Baffling boxy bulgeNovember 18, 2009When targeting spiral galaxy bulges, astronomers often seek edge-on galaxies, as their bulges are more easily distinguishable from the disc. This exceptionally detailed edge-on view of NGC 4710 taken by the Advanced Camera for Surveys (ACS) aboard Hubble reveals the galaxy's bulge in the brightly coloured centre. The luminous, elongated white plane that runs through the bulge is the galaxy disc. The disc and bulge are surrounded by eerie-looking dust lanes. When staring directly at the centre of the galaxy, one can detect a faint, ethereal "X"-shaped structure. Such a feature, which astronomers call a "boxy" or "peanut-shaped" bulge, is due to the vertical motions of the stars in the galaxy's bar and is only evident when the galaxy is seen edge-on. This curiously shaped puff is often observed in spiral galaxies with small bulges and open arms, but is less common in spirals with arms tightly wrapped around a more prominent bulge, such as NGC 4710. NGC 4710 is a member of the giant Virgo Cluster of galaxies and lies in the northern constellation of Coma Berenices (the Hair of Queen Berenice). It is not one of the brightest members of the cluster, but can easily be seen as a dim elongated smudge on a dark night with a medium-sized amateur telescope. In the 1780s, William Herschel discovered the galaxy and noted it simply as a "faint nebula". It lies about 60 million light-years from the Earth and is an example of a lenticular or S0-type galaxy - a type that seems to have some characteristics of both spiral and elliptical galaxies. Astronomers are scrutinising these systems to determine how many globular clusters they host. Globular clusters are thought to represent an indication of the processes that can build bulges. Two quite different processes are believed to be at play regarding the formation of bulges in spiral galaxies: either they formed rather rapidly in the early Universe, before the spiral disc and arms formed; or they built up from material accumulating from the disc during a slow and long evolution. In this case of NGC 4710, researchers have spotted very few globular clusters associated with the bulge, indicating that its assembly mainly involved relatively slow processes. ESA/Hubble Information Centre |
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| Related Spiral Galaxy Current Events and Spiral Galaxy News Articles Where did today's spiral galaxies come from? Hubble shows that the beautiful spirals galaxies of the modern Universe were the ugly ducklings of six billion years ago. Watching a Cannibal Galaxy Dine A new technique using near-infrared images, obtained with ESO's 3.58-metre New Technology Telescope (NTT), allows astronomers to see through the opaque dust lanes of the giant cannibal galaxy Centaurus A, unveiling its "last meal" in unprecedented detail - a smaller spiral galaxy, currently twisted and warped. 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. NGC 4945: The Milky Way's not-so-distant Cousin ESO has released a striking new image of a nearby galaxy that many astronomers think closely resembles our own Milky Way. Herschel Space Telescope's SPIRE instrument package makes first-light observations A scientific instrument package developed in part by the University of Colorado at Boulder for the $2.2 billion orbiting Herschel Space Observatory that was launched in May by the European Space Agency has made its first successful observations, targeting two star-forming galaxies near the Milky Way. Exceptionally deep view of strange galaxy A spectacular new image of an unusual spiral galaxy in the Coma Galaxy Cluster has been created from data taken by the Advanced Camera for Surveys on the NASA/ESA Hubble Space Telescope. Stars stop forming when big galaxies collide Astronomers studying new images of a nearby galaxy cluster have found evidence that high-speed collisions between large elliptical galaxies may prevent new stars from forming, according to a paper to be published in a November 2008 issue of The Astrophysical Journal Letters. The Wild, Hidden Cousin of SN 1987A Over a decade after it exploded, one of the nearest supernovae in the last 25 years has been identified. This result was made possible by combining data from the vast online archives from many of the world's premier telescopes. Powerful Nearby Supernova Caught By Web One of the nearest supernovas in the last 25 years has been identified over a decade after it exploded. This result was made possible by combining data from the vast online archives from many of the world's premier telescopes. More Spiral Galaxy Current Events and Spiral Galaxy News Articles |
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