Latest Galaxies Stories

More than half of the largest galaxies in the nearby universe have collided and merged with another galaxy in the past two billion years, according to a Yale astronomer in a study using hundreds of images from two of the deepest sky surveys ever conducted. The idea of large galaxies being assembled primarily by mergers rather than evolving by themselves in isolation has grown to dominate cosmological thinking. However, a troubling inconsistency within this general theory has been that the...

NASA -- The supermassive black hole at the center of the Milky Way has surprisingly helped spawn a new generation of stars, according to observations from NASA's Chandra X-ray Observatory. This novel mode of star formation may solve several mysteries about the supermassive black holes that reside at the centers of nearly all galaxies."Massive black holes are usually known for violence and destruction," said Sergei Nayakshin of the University of Leicester, United Kingdom, and...

SANTA CRUZ, CA -- According to the prevailing "cold dark matter" theory of the evolution of the universe, every galaxy is surrounded by a halo of dark matter that can only be detected indirectly by observing its gravitational effects. This theory faced a challenge in 2003, when a team of astronomers reported a surprising absence of dark matter in elliptical galaxies. But a new analysis published in the September 29 issue of the journal Nature provides an explanation for the earlier...

WASHINGTON (Reuters) - A supermassive black hole appears to be homeless in the cosmos without a galaxy to nestle in, Hubble Space Telescope scientists reported on Wednesday. Most monster black holes lurk at the heart of massive galaxies, slurping up matter from the galactic center with a pull so strong that nothing, not even light, can escape. But a team of European astronomers reported in the journal Nature that a particular black hole some 5 billion light-years away has no evidence...

IOP -- A research group at Cambridge think that the universe might once have been packed full of tiny black holes. Dr Martin Haehnelt, a researcher in the group led by Astronomer Royal Martin Rees, will present new evidence to support this controversial idea at the Institute of Physics conference Physics 2005 in Warwick. Most cosmologists believe that supermassive black holes grew up in big galaxies, accumulating mass as time went on. But Haehnelt says there is increasing evidence for a...

RAS -- Scientists from the University of Durham may have solved a decades-old puzzle regarding the distribution of the eleven small satellite galaxies that surround the Milky Way. The Milky Way is not alone. It is surrounded by a retinue of small "dwarf galaxy" companions. Cosmological theory predicts that these galaxies should occupy a large, nearly spherical halo but observations show that the satellite galaxies have a bizarre flattened, pancake-like distribution. The Durham team...

Chandra -- Distant galaxies undergoing intense bursts of star formation have been shown by NASA's Chandra X-ray Observatory to be fertile growing grounds for the largest black holes in the Universe. Collisions between galaxies in the early Universe may be the ultimate cause for both the accelerated star formation and black hole growth.By combining the deepest X-ray image ever obtained with submillimeter and optical observations, an international team of scientists has found evidence that some...

NASA -- Peculiar outbursts of X-rays coming from a black hole have provided evidence that it has a mass of about 10,000 Suns, which would place it in a possible new class of black holes. The timing and regularity of these outbursts, observed with NASA's Chandra X-ray Observatory, make the object one of the best candidates yet for a so-called intermediate-mass black hole.Scientists have strong evidence for the existence of stellar black holes that are about 10 times as massive as the Sun. They...

NASA -- The very largest black holes reach a certain point and then grow no more, according to the best survey to date of black holes made with NASA's Chandra X-ray Observatory. Scientists have also discovered many previously hidden black holes that are well below their weight limit. These new results corroborate recent theoretical work about how black holes and galaxies grow. The biggest black holes, those with at least 100 million times the mass of the Sun, ate voraciously during the early...

Results explain supermassive black holes and star distribution in nearby galaxiesUsing a new computer model of galaxy formation, researchers have shown that growing black holes release a blast of energy that fundamentally regulates galaxy evolution and black hole growth itself. The model explains for the first time observed phenomena and promises to deliver deeper insights into our understanding of galaxy formation and the role of black holes throughout cosmic history, according to its...