Ramanisblog

Tag: astronomy

  • Known Universe-Journey to the Stars.-Video.

    http://www.stumbleupon.com/su/2TzVUC/www.youtube.com/watch%3Fv%3D17jymDn0W6U

  • Astronomers Reveal First Objects In Our Universe-Video.

    June 1, 2007 — Astronomers removed light from closer and better known galaxies and stars from pictures taken with the Spitzer Space Telescope. The remaining images are believed to be the first objects in space, 13 billion light years away.

    The first stars in our universe are long gone, but their light still shines, giving us a peek at what the universe looked like in its early years.
    Astrophysicists believe they’ve spotted a faint glow from stars born at the beginning of time. Harvey Moseley, Ph.D., an astrophysicist at the NASA Goddard Space Flight Center in Greenbelt, Maryland, says, “The reason they’re faint is just because they’re very, very far away, they’re over at the far edge of the universe.”
    After the big bang, the universe stayed dark for about 200 million years. Now, new pictures reveal the first light from objects 13 billion light years away, the infants of our universe. “So, we’re seeing what sometimes people call the first light in the universe, which formed after the big bang,” Dr. Moseley explains.
    Using pictures taken with the Spitzer Space Telescope, scientists first removed light from closer stars and galaxies. The light areas left in the background are believed to be the first objects in space. Alexander Kashlinsky, Ph.D., astrophysicist at the NASA Goddard Space Flight Center, says, “The early universe was a very hot place in this sense, like it was filled with objects that have been emitting light much more furiously than today.”
    Researchers say the objects are either stars, hundreds of times more massive than our own sun, or enormous black holes. Either way, the pictures bring us one step closer to learning how the universe was born. NASA’s planned James Webb Space Telescope will be able to identify the nature of the newfound clusters and determine if they are stars or black holes.
    BACKGROUND: Using a telescope as a time machine, scientists at NASA’s Goddard Space Flight Center are closer to identifying the first objects of the universe. The latest observations from the Spitzer Space Telescope suggest that infrared light detected in a prior study comes from clusters of bright objects that lived within the first billion years after the Big Bang.
    THE DARK AGE: According to current science, space, time and matter originated 13.7 billion years ago in a tremendous explosion called the Big Bang. A few hundred million years later, the first stars formed, ending the “dark age” of the universe. Astronomers believe the objects observed by the Spitzer telescope are either the first stars — hundreds of times more massive than our sun — or voracious black holes that are consuming gas and spilling out tons of energy. If they turn out to be stars, then the clusters might be the first mini-galaxies. Our own Milky Way was probably created when mini-galaxies like these merged.
    IN THE INFRARED: The Spitzer scientists were looking specifically at the cosmic infrared background of the universe, a diffuse light from the early epoch when structure first emerged in the cosmos. A prior study reported in 2005 detected infrared light, suggesting that it originated from clumps of the very first objects in the universe. This second analysis indicates that this patchy light is scattered across the entire sky and comes from clusters of bright, monstrous objects more than 13 billion light-years away. Although that light began its journey as ultraviolet or visible light, by the time it reached earth, its wavelengths had been stretched into the infrared by the growing space-time that causes the universe’s expansion. Based on the strength of the infrared light signal, they concluded that the total amount of energy produced by the objects was so large, only very large stars or black holes consuming a lot of matter would be capable of emitting it. Other parts of the cosmic infrared background are from distant starlight absorbed by dust and re-emitted as infrared light.
    SEEING IS BELIEVING: When we peer into space with a telescope, we are actually looking back in time. Telescopes detect emitted light, and the light that reaches us from the closest galaxy, Andromeda, for instance, has taken two million years to reach us. The Spitzer telescope looked at the first brilliant objects to exist in our universe. The Spitzer telescope scanned five areas of the sky for about 25 hours per region, collecting light even from the faintest of objects. Then astronomers meticulously subtracted light from things that were in the way, such as foreground galaxies and dust in our solar system, or in interstellar clouds. When all that was left was the most ancient light, the scientists studied fluctuations in the intensity of the infrared brightness, revealing a clustering of objects to produce the observed light pattern.
    The American Astronomical Society contributed to the information contained in the video portion of this report.
    http://www.sciencedaily.com/videos/2007/0607-first_stars_in_the_universe.htm

  • OH WHAT A COSMIC WEB WE WEAVE-Story and Video.

    Please read my blog on Time-a Non -Linear Theory filed under AstroPhysics for Indian philosophy’s great insight.
    Space fans are no doubt familiar with     the classic short educational film, “Powers of 10,” that provides an eye-popping tour of our universe from the very big to the very small — and ends up right back on the picnic blanket in the park from whence we started. But the original is pretty dated now that we’re wrapping up the “Oughts,” and I’m not just talking about the hairstyles and 1970s togs. We know so much more about our universe since this film was made.

    In fact, it’s really just in the last decade that our technology for exploring the cosmos has improved to the point where astronomers could see that vast galaxies actually clump together and form larger structures. Our universe is a vast tangled web of interconnected galaxy clusters linked by wispy filaments surrounding areas that can only be described as voids. And that’s what scientists have taken to calling it: the Cosmic Web.

    It’s incredibly difficult to model this vast web of galaxies, however, since all the components that make it up vary greatly by orders of magnitude. “Powers of 10” made good use of zooming out and zooming in for its limited cinematic purposes, but when it comes to computer simulations, that approach doesn’t work so well. KFC of the arXiv blog explains:

    “As the small scale structures become too small to resolve, most computer models apply some sort of statistical smoothing process to make the large scale calculations easier. But if you zoom back in again, there is no way to retrieve the information that is lost by the smoothing process other than to rebuild the picture again from the original data. …

    “[I]t’s a problem if you want to simulate how the large scale structures form from smaller structures and how, in turn, the shape of the large structures influences the way smaller structures evolve. This kind of feedback process is impossible to model when the smoothing process between different scales essentially destroys any meaningful links between them.”
    A pair of scientists at the University of Gronengen in the Netherlands think they might have the answer: the Delauney Tessellation Field Estimator. “Delauney tesselation” sounds like something vaguely unpleasant from Madeleine L’Engle’s A Wrinkle in Time, but it’s actually an approach to computer simulation in which galaxies are treated as points in 3D space. The space between them is filled in with tetrahedra governed by very strict rules about how they combine as scales get larger.

    What makes the technique developed by Rien can de Weygaert and Willem Schaap so intriguing to astronomers is that its rules or reversible. That means you can zoom out and zoom back in your simulation, and the critical information in the original structure is recreated instead of lost. And that means we could soon have an even better model of our great Cosmic Web — and maybe even an updated version of “Powers of Ten.”
    http://news.discovery.com/space/oh-what-a-cosmic-web-we-weave.html

  • Herschel space telescope captures birth of stars

    Very interesting.Please follow the link.Can you see a face in the second photograph?
    The European Space Agency (Esa) has released stunning new pictures from the recently launched Herschel telescope.
    The pictures show star formation, and have been described as among the most important images obtained from space for decades.
    Astronomers hope that, by analysing these images, they will be able to answer questions about how stars and galaxies are made.
    Herschel is the largest astronomical telescope ever to be put into space.
    It has captured images of previously invisible stardust. This is the stuff that galaxies, stars, planets and all life is made from, and scientists are studying it to follow the life cycle of the cosmos.

    The vacuum of space is full of wispy clouds of stardust

    Bruce Swinyard, from the UK’s Rutherford Appleton Laboratory in Oxfordshire, is a member of the research team that designed Herschel’s Spectral and Photometric Imaging Receiver (Spire), one of the three scientific instruments that is providing the telescope’s eyes.
    These three detectors allow Herschel to see far-infrared and sub-millimetre (radio) wavelengths of light, allowing it to peer through clouds of dust and gas and to see stars as they are born.
    This infrared capability also enables Herschel to look deep into space, to look at galaxies that thrived when the Universe was roughly a half to a fifth of its present age. This is a period in cosmic history when it is thought star formation was at its most prolific.
    Professor Swinyard explained that by looking at “young galaxies”, Herschel is able reveal some of the history of star formation.

    Herschel can see through clouds of gas released by dying stars
    He said that the thousands of galaxies the telescope had detected would allow researchers to test models of galaxy formation, and to uncover the chemical processes that make stardust.
    One of the pictures shows that the vacuum of space is actually full of star dust.
    Another shows the dust forming into clumps along magnetic lines – like pearls on a necklace. Each clump is a very early star – at its embryonic stage.
    Another picture shows a dying star. For this image Herschel was able to look beneath the clouds of gas that the star hurled out into space and reveal a donut ring of cosmic dust.
    This dust would have been blown outward until, hundreds of millions of years later, the dust clumped together again to form a brand new star.
    Astronomers will continue to study the images, which have already shown that the mechanisms of the cosmos may be more diverse and complex than current theory suggests.
    http://news.bbc.co.uk/2/hi/science/nature/8416263.stm