Latest Galaxy formation and evolution Stories

GALEX Finds Stellar Extremophiles
2011-11-08 10:03:53

[ Watch the Video ] Back in the 1970s, biologists were amazed to discover a form of life they never expected.  Tiny microorganisms with ancient DNA were living in the hot springs of Yellowstone National Park.  Instead of dissolving in the boiling waters, the microbes were thriving, ringing the springs with vibrant color. Scientists coined the term extremophile, which means "extreme-loving", to describe the creatures--and the hunt was on for more.  Soon, extremophiles were...

Image Release: Close Encounters Of The Galactic Kind
2011-10-26 02:54:11

Astronomers have used a large survey to test a prediction that close encounters between galaxies can trigger the rapid growth of supermassive black holes. Key to this work was Chandra's unique ability to pinpoint actively growing black holes through the X-rays they generate. The researchers looked at 562 pairs of galaxies ranging in distances from about 3 billion to 8 billion light years from Earth. They found that the galaxies in the early stages of an encounter with another were more...

Study Deepens Dark Matter Mystery
2011-10-17 13:15:18

Like all galaxies, our Milky Way is home to a strange substance called dark matter. Dark matter is invisible, betraying its presence only through its gravitational pull. Without dark matter holding them together, our galaxy's speedy stars would fly off in all directions. The nature of dark matter is a mystery -- a mystery that a new study has only deepened. "After completing this study, we know less about dark matter than we did before," said lead author Matt Walker, a Hubble Fellow at the...

Image 1 - Suspects Exonerated In The Quenching Of Star Formation
2011-10-12 04:23:27

Supermassive black holes millions to billions times the mass of our Sun lie at the heart of most, maybe all large galaxies. Some of these power brilliantly luminous, rapidly growing objects called active galactic nuclei that gather and condense enormous quantities of dust, gas and stars. Because astronomers had seen these objects primarily in the oldest, most massive galaxies that glow with the red light of aging stars, many thought active galactic nuclei might help to bring an end to the...

Milky Way's Spiral Arms Created By Collision With Another Galaxy
2011-09-15 09:56:33

  The Milky Way's trademark features, its iconic spiral arms, were likely formed when the galaxy collided with the Sagittarius Dwarf galaxy, researchers announced on Thursday. In their study, University of Pittsburgh postdoctoral research associate Christopher W. Purcell and colleagues were the first to use supercomputers to re-create repeated collisions between the two galaxies, which scientists previously believed had little impact on the Milky Way. According to a University...

2011-08-30 06:40:13

A team of scientists, led by Michael Rauch from the Carnegie Observatories, has discovered a distant galaxy that may help elucidate two fundamental questions of galaxy formation: How galaxies take in matter and how they give off energetic radiation. Their work will be published in the Monthly Notices of the Royal Astronomical Society. During the epoch when the first galaxies formed, it is believed that they radiated energy, which hit surrounding neutral hydrogen atoms and excited them to...

Spiral galaxy top view
2011-08-29 11:32:12

  Researchers at the University of California, Santa Cruz have used a supercomputer to create a spiral galaxy that matches our own Milky Way galaxy. The computer simulation is part of a physics project involving galaxy formation and evolution. "Previous efforts to form a massive disk galaxy like the Milky Way had failed, because the simulated galaxies ended up with huge central bulges compared to the size of the disk," Javiera Guedes, a graduate student in astronomy and...

2011-08-26 07:01:14

  A galaxy with a combination of characteristics never seen before is giving astronomers a tantalizing peek at processes they believe played key roles in the growth of galaxies and clusters of galaxies early in the history of the Universe. The galaxy, dubbed Speca by the researchers, is only the second spiral, as opposed to elliptical, galaxy known to produce large, powerful jets of subatomic particles moving at nearly the speed of light. It also is one of only two galaxies to show...

2011-08-22 16:37:42

A CSIRO study has shown why the lights are going out in the Universe. The Universe forms fewer stars than it used to, and a CSIRO study has now shown why - the galaxies are running out of gas. Dr. Robert Braun (CSIRO Astronomy and Space Science) and his colleagues used CSIRO´s Mopra radio telescope near Coonabarabran, NSW, to study far-off galaxies and compare them with nearby ones. Light (and radio waves) from the distant galaxies has taken time to travel to us, so we see the...

Latest Galaxy formation and evolution Reference Libraries

2010-09-13 16:56:08

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...

2010-09-07 17:03:18

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...

2004-10-19 04:45:42

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...

2004-10-19 04:45:41

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...

2004-10-19 04:45:41

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...

More Articles (9 articles) »
Word of the Day
  • The unit of magnetic flux density in the International System of Units, equal to the magnitude of the magnetic field vector necessary to produce a force of one newton on a charge of one coulomb moving perpendicular to the direction of the magnetic field vector with a velocity of one meter per second. It is equivalent to one weber per square meter.
This word is named for Nikola Tesla, the inventor, engineer, and futurist.