ScienceDaily: Dark Matter and Dark Energy News

Scientists size up universe's most lightweight dwarf galaxy

Mon, 10 Jun 2013 13:35:35 EDT

The least massive galaxy in the known universe has now been measured, clocking in at just 1,000 or so stars with a bit of dark matter holding them together.

Simple theory may explain mysterious dark matter

Mon, 10 Jun 2013 13:28:28 EDT

The reason dark matter, which makes up 85 percent of all the matter in the universe, is invisible could be because it possesses a rare, donut-shaped type of electromagnetism instead of the more exotic forces that have been proposed, according to an analysis by theoretic physicists.

Cosmic swirly straws: Galaxies fed by funnels of fuel

Fri, 24 May 2013 15:48:48 EDT

Computer simulations of galaxies growing over billions of years have revealed a likely scenario for how they feed: a cosmic version of swirly straws. The results show that cold gas -- fuel for stars -- spirals into the cores of galaxies along filaments, rapidly making its way to their "guts." Once there, the gas is converted into new stars, and the galaxies bulk up in mass.

Hubble tells a tale of galactic collisions

Sun, 12 May 2013 14:53:53 EDT

When we look into the distant cosmos, the great majority of the objects we see are galaxies: immense gatherings of stars, planets, gas, dust, and dark matter, showing up in all kind of shapes. A new Hubble picture registers several, but the galaxy catalogued as 2MASX J05210136-2521450 stands out at a glance due to its interesting shape.

Astronomers discover surprising clutch of hydrogen clouds lurking among our galactic neighbors

Wed, 08 May 2013 13:17:17 EDT

In a dark, starless patch of intergalactic space, astronomers have discovered a never-before-seen cluster of hydrogen clouds strewn between two nearby galaxies, Andromeda (M31) and Triangulum (M33). The researchers speculate that these rarefied blobs of gas -- each about as massive as a dwarf galaxy -- condensed out of a vast and as-yet undetected reservoir of hot, ionized gas, which could have accompanied an otherwise invisible band of dark matter.

New dark matter detector begins its search

Thu, 02 May 2013 18:53:53 EDT

Scientists heard their first pops this week in an experiment that searches for signs of dark matter in the form of tiny bubbles. Scientists will need further analysis to discern whether dark matter caused any of the COUPP-60 experiment’s first bubbles at the SNOLAB underground science laboratory.

Using black holes to measure the universe's rate of expansion

Mon, 22 Apr 2013 12:30:30 EDT

Scientists have developed a method that uses black holes to measure distances of billions of light years with a high degree of accuracy. The ability to measure these distances will allow scientists to see further into the past of the universe than ever before.

Dark lightning: Are airplane passengers exposed to radiation from intense bursts of gamma-rays from thunderclouds?

Wed, 10 Apr 2013 08:27:27 EDT

Scientists have known for almost a decade that thunderstorms are capable of generating brief but powerful bursts of gamma-rays called terrestrial gamma-ray flashes, or TGFs. Because they can originate near the same altitudes at which commercial aircraft routinely fly, scientists have been trying to determine whether or not terrestrial gamma ray flashes present a radiation hazard to individuals in aircraft. In the middle of the storm, radiation doses could be roughly equal to a full-body CT scan, preliminary research suggests.

Search for dark matter: Experiment measures antimatter excess in cosmic ray flux

Wed, 03 Apr 2013 11:53:53 EDT

The international team running the Alpha Magnetic Spectrometer (AMS) today announced the first results in its search for dark matter. They report the observation of an excess of positrons in the cosmic ray flux. The results are consistent with the positrons originating from the annihilation of dark matter particles in space, but not yet sufficiently conclusive to rule out other explanations.

Best map ever made of universe's oldest light: Planck mission brings universe into sharp focus

Thu, 21 Mar 2013 08:42:42 EDT

The Planck space mission has released the most accurate and detailed map ever made of the oldest light in the universe, revealing new information about its age, contents and origins.

Predicting key property in Andromeda's satellites

Thu, 14 Feb 2013 12:06:06 EST

Using modified laws of gravity, researchers have closely predicted a key property -- velocity dispersion -- measured in faint dwarf galaxies that are satellites of the nearby giant spiral galaxy Andromeda.

'A drop of ink on the luminous sky:' Wide Field Imager snaps cosmic gecko

Wed, 13 Feb 2013 08:24:24 EST

This part of the constellation of Sagittarius (The Archer) is one of the richest star fields in the whole sky -- the Large Sagittarius Star Cloud. The huge number of stars that light up this region dramatically emphasize the blackness of dark clouds like Barnard 86, which appears at the center of this new picture.

NASA's Jet Propulsion Laboratory to lead U.S. science team for dark energy mission

Tue, 12 Feb 2013 14:01:01 EST

The European Space Agency (ESA) has selected three NASA-nominated science teams to participate in their planned Euclid mission, including one team led by NASA's Jet Propulsion Laboratory in Pasadena, Calif.

Astronomers ask 'where are all the dwarf galaxies?'

Fri, 01 Feb 2013 09:03:03 EST

Astronomers have identified “Cosmic Web Stripping” as a new way of explaining the famous missing dwarf problem: the lack of observed dwarf galaxies compared with that predicted by the theory of Cold Dark Matter and Dark Energy.

NASA officially joins ESA's 'dark universe' mission

Thu, 24 Jan 2013 14:07:07 EST

NASA has joined the European Space Agency's (ESA's) Euclid mission, a space telescope designed to investigate the cosmological mysteries of dark matter and dark energy.

Revolutionary theory of dark matter

Thu, 24 Jan 2013 09:15:15 EST

The universe abounds with dark matter. Nobody knows what it consists of. Physicists in Norway have now come up with a mathematical explanation that could solve the mystery once and for all.

Setting the Dark on Fire: Beautiful view of clouds of cosmic dust in region of Orion

Wed, 23 Jan 2013 09:45:45 EST

In space, dense clouds of cosmic gas and dust are the birthplaces of new stars. In visible light, this dust is dark and obscuring, hiding the stars behind it. So much so that, when astronomer William Herschel observed one such cloud in the constellation of Scorpius in 1774, he thought it was a region empty of stars and is said to have exclaimed, "Truly there is a hole in the sky here!"

Dynamic, dark energy in an accelerating universe

Mon, 14 Jan 2013 09:25:25 EST

A new model is contributing towards understanding the nature of dark energy. If dark energy did not exist, the gravitational pull exerted by matter would slow down the expansion of the universe, but observations have concluded that the opposite is the case. Dark energy is what makes the universe expand in an accelerating way.

Detecting dusty clouds and stars: New radio wave technique uncovers shadows of clouds and stars in Milky Way's center

Mon, 07 Jan 2013 17:17:17 EST

Researchers have discovered a new tool for detecting dusty clouds and stars in the center of the Milky Way galaxy: simply take a picture using radio waves. Unlike in the optical, X-ray and infrared wavelengths, it is unusual to see a dark feature with radio waves. The technique has been used to identify so-called radio dark clouds and stars. Knowing details of these clouds is important because the clouds can produce stars.

Carbon in Vesta's craters: Asteroid impacts may have transferred carbonaceous material to protoplanet and inner solar system

Thu, 03 Jan 2013 13:09:09 EST

The protoplanet Vesta has been witness to an eventful past: images taken by the framing camera onboard NASA's space probe Dawn show two enormous craters in the southern hemisphere. The images were obtained during Dawn's year-long visit to Vesta that ended in September 2012. These huge impacts not only altered Vesta's shape, but also its surface composition. Scientists have shown that impacting small asteroids delivered dark, carbonaceous material to the protoplanet. In the early days of our solar system, similar events may have provided the inner planets such as Earth with carbon, an essential building block for organic molecules.

Are we closing in on dark matter?

Tue, 18 Dec 2012 14:29:29 EST

More than 100 cosmologists, particle physicists and observational astrophysicists are now united in the hunt to determine what is dark matter. Their goal: to take stock of the latest theories and findings about dark matter, assess just how close we are to detecting it and spark cross-disciplinary discussions and collaborations aimed at resolving the dark matter puzzle. So where do things stand?

Too much dark matter in galaxy cluster? 'Dark core' may not be so dark after all

Thu, 29 Nov 2012 13:06:06 EST

Astronomers were puzzled earlier this year when NASA's Hubble Space Telescope spotted an overabundance of dark matter in the heart of the merging galaxy cluster Abell 520. This observation was surprising because dark matter and galaxies should be anchored together, even during a collision between galaxy clusters.

Searching for elusive dark matter material

Thu, 15 Nov 2012 14:16:16 EST

Researchers are making key contributions to a physics experiment that will look for one of nature's most elusive particles, "dark matter," using a tank nearly a mile underground beneath the Black Hills of South Dakota.

BOSS quasars unveil a new era in the expansion history of the universe

Mon, 12 Nov 2012 22:43:43 EST

BOSS, the Baryon Oscillation Spectroscopic Survey, is mapping a huge volume of space to measure the role of dark energy in the evolution of the universe. BOSS is the largest program of the third Sloan Digital Sky Survey (SDSS-III) and has just announced the first major result of a new mapping technique, based on the spectra of over 48,000 quasars with redshifts up to 3.5, meaning that light left these active galaxies up to 11.5 billion years in the past.

Cassini Halloween treat: Titan glows in the dark

Wed, 31 Oct 2012 21:33:33 EDT

A literal shot in the dark by imaging cameras on NASA's Cassini spacecraft has yielded an image of a visible glow from Titan, emanating not just from the top of Titan's atmosphere, but also -- surprisingly -- from deep in the atmosphere through the moon's haze. A person in a balloon in Titan's haze layer wouldn't see the glow because it's too faint -- something like a millionth of a watt. Scientists were able to detect it with Cassini because the spacecraft's cameras are able to take long-exposure images.

CALIFA survey publishes intimate details of 100 galaxies

Wed, 31 Oct 2012 08:15:15 EDT

The Calar Alto Legacy Integral Field Area survey (CALIFA survey) has published a first set of data, offering views of one hundred galaxies in the local Universe at an unprecedented level of detail. The new data represent the first large-scale effort at "two plus one" mapping of galaxies: for every pixel within each two-dimensional image, a detailed ("spectral") analysis can be performed, providing information about dynamics and chemical composition. These, in turn, yield key information that will allow scientists to reconstruct the structure and dynamics of galaxies, as well as their evolution over time.

First direct detection sheds light on dark galaxies

Tue, 30 Oct 2012 16:12:12 EDT

Three lead members of an international science team provide insight into the first direct detection of dark galaxies.

Astronomers report that dark matter 'halos' may contain stars, disprove other theories

Wed, 24 Oct 2012 13:34:34 EDT

Do dark matter "halos" that make up most of the matter in the universe contain a small number of stars? Astronomers now make a case for that.

Poetry in motion: Gemini Observatory releases image of rare polar ring galaxy

Thu, 18 Oct 2012 18:59:59 EDT

Polar-ring galaxies are peculiar objects. Astronomers have found only a handful of them, so not much is known about their origins. Most have an early-type spiral system, called a lenticular galaxy, as the central showpiece. But NGC 660, which lies about 40 million light-years distant toward the direction of Pisces the Fishes, is the only polar-ring galaxy known with what is called a late-type lenticular galaxy as its host. All, however, display a ring of stars, dust, and gas that extends tens of thousands of light-years across space along an orbit nearly perpendicular to the main disk.

Dark matter filament studied in 3-D for the first time

Tue, 16 Oct 2012 09:22:22 EDT

Astronomers using the NASA/ESA Hubble Space Telescope have studied a giant filament of dark matter in 3D for the first time. Extending 60 million light-years from one of the most massive galaxy clusters known, the filament is part of the cosmic web that constitutes the large-scale structure of the Universe, and is a leftover of the very first moments after the Big Bang. If the high mass measured for the filament is representative of the rest of the Universe, then these structures may contain more than half of all the mass in the Universe.

When galaxies eat galaxies: Gravity lenses suggest big collisions make galaxies denser

Fri, 12 Oct 2012 08:21:21 EDT

Using gravitational "lenses" in space, astronomers have discovered that the centers of the biggest galaxies are growing denser -- evidence of repeated collisions and mergers by massive galaxies with 100 billion stars.

Mass of dark matter revealed by precise measurements of the galaxy

Fri, 05 Oct 2012 08:25:25 EDT

Astronomers have succeeded in precisely determining the astronomical yardstick for the Galaxy based upon precise distance measurements from advanced radio telescopes. The new findings are that the distance from the sun to the Galactic center is 26,100 light-years, and that the Galactic rotation velocity in the solar system is 240km/s.

Using artificial intelligence to chart the universe

Mon, 24 Sep 2012 08:03:03 EDT

Astronomers have developed an artificial intelligence algorithm to help them chart and explain the structure and dynamics of the universe around us with unprecedented accuracy. Scientists routinely use large telescopes to scan the sky, mapping the coordinates and estimating the distances of hundreds of thousands of galaxies and so enabling them to create a map of the large-scale structure of the Universe.

World’s most powerful digital camera opens eye, records first images in hunt for dark energy

Mon, 17 Sep 2012 10:46:46 EDT

Eight billion years ago, rays of light from distant galaxies began their long journey to Earth. That ancient starlight has now found its way to a mountaintop in Chile, where the newly-constructed Dark Energy Camera, the most powerful sky-mapping machine ever created, has captured and recorded it for the first time.

Dark energy is real, say astronomers

Wed, 12 Sep 2012 08:47:47 EDT

Dark energy, a mysterious substance thought to be speeding up the expansion of the Universe is really there, according to a team of astronomers. After a two-year study, scientists conclude that the likelihood of its existence stands at 99.996 per cent.

Mathematicians offer unified theory of dark matter, dark energy, altering Einstein field equations

Thu, 06 Sep 2012 09:20:20 EDT

A pair of mathematicians have proposed a unified theory of dark matter and dark energy that alters Einstein's equations describing the fundamentals of gravity. They suggest the law of energy and momentum conservation in spacetime is valid only when normal matter, dark matter and dark energy are all taken into account. For normal matter alone, energy and momentum are no longer conserved, they argue.

Big picture of the universe confirmed, WiggleZ survey of more than 200,000 galaxies shows

Tue, 21 Aug 2012 09:40:40 EDT

We know that stars group together to form galaxies, galaxies clump to make clusters and clusters gather to create structures known as superclusters. At what scale though, if at all, does this Russian doll-like structure stop? Scientists have been debating this very question for decades because clustering on large scales would be in conflict with our 'standard model' of cosmology. The current model is based on Einstein's equations assuming everything is smooth on the largest scales. If matter were instead clumpy on very large scales, then the entire model would need to be rethought.

Recreating a slice of the universe: Computational approach follows thousands of galaxies over billions of years

Wed, 15 Aug 2012 11:22:22 EDT

Scientists have invented a new computational approach that can accurately follow the birth and evolution of thousands of galaxies over billions of years. For the first time it is now possible to build a universe from scratch that brims with galaxies like we observe around us.

This is not a pipe: Curious dark Pipe Nebula seen as never before

Wed, 15 Aug 2012 08:27:27 EDT

Just as René Magritte wrote “This is not a pipe” on his famous painting, this is also not a pipe. It is however a picture of part of a vast dark cloud of interstellar dust called the Pipe Nebula. By coincidence this image is appearing on the 45th anniversary of the painter’s death.

Gamma rays from galactic center could be evidence of dark matter

Mon, 13 Aug 2012 15:55:55 EDT

Gamma-ray photons seen emanating from the center of the Milky Way galaxy are consistent with the intriguing possibility that dark-matter particles are annihilating each other in space, according to new research.

Plenty of dark matter near the Sun

Thu, 09 Aug 2012 09:04:04 EDT

Astronomers have found large amounts of invisible "dark matter" near the Sun. Their results are consistent with the theory that the Milky Way Galaxy is surrounded by a massive "halo" of dark matter, but this is the first study of its kind to use a method rigorously tested against mock data from high quality simulations. The authors also find tantalizing hints of a new dark matter component in our Galaxy.

First BOSS data: 3-D map of 500,000 galaxies, 100,000 quasars

Wed, 08 Aug 2012 09:38:38 EDT

Now available to the public: spectroscopic data from over 500,000 galaxies up to 7 billion light years away, over 100,000 quasars up to 11.5 billion light years away, and many thousands of other astronomical objects in the Sloan Digital Sky Survey's Data Release 9. This is the first data from BOSS, the Baryon Oscillation Spectroscopic Survey, the largest spectroscopic survey ever for measuring evolution of large-scale galactic structure.

New 3D map of massive galaxies and black holes offers clues to dark matter, dark energy

Wed, 08 Aug 2012 09:34:34 EDT

Astronomers have constructed the largest-ever three-dimensional map of massive galaxies and distant black holes, which will help the investigation of the mysterious “dark matter” and “dark energy” that make up 96 percent of the universe.

Theoretical physicists probe the Majorana mystery

Wed, 01 Aug 2012 11:35:35 EDT

Physicists close in on a subatomic particle that could enable the next generation of supercomputers and illuminate the inscrutability of cosmic dark matter.

Dark galaxies of the early universe spotted for the first time

Wed, 11 Jul 2012 07:42:42 EDT

Dark galaxies are small, gas-rich galaxies in the early Universe that are very inefficient at forming stars. They are predicted by theories of galaxy formation and are thought to be the building blocks of today's bright, star-filled galaxies. Astronomers think that they may have fed large galaxies with much of the gas that later formed into the stars that exist today.

Hubble unmasks ghost galaxies

Tue, 10 Jul 2012 13:31:31 EDT

Astronomers are studying some of the smallest and faintest galaxies in our cosmic neighborhood. These galaxies are fossils of the early Universe: They have barely changed for 13 billion years. The discovery could help explain the so-called "missing satellite" problem, where only a handful of satellite galaxies have been found around the Milky Way, against the thousands that are predicted by theories.

Milky Way struck 100 million years ago, still rings like a bell

Thu, 28 Jun 2012 17:45:45 EDT

Astronomers have discovered evidence that our Milky Way had an encounter with a small galaxy or massive dark matter structure perhaps as recently as 100 million years ago, and as a result of that encounter it is still ringing like a bell.

Reaching, researching between stars: Astronomers use Lonestar supercomputer to explore role of dark matter in galaxy formation

Tue, 26 Jun 2012 11:52:52 EDT

A new study reveals that dark matter is more distributed than predictions previously stated. Researchers used the TACC Lonestar supercomputer to simulate thousands of galaxy models based on the information retrieved at the McDonald Observatory and the National Aeronautics and Space Administration.

Compact blue dwarf can’t hide from Hubble

Tue, 19 Jun 2012 10:51:51 EDT

The NASA/ESA Hubble Space Telescope has captured a new view of the dwarf galaxy UGC 5497, which looks a bit like salt sprinkled on black velvet in the image.

Black hole growth found to be out of sync

Mon, 11 Jun 2012 19:46:46 EDT

New evidence from NASA's Chandra X-ray Observatory challenges prevailing ideas about how black holes grow in the centers of galaxies. Astronomers long have thought that a supermassive black hole and the bulge of stars at the center of its host galaxy grow at the same rate -- the bigger the bulge, the bigger the black hole. However, a new study of Chandra data has revealed two nearby galaxies with supermassive black holes that are growing faster than the galaxies themselves.

More atomic hydrogen gas lurks in universe: There's more star-stuff out there, but it's not dark matter

Wed, 30 May 2012 11:58:58 EDT

More atomic hydrogen gas -- the ultimate fuel for stars -- is lurking in today's universe than we thought, astronomers have found. This is the first accurate measurement of this gas in galaxies close to our own.

Baby galaxies grew up quickly

Wed, 16 May 2012 12:02:02 EDT

Baby galaxies from the young universe more than 12 billion years ago evolved faster than previously thought, shows new research. This means that already in the early history of the universe, there was potential for planet formation and life.

Under 'dark halo' old galaxies have many more stars

Tue, 01 May 2012 21:14:14 EDT

Some of the oldest galaxies in the Universe have three times more stellar mass, and so many more stars, than all current models of galaxy evolution predict.

Vast structure of satellite galaxies discovered: Do the Milky Way’s companions spell trouble for dark matter?

Wed, 25 Apr 2012 09:43:43 EDT

Astronomers have discovered a vast structure of satellite galaxies and clusters of stars surrounding our Galaxy, stretching out across a million light years. The work challenges the existence of dark matter, part of the standard model for the evolution of the universe.

Serious blow to dark matter theories? New study finds mysterious lack of dark matter in Sun's neighborhood

Wed, 18 Apr 2012 11:19:19 EDT

The most accurate study so far of the motions of stars in the Milky Way has found no evidence for dark matter in a large volume around the Sun. According to widely accepted theories, the solar neighborhood was expected to be filled with dark matter, a mysterious invisible substance that can only be detected indirectly by the gravitational force it exerts. But a new study by a team of astronomers in Chile has found that these theories just do not fit the observational facts. This may mean that attempts to directly detect dark matter particles on Earth are unlikely to be successful.

On the border between matter and anti-matter: Nanoscientists find long-sought Majorana particle

Fri, 13 Apr 2012 16:00:00 EDT

Scientists in the Netherlands have succeeded for the first time in detecting a Majorana particle. In the 1930s, Italian physicist Ettore Majorana deduced from quantum theory the possibility of the existence of a very special particle, a particle that is its own anti-particle: the Majorana fermion. That 'Majorana' would be right on the border between matter and anti-matter.

First-ever model simulation of the structuring of the observable universe

Thu, 12 Apr 2012 13:30:30 EDT

Astronomers have performed the first-ever computer model simulation of the structuring of the entire observable universe, from the Big Bang to the present day. The simulation has made it possible to follow the evolution of 550 billion particles. This simulation, along with the two additional runs expected by late May 2012, will provide outstanding support for future projects dedicated to the observation and mapping of the universe. These simulations will shed light on the nature of dark energy and its effects on cosmic structure formation, and hence on the distribution of dark matter and galaxies in the universe.

Discovery of the Musket Ball Cluster, a system of colliding galaxy clusters

Thu, 12 Apr 2012 11:37:37 EDT

Using a combination of powerful observatories in space and on the ground, astronomers have observed a violent collision between two galaxy clusters in which so-called normal matter has been wrenched apart from dark matter through a violent collision between two galaxy clusters.

Dwarf galaxies provide new insights on dark matter

Mon, 02 Apr 2012 18:53:53 EDT

Scientists have looked for signals from dark matter by zeroing in on 10 small, faint galaxies that orbit our own. Although no signals have been detected, a novel analysis technique applied to two years of data from the observatory's Large Area Telescope has essentially eliminated these particle candidates for the first time.

South Pole telescope homes in on dark energy, neutrinos

Mon, 02 Apr 2012 09:31:31 EDT

Analysis of data from the 10-meter South Pole Telescope is providing new support for the most widely accepted explanation of dark energy -- the source of the mysterious force that is responsible for the accelerating expansion of the universe.