(PhysOrg.com) Astronomers have put forward a new theory about why black holes become so hugely massive – claiming some of them have no 'table manners', and tip their 'food' directly into their mouths, eating more than one course simultaneously.
(PhysOrg.com) -- ESA's Herschel Space Observatory is helping unravel the mystery of where cosmic dust comes from. Thanks to the resolution and sensitivity of Herschel, astronomers have been able to detect cosmic dust from a supernovae, adding weight to the theory that these cosmic fireworks are responsible for its creation.
The origin of the dust is important because it plays a crucial role in the formation of stars, particularly billions of years ago when star formation was at its peak. Galaxies like our own Milky Way are not simply collections of stars, but also contain clouds of gas and dust, crucial to the formation of new stars.
"Interestingly, this brand new clue does not come from observations of very distant galaxies, but from one of our closest galactic neighbours," comments Mikako Matsuura from UCL (University College London), who led a recent st... Read more »
One of a number of seemingly implausible features of dark energy is that its density is assumed to be constant over time. So, even though the universe expands over time, dark energy does not become diluted, unlike the rest of the contents of the universe.
As the universe expands, it seems that more dark energy appears out of nowhere to sustain the constant dark energy density of the universe. So, as times goes by, dark energy will become an increasingly dominant proportion of the observable universe – remembering that it is already estimated as being 73% of it.
(PhysOrg.com) -- A team of European astronomers has used ESO’s Very Large Telescope and a host of other telescopes to discover and study the most distant quasar found to date. This brilliant beacon, powered by a black hole with a mass two billion times that of the Sun, is by far the brightest object yet discovered in the early Universe. The results will appear in the 30 June 2011 issue of the journal Nature.
"This quasar is a vital probe of the early Universe. It is a very rare object that will help us to understand how supermassive black holes grew a few hundred million years after the Big Bang," says Stephen Warren, the study's team leader.
Quasars are very bright, distant galaxies that are believed to be powered by supermassive black holes at their centres. Their brilliance makes them powerful beacons that may help to probe the era when the first stars and g... Read more »
(PhysOrg.com) -- All planets move around their stars in
the same direction as the star spins—at least that’s what we thought.
But now Australian National University astronomer Dr. Daniel Bayliss and
his colleagues have found a planet that breaks the mold.
Dr. Bayliss, from the Research School of Astronomy and Astrophysics, is
one of 16 early-career scientists unveiling their research to the public
at Fresh Science – a national program sponsored by the Australian
Government.
(PhysOrg.com) -- A new image from NASA's Chandra and Spitzer
space telescopes shows the dusty remains of a collapsed star. The dust
is flying past and engulfing a nearby family of stars.
"Scientists think the stars in the image are part of a stellar
cluster in which a supernova exploded," said Tea Temin of the
Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass., who led
the study. "The material ejected in the explosion is now blowing past
these stars at high velocities."
The researchers, led by Durham University's Department of Physics,
observed the massive galaxy as it would have appeared
just three billion years after the Big Bang when the Universe was a
quarter of its present age.
According to their findings the galaxy exploded in a series of blasts
trillions of times more powerful than any caused by an atomic bomb. The
blasts happened every second for millions of years, the scientists
said.
The explosions scattered the gas needed to form new stars by helping
it escape the gravitatio... Read more »
ScienceDaily (Feb. 26, 2010) — As many as one
quarter of the star clusters in our Milky Way -- many more than
previously thought -- are invaders from other galaxies, according to a
new study. The report also suggests there may be as many as six dwarf
galaxies yet to be discovered within the Milky Way rather than the two
that were previously confirmed.
Since WISE began its scan of the entire sky in infrared light on Jan. 14, the space telescope has beamed back more than a quarter of a million raw, infrared images.
Four new, processed pictures illustrate a sampling of the mission's
targets -- a wispy comet, a bursting star-forming cloud, the grand Andromeda galaxy and a faraway cluster of hundreds of galaxies.
"WISE has worked superbly," said Ed Weiler, associate administrator
of the Science Mission Directorate at NASA Headquarters in Washington.
"These first images are... Read more »
(PhysOrg.com) -- For the first time, astronomers have found a
supernova explosion with properties similiar to a gamma-ray burst, but
without seeing any gamma rays from it. The discovery, using the
National Science Foundation's Very Large Array (VLA) radio telescope,
promises, the scientists say, to point the way toward locating many
more examples of these mysterious explosions.
We think that radio observations will soon be a more powerful tool for finding this kind of supernova in the nearby Universe than gamma-ray satellites," said Alicia Soderberg, of the Harvard-Smithsonian Center for Astrophysics.
The telltale clue came when the radio obse... Read more »
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