Latest Galaxy formation and evolution Stories

2010-05-26 09:21:45

A surprising discovery that hydrogen gas clouds found in abundance in and above our Milky Way Galaxy have preferred locations has given astronomers a key clue about the origin of such clouds, which play an important part in galaxy evolution. "We've concluded that these clouds are gas that has been blown away from the Galaxy's plane by supernova explosions and the fierce winds from young stars in areas of intense star formation," said H. Alyson Ford of the University of Michigan, whose Ph.D...

2010-05-11 10:00:00

Supermassive black holes with the mass of many millions of stars have been detected at the center of many large galaxies. A super-massive black hole acts like a lurking "monster" at the center of the galaxy which swallows the surrounding material through the intensity of its gravitational pull. X-ray observations indicate that a large amount of energy is produced by the in-fall of matter into a black hole, and ejected in powerful jets. Astronomers from the Max Planck Institute for...

2010-05-05 09:05:00

A new wide-field image released today by ESO displays many thousands of distant galaxies, and more particularly a large group belonging to the massive galaxy cluster known as Abell 315. As crowded as it may appear, this assembly of galaxies is only the proverbial "tip of the iceberg", as Abell 315 "” like most galaxy clusters "” is dominated by dark matter. The huge mass of this cluster deflects light from background galaxies, distorting their observed shapes slightly. When...

2010-04-20 07:33:08

Scientists at the Naval Research Laboratory have solved a long-standing dilemma about the mass of infrared bright merging galaxies. Because galaxies are the largest directly observable objects in the universe, learning more about their formation is key to understanding how the universe works. Dr. Barry Rothberg and Dr. Jacqueline Fischer, both of the Infrared-Submillimeter Astrophysics & Techniques Section in the Remote Sensing Division, used new data from the 8-meter Gemini-South...

2010-04-16 06:40:00

Black holes are thought to reside at the center of almost every galaxy, with some growing to more than a billion times the mass of the Sun. Now a team of UK astronomers believe that these supermassive black holes are commonplace, release more than enough energy to strip their host galaxies apart and in the process shut down these galaxies' star formation for good. On Friday April 16th, team member Asa Bluck of the University of Nottingham, who led this research, will explain the dramatic...

2010-03-22 07:40:00

About 23% of the Universe is made up of mysterious "Ëœdark matter', invisible material only detected through its gravitational influence on its surroundings. Now two astronomers based at the National Autonomous University of Mexico (UNAM) have found a hint of the way it behaves near black holes. Their results appear in a letter in the journal Monthly Notices of the Royal Astronomical Society. In the early Universe clumps of dark matter are thought to have attracted gas, which then...

2010-03-21 13:55:00

Scientists have found a massive galaxy in the early Universe creating stars like our sun up to 100 times faster than the modern-day Milky Way. The team of international researchers, led by Durham University, described the finding as like seeing "a teenager going through a growth spurt". Due to the amount of time it takes light to reach Earth the scientists observed the galaxy as it would have appeared 10 billion years ago "“ just three billion years after the Big Bang. They found four...

2010-03-04 09:15:32

Located half a billion light-years from Earth, ESO 306-17, is a large, bright elliptical galaxy in the southern sky of a type known as a fossil group. Astronomers use this term to emphasize the isolated nature of these galaxies. However, are they like fossils "” the last remnants of a once active community "” or is it more sinister than that? Did ESO 306-17 gobble up its next-door neighbors? Gravity brings galaxies together and bigger ones swallow smaller ones. There is evidence...

2010-03-01 13:30:00

A team of astronomers using NASA's Hubble Space Telescope and other space instruments has discovered that a collection of small, ancient galaxies, called the Hickson Compact Group 31 (HCG 31), finally is coming together into one larger galaxy after 10 billion years. The images the team recorded offer a window into the universe's early years, when the buildup of large galaxies from smaller building blocks was common. According to Jane Charlton, a Penn State professor of astronomy and...

2010-02-25 12:30:00

Lowell Observatory astronomer Deidre Hunter and her team studies small, diffuse galaxies to learn about star formation in those regions and, perhaps, shed light on the birth of the first stars after the Big Bang When you picture a galaxy in your mind's eye, it's often a spiral with magnificent structure--long, swirling, milky-white arms of stars and gas. Lowell Observatory astronomer Deidre Hunter has spent most of the last 17 years methodically studying galaxies that you might not...

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...

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