Latest Galaxy formation and evolution Stories
Lee Rannals for redOrbit.com - Your Universe Online The European Space Agency's (ESA) Herschel spacecraft has revealed that the supermassive black hole in the center of our galaxy is about to get a taste of some hot molecular gas. Sagittarius A has a mass of about four million times that of our Sun and sits about 26,000 light-years away from us. It is a few hundred times closer to us than any other galaxy with an active black hole at its center, making it ideal for studying these...
April Flowers for redOrbit.com - Your Universe Online A detailed study of an enormous cloud of hot gas that envelops two large, colliding galaxies has been made using NASA’s Chandra X-ray Observatory. This oversized gas reservoir contains as much mass as 10 billion Suns, is 300,000 light years across, and radiates more than 7 million degrees Kelvin. Scientists call this sort of cloud a “halo.” This particular halo is located in the system designated NGC 6240, which astronomers...
WATCH VIDEOS: [Animation of a Starburst Galaxy] | [Probing a Galactic Halo] Lee Rannals for redOrbit.com – Your Universe Online Astronomers writing in The Astrophysical Journal say they've observed how bursts of star formation have a major impact beyond the boundaries of their host galaxy. When galaxies form new stars, they can create frantic episodes of activity known as starbursts. Scientists using the Hubble Space Telescope say these events can affect galactic gas at distances...
University of Michigan The rare Green Pea galaxies discovered by the general public in 2007 could help confirm astronomers' understanding of reionization, a pivotal stage in the evolution of the early universe, say University of Michigan researchers. Reionization occurred a few hundred million years after the Big Bang as the first stars were turning on and forming the first galaxies. During this period, the space between the galaxies changed from an opaque, neutral fog to a transparent...
redOrbit Staff & Wire Reports - Your Universe Online Astronomers from the University of Colorado Boulder (CU-Boulder) believe that so-called sideline quasars located on the outer fringes of a larger, brighter active galactic nucleus might have joined forces with it to prevent the formation of small galaxies billions of years ago. Michael Shull, a professor of astrophysical and planetary sciences at the university’s Center for Astrophysics and Space Astronomy, and research...
April Flowers for redOrbit.com - Your Universe Online Astronomers using NASA's Hubble Space Telescope to peer deep into the vast stellar halo that envelopes our galaxy have uncovered tantalizing evidence for the possible existence of a shell of stars that are a relic of cannibalism by our Milky Way. For the first time ever, Hubble was used to gain precise measurements of the sideways motion of a small sample of stars located far from the galaxy's center. The unusual lateral motion of...
Watch the video "Magneto-Spin Alignment Effect Movie (Black Hole Jet)" April Flowers for redOrbit.com - Your Universe Online Black holes are voracious monsters at the center of galaxies that shape the growth and death of the stars around them with their tremendous gravitational pull and explosive ejections of energy. "Over its lifetime, a black hole can release more energy than all the stars in a galaxy combined," explains Roger Blandford, Stanford professor, director of the Kavli...
Lee Rannals for redOrbit.com - Your Universe Online A Rutgers University astronomer has created computer models and simulations that help to explain how galaxies formed and evolved. Astronomer Rachel Somerville, who works as a professor of astrophysics in the Department of Physics and Astronomy, School of Arts and Sciences, created these models to show how gases like hydrogen and helium coalesce into stars and galaxies and how exploding stars and black holes impact their galactic...
redOrbit Staff & Wire Reports - Your Universe Online Astronomers affiliated with the Harvard-Smithsonian Center for Astrophysics (CfA) have discovered a new structure in the Milky Way – a lengthy tendril comprised of dust and gas. The tendril – or “bone” as they refer to it – is long and slender, drawing comparisons to the fibula, or calf bone. In a statement, lead author Alyssa Goodman stated that this marks the first time that scientists have been able to locate such a...
April Flowers for redOrbit.com - Your Universe Online Astronomers have discovered a group of dwarf galaxies moving in unison near the Andromeda Galaxy around the host known as Messier 31 using the MegaCam on the Canada-France-Hawaii and W. M. Keck Observatory telescopes on the summit of Mauna Kea, Hawaii. Analogous to the planets of our own Solar System, the structure of these small galaxies – nearly half that orbit Andromeda - lies in a plane. What is truly surprising to the scientists,...
Latest Galaxy formation and evolution Reference Libraries
The Coma Cluster (Abell 1656), along with the Leo Cluster, is one of two major clusters compromising the Coma Supercluster. It contains over 1000 identified galaxies. Most of the galaxies in the center of the Coma Cluster are elliptical galaxies including both dwarf and giant. However the center is dominated by NGC 4874 and NGC 4889, two giant elliptical galaxies. The brightest galaxies are visible, a few degrees north of the galactic pole, with an amateur telescope larger than 20 cm. The...
The Abell 520 galaxy cluster is an strange structure formed by a major merger. Due to its odd and chaotic nature it has been given the nick-name the Train Wreck Cluster. The Dark Matter within the cluster does not act as expected like it does in other clusters, therefore, Abell 520 creates problems for many of the prevailing theories about Dark Matter. It also disrupts many alternative theories of modified gravity. Similar to the Bullet Cluster the gas contents and galaxies within the...
Ring Galaxy -- A subclass of interacting galaxies, ring galaxies, provides a unique laboratory for studying unusually large bursts of non-nuclear star formation. The rings in these systems are often large (10s of kiloparsecs) and contain what appear to be associations of giant H{\small II} regions. As a basis for future modeling of star forming regions in observed ring galaxies we present a series of combined n-body/gas numerical experiments on ring formation and evolution. Three...
Molecular Cloud -- Molecular clouds are interstellar nebulae that have a density and size sufficient to permit the formation of H2, molecular hydrogen. However, this molecule is difficult to detect, and the molecule most used to trace the H2 is CO (carbon monoxide). The ratio between CO luminosity and H2 mass is roughly constant, although there are reasons to doubt this assumption in observations of some other galaxies. In the Milky Way, molecular clouds account for roughly one-half...
Globular Cluster -- A globular cluster is a cluster of stars that is spherical in shape and extremely dense towards its core. Globular clusters are usually composed of hundreds of thousands of old stars, similar to the bulge of a spiral galaxy but confined to a volume of only a few cubic parsecs. Some globular clusters (like Omega Centauri in our Milky Way, and G1 in M31) are truly massive clusters, with several million times the mass of our Sun. Such globular clusters may be the...
