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    galaxy evolution tagged posts

    Face Recognition for Galaxies: Artificial Intelligence brings new tools to astronomy

    April 23, 2018, Categories  Astronomy/Space

    A 'deep learning' algorithm trained on images from cosmological simulations is surprisingly successful at classifying real galaxies in Hubble images. Top row: High-resolution images from a computer simulation of a young galaxy going through three phases of evolution (before, during, and after the "blue nugget" phase). Middle row: The same images from the computer simulation of a young galaxy in three phases of evolution as it would appear if observed by the Hubble Space Telescope. Bottom row: Hubble Space Telescope images of distant young galaxies classified by a deep learning algorithm trained to recognize the three phases of galaxy evolution. The width of each image is approximately 100,000 light years. Credit: Image credits for top two rows: Greg Snyder, Space Telescope Science Institute, and Marc Huertas-Company, Paris Observatory. For bottom row: The HST images are from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS).

    A ‘deep learning’ algorithm trained on images from cosmological simulations is surprisingly successful at classifying real galaxies in Hubble images. Top row: High-resolution images from a computer simulation of a young galaxy going through three phases of evolution (before, during, and after the “blue nugget” phase). Middle row: The same images from the computer simulation of a young galaxy in three phases of evolution as it would appear if observed by the Hubble Space Telescope. Bottom row: Hubble Space Telescope images of distant young galaxies classified by a deep learning algorithm trained to recognize the three phases of galaxy evolution. The width of each image is approximately 100,000 light years...

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    Massive Dead Disk Galaxy Challenges Theories of Galaxy Evolution

    June 22, 2017, Categories  Astronomy/Space

    This artist's concept shows what the young, dead, disk galaxy MACS2129-1, right, would look like when compared with the Milky Way galaxy, left. Although three times as massive as the Milky Way, it is only half the size. MACS2129-1 is also spinning more than twice as fast as the Milky Way. Note that regions of Milky Way are blue from bursts of star formation, while the young, dead galaxy is yellow, signifying an older star population and no new star birth. Credit: NASA, ESA, and Z. Levy (STScI)

    This artist’s concept shows what the young, dead, disk galaxy MACS2129-1, right, would look like when compared with the Milky Way galaxy, left. Although three times as massive as the Milky Way, it is only half the size. MACS2129-1 is also spinning more than twice as fast as the Milky Way. Note that regions of Milky Way are blue from bursts of star formation, while the young, dead galaxy is yellow, signifying an older star population and no new star birth. Credit: NASA, ESA, and Z. Levy (STScI)

    By combining the power of a “natural lens” in space with the capability of Hubble Space Telescope, astronomers made a surprising discovery – the first example of a compact yet massive, fast-spinning, disk-shaped galaxy that stopped making stars only a few billion years after the big bang...

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    Stars born in Winds from Supermassive Black holes

    March 29, 2017, Categories  Astronomy/Space

    Artist's impression of stars born in winds from supermassive black holes. Credit: ESO/M. Kornmesser

    Artist’s impression of stars born in winds from supermassive black holes. Credit: ESO/M. Kornmesser

    MUSE and X-shooter instruments on the Very Large Telescope (VLT) at ESO’s Paranal Observatory in Chile have been used to study an ongoing collision between two galaxies, known collectively as IRAS F23128-5919, 600 million light-years from Earth. The group observed the outflows – that originate near the supermassive black hole at the heart of the pair’s southern galaxy, and have found the first clear evidence that stars are being born within them. The discovery has many consequences for understanding galaxy properties and evolution.

    Such galactic outflows are driven by the huge energy output from the active and turbulent centres of galaxies...

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    Young, Thin and Hyperactive: That’s what Outlier Galaxies look like

    December 14, 2016, Categories  Astronomy/Space

    A new model explains the exceptiobns to the galaxy main model sequence

    A new model explains the exceptions to the galaxy main model sequence

    The more massive, or full of stars, a galaxy is, the faster the stars in it are formed. This seems to be the general rule, which is contradicted, however, by some abnormal cases, for example thin (not massive) galaxies that are hyperactive in their star formation. Until now the phenomenon had been explained by catastrophic external events like galaxies colliding and merging, but a new theory offers an alternative explanation, related to an in situ (internal) process of galaxy evolution. The new theory correctly reproduces the behaviour of both normal and abnormal (or outlier) galaxies, and may be further tested by new observations.

    If we put the galaxies for which we have the relevant data into a graph relating the mass ...

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