in scientific literature in 1924, which is why the rings are also called Einstein-Chwolson rings.

    Gravitational lensing is fairly well-known, and many gravitational lenses have been observed. Einstein rings are rarer, because the observer, source, and lens all have to be aligned. Einstein himself thought that one would never be observed at all. “Of course, there is no hope of observing this phenomenon directly,” Einstein wrote in 1936.

    The team behind the recent discovery was led by PhD student Margherita Bettinelli at the University of La Laguna, and Antonio Aparicio and Sebastian Hidalgo of the Stellar Populations group at the Instituto de Astrofísica de Canarias (IAC) in Spain. Because of the rarity of these objects, and the strong scientific interest in them, this one was given a name: The Canarias Einstein Ring.

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    The “Canarias Einstein Ring.” The green-blue ring is the source galaxy, the red one in the middle is the lens galaxy. The lens galaxy has such strong gravity, that it distorts the light from the source galaxy into a ring. Because the two galaxies are aligned, the source galaxy appears almost circular. Image: This composite image is made up from several images taken with the DECam camera on the Blanco 4m telescope at the Cerro Tololo Observatory in Chile.

    There are three components to an Einstein Ring. The first is the observer, which in this case means telescopes here on Earth. The second is the lens galaxy, a massive galaxy with enormous gravity. This gravity warps space-time so that not only are objects drawn to it, but light itself is forced to travel along a curved path. The lens lies between Earth and the third component, the source galaxy. The light from the source galaxy is bent into a ring form by the power of the lens galaxy.

    When all three components are aligned precisely, which is very rare, the light from the source galaxy is formed into a circle with the lens galaxy right in the centre. The circle won’t be perfect; it will have irregularities that reflect irregularities in the gravitational force of the lens galaxy.

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    Another Einstein Ring. This one is named LRG 3-757. This one was discovered by the Sloan Digital Sky Survey, but this image was captured by Hubble’s Wide Field Camera 3. Image: NASA/Hubble/ESA

    The objects are more than just pretty artifacts of nature. They can tell scientists things about the nature of the lens galaxy. Antonio Aparicio, one of the IAC astrophysicists involved in the research said, “Studying these phenomena gives us especially relevant information about the composition of the source galaxy, and also about the structure of the gravitational field and of the dark matter in the lens galaxy.”

    Looking at these objects is like looking back in time, too. The source galaxy is 10 billion light years from Earth. Expansion of the Universe means that the light has taken 8.5 billion light years to reach us. That’s why the ring is blue; that long ago, the source galaxy was young, full of hot blue stars.

    The lens itself is much closer to us, but still very distant. It’s 6 billion light years away. Star formation in that galaxy likely came to a halt, and its stellar population is now old.

    The discovery of the Canarias Einstein Ring was a happy accident. Bettinelli was pouring over data from what’s known as the Dark Energy Camera (DECam) of the 4m Blanco Telescope at the Cerro Tololo Observatory, in Chile. She was studying the stellar population of the Sculptor dwarf galaxy for her PhD when the Einstein Ring caught her attention. Other members of the Stellar Population Group then used OSIRIS spectrograph on the Gran Telescopio CANARIAS (GTC) to observe and analyze it further.

    Gran Telescopio de Canarias exterior

    See the full article here .

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    DECam, built at FNAL
    NOAO/CTIO Victor M Blanco 4m Telescope which houses the DECam at Cerro Tololo, Chile
    DECam, built at FNAL; NOAO/CTIO Victor M Blanco 4m Telescope which houses the DECam at Cerro Tololo, Chile

    The Dark Energy Survey (DES) is designed to probe the origin of the accelerating universe and help uncover the nature of dark energy by measuring the 14-billion-year history of cosmic expansion with high precision. More than 120 scientists from 23 institutions in the United States, Spain, the United Kingdom, Brazil, and Germany are working on the project. This collaboration [has built] an extremely sensitive 570-Megapixel digital camera, DECam, and [has mounted] it on the Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory high in the Chilean Andes. Started in Sept. 2012 and continuing for five years, DES will survey a large swath of the southern sky out to vast distances in order to provide new clues to this most fundamental of questions.

     
  • richardmitnick 1:11 pm on March 24, 2013 Permalink | Reply
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    From Universe Today: “Sequester Cancels NASA Outreach” 

    UniverseToday

    “Well, it looks like it’s finally happened: the U.S. sequester – a “series of across-the-board cuts to government agencies totaling $1.2 trillion over 10 years” (CNN) — has finally hit NASA… right where it hurts, too: in public outreach and STEM programs.

    In an internal memo issued on the evening of Friday, March 22, the Administration notes that “effective immediately, all education and public outreach activities should be suspended, pending further review. In terms of scope, this includes all public engagement and outreach events, programs, activities, and products developed and implemented by Headquarters, Mission Directorates, and Centers across the Agency, including all education and public outreach efforts conducted by programs and projects.”

    Read more: http://www.universetoday.com/100949/sequester-cancels-nasa-outreach/#ixzz2OTseU9Jg

    NASA

     
  • richardmitnick 11:03 am on July 29, 2011 Permalink | Reply
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    From Universe Today: “Amber Waves Of Energy” 

    by Tammy Plotner on July 29, 2011

    “Have you ever seen the hot summer wind blow across a ripening field of wheat? If so, you’re familiar with the rippling effect. Now imagine that same crop – only the stalks are 32,000 feet high and on the surface of the Sun. This cascading effect is called Alfvén waves.

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    These jets, known as spicules, were captured in an SDO image on April 25, 2010. Combined with the energy from ripples in the magnetic field, they may contain enough energy to power the solar wind that streams from the sun toward Earth at 1.5 million miles per hour. Credit: NASA/SDO/AIA

    Thanks to NASA’s Solar Dynamics Observatory (SDO), we’re now able to see the effect of Alfvén waves, track their movements and see how much energy is being carried along. These new findings have enlighten[ed] solar researchers and may be the key to two other enigmatic solar occurrences – the intense heating of the corona to some 20 times hotter than the Sun’s surface and solar winds that blast up to 1.5 million miles per hour.

    ‘ SDO has amazing resolution so you can actually see individual waves,’ says Scott McIntosh at the National Center for Atmospheric Research in Boulder, Colo. ‘ Now we can see that instead of these waves having about 1000th the energy needed as we previously thought, it has the equivalent of about 1100W light bulb for every 11 square feet of the Sun’s surface, which is enough to heat the Sun’s atmosphere and drive the solar wind.’ ”

    There is a lot more. See the full article here.

    Find out about this really cool and beautiful graphic:

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    Credit: NASA/SDO/AIA

    Universe Today is another great WordPress blog.

     
  • richardmitnick 9:20 pm on July 14, 2011 Permalink | Reply
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    From Universe Today: “Are The Galaxies In Our Universe More Right-Handed Or Left-Handed?” 

    Tammy Plotner
    July 14, 2011

    “It’s called mirror symmetry and it has everything to do with a recent study done by physics professor Michael Longo and a team of five undergraduates from the University of Michigan. Their work encompasses the rotation direction of tens of thousands of spiral galaxies cataloged by the Sloan Digital Sky Survey. What they’re looking for is the shape of the Big Bang… and what they found is much more elaborate than they thought.

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    A new study found an excess of counter-clockwise rotating or “left-handed” spiral galaxies like this one, compared to their right-handed counterparts. This provides evidence that the universe does not have mirror symmetry. Credit: NASA, ESA

    ‘The mirror image of a counter-clockwise rotating galaxy would have clockwise rotation. More of one type than the other would be evidence for a breakdown of symmetry, or, in physics speak, a parity violation on cosmic scales.’ Longo said. However, there seems to be a certain “spin preference” when it comes to spiral galaxies toward the north pole of the Milky Way. Here they found an abundance of left-handed, or counter-clockwise rotating, spirals – an effect which extended beyond an additional 600 million light years.”

    More to read? You bet! See the full article here.

    Universe Today is another great WordPress blog.

     
  • richardmitnick 4:50 pm on July 13, 2011 Permalink | Reply
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    From Universe Today: “MAXI Peers Into Black Hole Binaries” 

    by Tammy Plotner on July 13, 2011

    “The Monitor of All-sky X-ray Image, or MAXI for short, spends its time aboard the ISS conducting a full sky survey every 92 minutes. Its sole purpose is to monitor X-ray source activity and report. Unlike stars seen in visible light, X-ray sources aren’t evenly distributed and can exhibit some highly unusual behavior. What causes these erratic moments? Read on…

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    X-ray all-sky image obtained by MAXI’s first 10-month observation Bright X-ray sources (mainly binaries comprising neutron stars and black holes) exist in large numbers around the Galactic Center (in the direction of Sagittarius) and along the Galactic Plane (Milky Way) and change from day to day. Colors indicate the “hardness” of X-ray spectrum. More than 200 X-ray sources including weak ones have been identified. Credit: JAXA

    ‘ Most visible stars shine with energies generated by nuclear fusion in their cores. In these stars, if the energy generated in their core increases more than usual, the whole object expands and eventually lowers the core temperature. In this way, negative feedback is activated to stabilize the nuclear reaction. For this reason, these stars shine very stably for most of their lifetime.’ says Nobuyuki Kawai of the Tokoyo Institute of Technology. ‘ On the other hand, the energy source of most intense X-ray sources is gravitational energy released when the gas surrounding extremely compact bodies like black holes and neutron stars is accreted onto them. The normal stars’ stabilizing mechanism does not work in this process, and accordingly, X-ray intensity fluctuates in response to changes in the supply of gas from the surrounding area.’

    See the full article here.

    Universe Today is another great WordPress blog.

     
  • richardmitnick 10:21 am on July 8, 2011 Permalink | Reply
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    From Universe Today: “Where Did Early Cosmic Dust Come From? New Research Says Supernovae” 

    by Nancy Atkinson on July 7, 2011

    “New observations from the infrared Herschel Space Observatory reveal that an exploding star expelled the equivalent of between 160,000 and 230,000 Earth masses of fresh dust. This enormous quantity suggests that exploding stars, called supernovae, are the answer to the long-standing puzzle of what supplied our early universe with dust.

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    This layout compares two pictures of a supernova remnant called SN 1987A — the left image was taken by the Herschel Space Observatory, and the right is an enlarged view of the circled region at left, taken with NASA’s Hubble Space Telescope. Image credit: ESA/NASA-JPL/UCL/STScI

    ‘ This discovery illustrates the power of tackling a problem in astronomy with different wavelengths of light, said Paul Goldsmith, the NASA Herschel project scientist at NASA’s Jet Propulsion Laboratory, Pasadena, Calif., who is not a part of the current study. ‘ Herschel’s eye for longer-wavelength infrared light has given us new tools for addressing a profound cosmic mystery.’ ”

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    This plot shows energy emitted from a supernova remnant called SN 1987A. Previously, NASA’s Spitzer Space Telescope detected warm dust around the object. Image credit: ESA/NASA-JPL/UCL/STScI

    There is much more to this story. See the full article here.

    Universe Today is another great WordPress blog.

     
  • richardmitnick 5:10 pm on July 4, 2011 Permalink | Reply
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    From Universe Today: “Dark Energy… And Zombie Stars!” 

    by Tammy Plotner on July 4, 2011

    “It’s called a Type Ia supernovae and it shines with the luminosity of a billion suns. For all intents and purposes, once they explode they’re dead… But it ain’t so. They might have a core of ash, but they come back to life by sucking matter from a companion star. Zombies? You bet. Zombie stars… And they can be used to measure dark energy.

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    Supernova 1994D. The supernova is the bright point in the lower-left. It is a type Ia thermonuclear supernova like those described by Howell. The supernova is on the edge of galaxy NGC 4526, depicted in the center of the image. Credit: NASA/Hubble Space Telescope

    Why are Type Ia supernovae findings important? Right now they’re instrumental in helping researchers like Andy Howell, adjunct professor of physics at UCSB and staff scientist at Las Cumbres Observatory Global Telescope Network (LCOGT), take a closer look at the mysteries of dark energy. ‘ We only discovered this about 20 years ago by using Type Ia supernovae, thermonuclear supernovae, as standard or calibrated candles,’ said Howell.”

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    D. Andrew Howell Credit: Katrina Marcinowski

    See the full post here. There is lots more.

    Universe Today is another great WordPress blog.

     
  • richardmitnick 7:17 pm on June 18, 2011 Permalink | Reply
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    From Universe Today: “Astronomy Without A Telescope – Star Seeds” 

    by Steve Nerlich on June 18, 2011

    “Molecular clouds are called so because they have sufficient density to support the formation of molecules, most commonly H2 molecules. Their density also makes them ideal sites for new star formation – and if star formation is prevalent in a molecular cloud, we tend to give it the less formal title of stellar nursery.

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    The Rho Ophiuchi cloud complex – within which the cloud L1688 is the most active star-forming location. Although hidden by dust, it is possible to study star formation by sub-millimetre astronomy. Credit NASA.

    See the full article here.
    Universe Today is another great WordPress blog.

     
  • richardmitnick 8:19 pm on June 16, 2011 Permalink | Reply
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    From Universe Today: “Black Hole Devours Star and Hurls Energy Across 3.8 Billion Light Years” 

    by Tammy Plotner on June 17, 2011

    Engaging the Hubble Space Telescope, Swift satellite and the Chandra X-ray Observatory, astronomers at the University of Warwick were quick to pick up a signal from Swift’s Burst Alert Telescope on March 28, 2011. In a classic line from Easy Rider, Jack Nicholson says: “It’s a UFO beaming back at you.” But this time it isn’t a UFO… it’s the death scream of a star being consumed by a black hole.

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    The alert was just the beginning of a series of x-ray blasts that turned out to be the largest and most luminous event so far recorded in a distant galaxy.”

    Read all about it here.

     
  • richardmitnick 12:17 pm on June 16, 2011 Permalink | Reply
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    From Universe Today: “New Clues To Solving Physics Riddle” 

    by Tammy Plotner on June 16, 2011

    “There are diminutive visitors to Earth. We’ve known about them and measured their presence since the 1960s. When the Sudbury Neutrino Observatory (SNO) turned on in May, 1999 the world became acutely aware of tiny particles known as solar neutrinos.

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    Credit: University of Tokyo

    The facility gathered data for seven years before shutting down. As we know, matter cannot be either created nor destroyed – so where did it originate? Exciting results produced by the international T2K neutrino experiment in Japan may be key to resolving this riddle.”

    See the full article here.

     
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