Latest Galaxy formation and evolution Stories

2011-01-05 07:50:00

What happens when galaxies crash together? For years, these cosmic collisions have been blamed for triggering violent outbursts at the hearts of galaxies. Now, a remarkable piece of detective work has given a verdict: galactic mergers do not usually whet the appetite of the black holes that power these active galactic nuclei, meaning other, less dramatic phenomena are responsible. Most galaxies, including our own, have a huge but well-behaved black hole at their heart, while some have messy...

2010-12-20 14:57:21

A new study from NASA's Chandra X-ray Observatory tells scientists how often the biggest black holes have been active over the last few billion years. The object could help scientists better understand how massive stars explode, which ones leave behind black holes or neutron stars, and how many black holes are in our galaxy and others. This discovery clarifies how supermassive black holes grow and could have implications for how the giant black hole at the center of the Milky Way will behave...

2010-12-17 06:35:00

A UK-led international team of astronomers have presented the first conclusive evidence for a dramatic surge in star birth in a newly discovered population of massive galaxies in the early Universe. Their measurements confirm the idea that stars formed most rapidly about 11 billion years ago, or about three billion years after the Big Bang, and that the rate of star formation is much faster than was thought. The scientists used the European Space Agency's Herschel Space Observatory, an...

2010-11-25 08:35:00

The Andromeda Galaxy was formed as the result of a massive collision involving two separate galaxies that occurred billions of years ago, an international team of researchers has discovered. The astronomers, led by Francois Hammer of the Paris Observatory, conducted complex computer simulations of the galaxy's structural formation, both in France and at the National Astronomical Observatory of China (NAOC). They then analyzed the results and prepared a study, which has been published in the...

2010-11-24 14:24:23

Astronomers have caught sight of an unusual galaxy that has illuminated new details about a celestial "sandbar" connecting two massive islands of galaxies. The research was conducted in part with NASA's Spitzer Space Telescope. These "sandbars," or filaments, are known to span vast distances between galaxy clusters and form a lattice-like structure known as the cosmic web. Though immense, these filaments are difficult to see and study in detail. Two years ago, Spitzer's infrared eyes revealed...

2010-11-23 11:14:41

Astronomers find cosmic dust annoying when it blocks their view of the heavens, but without it the universe would be devoid of stars. Cosmic dust is the indispensable ingredient for making stars and for understanding how primordial diffuse gas clouds assemble themselves into full"“blown galaxies. "Formation of galaxies is one of the biggest remaining questions in astrophysics," said Andrey Kravtsov, associate professor in astronomy & astrophysics at the University of Chicago....

2010-11-18 09:53:02

Elliptical galaxies were once thought to be aging star cities whose star-making heyday was billions of years ago. But new observations with NASA's Hubble Space Telescope are helping to show that elliptical galaxies still have some youthful vigor left, thanks to encounters with smaller galaxies. Images of the core of NGC 4150, taken in near-ultraviolet light with the sharp-eyed Wide Field Camera 3 (WFC3), reveal streamers of dust and gas and clumps of young, blue stars that are significantly...

2010-11-10 10:25:00

European Southern Observatory astronomers have produced a spectacular new image of the famous Atoms-for-Peace galaxy (NGC 7252). This galactic pile-up, formed by the collision of two galaxies, provides an excellent opportunity for astronomers to study how mergers affect the evolution of the Universe. Atoms-for-Peace is the curious name given to a pair of interacting and merging galaxies that lie around 220 million light-years away in the constellation of Aquarius. It is also known as NGC 7252...

2010-10-15 11:11:41

OSU's Kazantzidis studies the behavior of galaxies, black holes through modeling & simulation at the Ohio Supercomputer Center An Ohio State University astronomer is working to unlock some of the mysteries surrounding the formation of vast galaxies and the evolution of massive black holes with his own large constellation of silicon wafers. Over the last year, two research teams led by Stelios Kazantzidis, a Long-Term Fellow at the Center for Cosmology and Astro-Particle Physics (CCAPP) at...

2010-10-13 14:09:46

New observations from ESO's Very Large Telescope have, for the first time, provided direct evidence that young galaxies can grow by sucking in the cool gas around them and using it as fuel for the formation of many new stars. In the first few billion years after the Big Bang the mass of a typical galaxy increased dramatically and understanding why this happened is one of the hottest problems in modern astrophysics. The results appear in the October 14 issue of the journal Nature. The first...

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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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.