Hubble sees the graceful dance of 2 interacting galaxiesOctober 31, 2007A pair of galaxies, known collectively as Arp 87, is one of hundreds of interacting and merging galaxies known in our nearby Universe. Arp 87 was originally discovered and catalogued by astronomer Halton Arp in the 1970s. Arp's Atlas of Peculiar Galaxies is a compilation of astronomical photographs using the Palomar 200-inch Hale and the 48-inch Samuel Oschin telescopes. The resolution in the Hubble image shows exquisite detail and fine structure that was not observable when Arp 87 was first discovered in the 1970's. The two main players comprising Arp 87 are NGC 3808 on the right (the larger of the two galaxies) and its companion NGC 3808A on the left. NGC 3808 is a nearly face-on spiral galaxy with a bright ring of star formation and several prominent dust arms. Stars, gas, and dust flow from NGC 3808, forming an enveloping arm around its companion. NGC 3808A is a spiral galaxy seen edge-on and is surrounded by a rotating ring that contains stars and interstellar gas clouds. The ring is situated perpendicular to the plane of the host galaxy disk and is called a "polar ring." As seen in other mergers similar to Arp 87, the corkscrew shape of the tidal material or bridge of shared matter between the two galaxies suggests that some stars and gas drawn from the larger galaxy have been caught in the gravitational pull of the smaller one. The shapes of both galaxies have been distorted by their gravitational interaction with one another. Interacting galaxies often exhibit high rates of star formation. Many lines of evidence - colours of their starlight, intensity of emission lines from interstellar gas, far-infrared output from heated interstellar dust - support this fact. Some merging galaxies have the highest levels of star formation we can find anywhere in the nearby Universe. A major aspect of this excess star formation could be properly revealed only when Hubble turned its imaging capabilities toward colliding galaxies. Among the observatory's first discoveries was that galaxies with very active star formation contain large numbers of super star clusters - clusters more compact and richer in young stars than astronomers were accustomed to seeing in our galactic neighbourhood. Arp 87 is in the constellation Leo, the Lion, approximately 300 million light-years away from Earth. These observations were taken in February 2007 with the Wide Field Planetary Camera 2. Light from isolated blue, green, red, and infrared ranges was combined to form this colour image. ESA/Hubble Information Centre |
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| Related Star Formation Current Events and Star Formation News Articles Rapid star formation spotted in 'stellar nurseries' of infant galaxies The Universe's infant galaxies enjoyed rapid growth spurts forming stars like our sun at a rate of up to 50 stars a year, according to scientists at Durham University. 'Dropouts' pinpoint earliest galaxies Astronomers, conducting the broadest survey to date of galaxies from about 800 million years after the Big Bang, have found 22 early galaxies and confirmed the age of one by its characteristic hydrogen signature at 787 million years post Big Bang. VERITAS telescopes help solve 100-year-old mystery: The origin of cosmic rays Nearly 100 years ago, scientists detected the first signs of cosmic rays - subatomic particles (mostly protons) that zip through space at nearly the speed of light. Iowa State researchers contribute to discovery of gamma rays from starburst galaxy Iowa State University astrophysicists contributed to the recent discovery that a galaxy quickly creating new stars is also a source of high energy gamma rays. Starburst galaxy sheds light on longstanding cosmic mystery An international collaboration that includes scientists from the University of Delaware's Bartol Research Institute in the Department of Physics and Astronomy has discovered very-high-energy gamma rays in the Cigar Galaxy (M82), a bright galaxy filled with exploding stars 12 million light years from Earth. NASA's Fermi Telescope Detects Gamma-Ray From Nearby galaxies undergoing a furious pace of star formation also emit lots of gamma rays, say astronomers using NASA's Fermi Gamma-ray Space Telescope. The Milky Way's tiny but tough galactic neighbor In the new ESO image, Barnard's Galaxy glows beneath a sea of foreground stars in the direction of the constellation of Sagittarius (the Archer). Stripped down: Hubble highlights 2 galaxies that are losing it Ram pressure is the drag force that results when something moves through a fluid - much like the wind you feel in your face when bicycling, even on a still day - and occurs in this context as galaxies orbiting about the centre of the cluster move through the intra-cluster medium, which then sweeps out gas from within the galaxies. Swift Makes Best-ever Ultraviolet Portrait of Andromeda Galaxy In a break from its usual task of searching for distant cosmic explosions, NASA's Swift satellite has acquired the highest-resolution view of a neighboring spiral galaxy ever attained in the ultraviolet. Magnetic Fields Play Larger Role in Star Formation than Previously Thought he simple picture of star formation calls for giant clouds of gas and dust to collapse inward due to gravity, growing denser and hotter until igniting nuclear fusion. In reality, forces other than gravity also influence the birth of stars. New research shows that cosmic magnetic fields play a more important role in star formation than previously thought. More Star Formation Current Events and Star Formation News Articles |
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