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    galaxy evolution tagged posts

    Observable Universe contains 2 trillion Galaxies, 10X more than previously thought

    October 15, 2016, Categories  Astronomy/Space

    This Hubble Space Telescope view reveals thousands of galaxies stretching back into time across billions of light-years of space. The image covers a portion of a large galaxy census called the Great Observatories Origins Deep Survey (GOODS). Besides the myriad of galaxies visible in this image, only 10 percent of the total number of galaxies in the universe are observable for the current generation of telescopes, according to a new analysis of the GOODS and other Hubble deep-field surveys. The study's researchers concluded that at least 10 times more galaxies exist in the observable universe than previously thought. The analysis places the universe's estimated population at, minimally, 2 trillion galaxies. According to the research, about 90 percent of galaxies in the observable universe are too faint and too far away to be seen with present-day telescopes. Credit: NASA, ESA, the GOODS Team, and M. Giavialisco (University of Massachusetts, Amherst)

    This Hubble Space Telescope view reveals thousands of galaxies stretching back into time across billions of light-years of space. The image covers a portion of a large galaxy census called the Great Observatories Origins Deep Survey (GOODS). Besides the myriad of galaxies visible in this image, only 10 percent of the total number of galaxies in the universe are observable for the current generation of telescopes, according to a new analysis of the GOODS and other Hubble deep-field surveys. The study’s researchers concluded that at least 10 times more galaxies exist in the observable universe than previously thought. The analysis places the universe’s estimated population at, minimally, 2 trillion galaxies...

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    It’s not easy being Green: What Colors tell us about Galaxy Evolution

    July 3, 2016, Categories  Astronomy/Space

    The green galaxy is caught in the act of transforming from blue to red as its gas supply runs out. Credit: James Trayford/EAGLE/Durham University

    The green galaxy is caught in the act of transforming from blue to red as its gas supply runs out. Credit: James Trayford/EAGLE/Durham University

    An international team used new computer modelling of the Universe to investigate the colours that galaxies have and what those colours might tell us about how galaxies evolve. Using the state-of-the-art EAGLE simulations, the researchers modelled how both the ages and composition of stars in galaxies translate into the colour of light that they produce. These simulations showed that colours of galaxies can also help diagnose how they evolve.

    While red and blue galaxies are relatively common, rare green galaxies are likely to be at an important stage in their evolution, when they are rapidly turning from blue – when new stars and planets are being...

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    A Superwind Blown from the Heart of a Galaxy Tells the Tale of a Merger

    February 4, 2016, Categories  Astronomy/Space

    Blue, green, and red colors are attributed to the B-band, R-band, and H-alpha (emission line from ionized hydrogen gas) images, respectively. The giant ionized gas blown out from the galaxy is seen in red. Credit: Hiroshima University / NAOJ

    Blue, green, and red colors are attributed to the B-band, R-band, and H-alpha (emission line from ionized hydrogen gas) images, respectively. The giant ionized gas blown out from the galaxy is seen in red. Credit: Hiroshima University / NAOJ

    Astronomers have revealed the detailed structure of a massive 300,000 light-yr long ionized gas outflow streaming from starburst galaxy NGC 6240. The light-collecting power and high spatial resolution of Subaru Telescope made it possible to study, for the first time, the complex structure of one of the largest known superwinds being driven by starbirth – and star death.

    The term “starburst” indicates large-scale intensive star-forming activity, making a “starburst galaxy” one where starbirth is occurring on a grand scale...

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