Tag: strong (page 3 of 22)

Citizen Scientists Find Green Blobs in Hubble Galaxy Shots

April 3, 2015 / / 0 Comments





Excerpt from wired.com

In 2007, A Dutch schoolteacher named Hanny var Arkel discovered a weird green glob of gas in space. Sifting through pictures of galaxies online, as part of the citizen science project Galaxy Zoo, she saw a cloud, seemingly glowing, sitting next to a galaxy. Intrigued, astronomers set out to find more of these objects, dubbed Hanny’s Voorwerp (“Hanny’s object” in Dutch). Now, again with the help of citizen scientists, they’ve found 19 more of them, using the Hubble space telescope to snap the eight haunting pictures in the gallery above.



Since var Arkel found the first of these objects, hundreds more volunteers have swarmed to help identify parts of the universe in the Galaxy Zoo gallery. To find this new set, a couple hundred volunteers went through nearly 16,000 pictures online (seven people went through all of them), clicking yes/no/maybe as to whether they saw a weird green blob. Astronomers followed up on the galaxies they identified using ground-based telescopes, and confirmed 19 new galaxies surrounded by green gas.



What causes these wispy tendrils of gas to glow? Lurking at the center of each of these galaxies is a supermassive black hole, millions to billions times as massive as the sun, with gravity so strong that even light can’t escape them. As nearby gas and dust swirls into the black hole, like water circling a drain, that material heats up, producing lots of radiation—including powerful ultraviolet. Beaming out from the galaxy, that ultraviolet radiation strikes nearby clouds of gas, left over from past collisions between galaxies. And it makes the clouds glow an eerie green. “A lot of these bizarre forms we’re seeing in the images arise because these galaxies either interacted with a companion or show evidence they merged with a smaller galaxy,” says William Keel, an astronomer at the University of Alabama, Tuscaloosa.



The eight in this gallery, captured with Hubble, are especially weird. That’s because the quasar, the black-hole engine that’s supposed to be churning out the ultraviolet radiation, is dim—too dim, in fact, to be illuminating the green gas. Apparently, the once-bright quasar has faded. But because that UV light takes hundreds of thousands of years to travel, it can continue to illuminate the gas long after its light source has died away.  


Hubble finds phantom objects close to dead quasars

That glowing gas can tell astronomers a lot about the quasar that brought it to light. “What I’m so excited about is the fact that we can use them to do archaeology,” says Gabriela Canalizo, an astronomer at the University of California, Riverside, who wasn’t part of the new research. Because the streaks of gas are so vast, stretching up to tens of thousands of light years, the way they glow reveals the history of the radiation coming from the quasar. As the quasar fades, so will the gas’s glow, with the regions of gas closer to the quasar dimming first. By analyzing how the glow dwindles with distance from the quasar, astronomers can determine how fast the quasar is fading. “This was something we’ve never been able to do,” Canalizo says.

Measuring how fast the quasar fades allows astronomers to figure out exactly what’s causing it to turn off in the first place. “What makes them dim is running out of material to eat,” Canalizo says. That could happen if the quasar is generating enough radiation to blow away all the gas and dust surrounding the black hole—the same gas and dust that feeds it. Without a steady diet, the quasar is powerless to produce radiation. Only if more gas happens to make its way toward the black hole can the quasar turn on again. The glowing gas can provide details of this process, and if other mechanisms are at play.

With more powerful telescopes, astronomers will likely find many more. Hanny’s Verwoort, it turns out, may not be that weird after all.

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Black Holes, the Large Hadron Collider, & Finding Parallel Universes

March 27, 2015 / / 0 Comments

Excerpt from huffingtonpost.comI am a huge science enthusiast and an unabashed science fiction fan. There are tons of really cool stories out there that fire the imagination and even inspire young people to go into science. (I know they did me.) ...

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You don’t get rich writing a lot of checks? or, living evidence of a soul’s incarnate blueprint ~ Greg Giles

March 22, 2015 / / 0 Comments

Evidence suggests its easier for the wealthy to take candy from a babyAlthough the following video presentation, entitled, 5 Reasons Being Rich Can Make You A Bad Person, does not explore possibilities beyond our current physical reality, I feel the st...

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Powerful solar storm sparks stunning aurora around the world ~ Images of the Northern Lights 2015

March 18, 2015 / / 0 Comments

Excerpt from cnn.com  A severe solar storm created a stunning display of light in the night sky over parts of the United States, Europe, Australia and New Zealand early Wednesday morning, spotted by those lucky enough to be awake in the wee h...

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Rare & severe geomagnetic storm enables Aurora Borealis to be seen from U.S. tonight

March 17, 2015 / / 0 Comments

Excerpt from mashable.com Thanks to a rare, severe geomagnetic storm, the Northern Lights may be visible on Tuesday night in areas far to the south of its typical home in the Arctic.  The northern tier of the U.S., from Washington State to Michiga...

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Habitable’ Super-Earth Might Exist After All

March 9, 2015 / / 0 Comments


Artist's impression of Gliese 581d, a controversial exoplanet that may exist only 20 light-years from Earth.



Excerpt from news.discovery.com

Despite having discovered nearly 2,000 alien worlds beyond our solar system, the profound search for exoplanets — a quest focused on finding a true Earth analog — is still in its infancy. It is therefore not surprising that some exoplanet discoveries aren’t discoveries at all; they are in fact just noise in astronomical data sets.

But when disproving the existence of extrasolar planets that have some characteristics similar to Earth, we need to take more care during the analyses of these data, argue astronomers from Queen Mary, University of London and the University of Hertfordshire.

In a paper published by the journal Science last week, the researchers focus on the first exoplanet discovered to orbit a nearby star within its habitable zone.

Revealed in 2009, Gliese 581d hit the headlines as a “super-Earth” that had the potential to support liquid water on its possibly rocky surface. With a mass of around 7 times that of Earth, Gliese 581d would be twice as big with a surface gravity around twice that of Earth. Though extreme, it’s not such a stretch of the imagination that such a world, if it is proven to possess an atmosphere and liquid ocean, that life could take hold.

And the hunt for life-giving alien worlds is, of course, the central motivation for exoplanetary studies.

But the exoplanet signal has been called into doubt.
Gliese 581d’s star, Gliese 581, is a small red dwarf around 20 light-years away. Red dwarfs are known to be tempestuous little stars, often generating violent flaring outbursts and peppered in dark features called starspots. To detect the exoplanet, astronomers measured the very slight frequency shift (Doppler shift) of light from the star — as the world orbits, it exerts a tiny gravitational “tug”, causing the star to wobble. When this periodic wobble is detected, through an astronomical technique known as the “radial velocity method,” a planet may be revealed.

Last year, however, in a publication headed by astronomers at The Pennsylvania State University, astronomers pointed to the star’s activity as an interfering factor that may have imitated the signal from an orbiting planet when in fact, it was just noisy data.

But this conclusion was premature, argues Guillem Anglada-Escudé, of Queen Mary, saying that “one needs to be more careful with these kind of claims.”

“The existence, or not, of GJ 581d is significant because it was the first Earth-like planet discovered in the ‘Goldilocks’-zone around another star and it is a benchmark case for the Doppler technique,” said Anglada-Escudé in a university press release. “There are always discussions among scientists about the ways we interpret data but I’m confident that GJ 581d has been in orbit around Gliese 581 all along. In any case, the strength of their statement was way too strong. If the way to treat the data had been right, then some planet search projects at several ground-based observatories would need to be significantly revised as they are all aiming to detect even smaller planets.”

The upshot is that this new paper challenges the statistical technique used in 2014 to account for the signal being stellar noise — focusing around the presence of starspots in Gliese 581′s photosphere.

Gliese 581d isn’t the only possible exoplanet that exists around that star — controversy has also been created by another, potentially habitable exoplanet called Gliese 581g. Also originally detected through the wobble of the star, this 3-4 Earth mass world was found to also be in orbit within the habitable zone. But its existence has been the focus of several studies supporting and discounting its presence. Gliese 581 is also home to 3 other confirmed exoplanets, Gliese 581e, b and c.

Currently, observational data suggests Gliese 581g was just noise, but as the continuing debate about Gliese 581d is proving, this is one controversy that will likely keep on rumbling in the scientific journals for some time.

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Warp in spacetime lets astronomers watch the same star explode four times

March 8, 2015 / / 0 Comments



Excerpt from csmonitor.com

Thanks to a phenomenon known as gravitational lensing, the Hubble Space Telescope has captured four images of the same supernova explosion.

For the first time, a cosmic magnifying glass has allowed scientists to see the same star explosion four times, possibly offering a revealing glimpse into these explosive stellar deaths and the nature of the accelerating universe.

Astronomers using the Hubble Space Telescope have captured four images of a supernova explosion in deep space thanks to a galaxy located between Earth and the massive star explosion. You can see how Hubble saw the supernova in this NASA video. The galaxy cluster warped the fabric of space and time around it — like a bowling ball placed on a bed sheet — allowing scientists to see the supernova in four images.

"It was predicted 50 years ago that a supernova could be gravitationally lensed like this, but it's taken a long time for someone to find an example," lead study author Patrick Kelly, an astronomer at the University of California, Berkeley told Space.com. "It's fun to have been able to find the first one." 

The supernova, which was discovered on Nov. 11, 2014, is located about 9.3 billion light-years away from Earth, near the edge of the observable universe. The researchers have named the distant supernova SN Refsdal in honor of the late Norwegian astrophysicist Sjur Refsdal, a pioneer of gravitational lensing studies. Due to gravitational lensing, "the supernova appears 20 times brighter than its normal brightness," study co-author Jens Hjorth, head of the Dark Cosmology Centre at the Niels Bohr Institute at the University of Copenhagen, said in a statement.
The lensing galaxy, which is about 5 billion light-years from Earth, is part of a large cluster of galaxies known MACS J1149.6+2223. In 2009, astronomers discovered that this cluster was the source of the largest known image of a spiral galaxy ever seen through a gravitational lens.

The four images of the supernova each appeared separately over the course of a few weeks. This is because light can take various paths around and through a gravitational lens, arriving at Earth at different times.

Using gravity as a lens

Gravity is created when matter warps the fabric of reality. The greater the mass of an object, the more space-time curves around that object and the stronger its gravitational pull, the discovery enshrined in Einstein's theory of general relativity, which celebrates its centennial this year.

As a result, gravity can also bend light like a lens, meaning objects see n behind powerful gravitational fields, such as those of massive galaxies, are magnified. Gravitational lensing was first discovered in 1979, and today gravitational lenses can help astronomers see features otherwise too distant and faint to detect with even the largest telescopes.

"These gravitational lenses are like a natural magnifying glass. It's like having a much bigger telescope," Kelly said in a statement. "We can get magnifications of up to 100 times by looking through these galaxy clusters."

When light is far from a gravitationally lensing mass, or if the gravitationally lensing mass is not especially large, only "weak lensing" occurs, barely distorting the light. However, when the light comes from almost exactly behind the gravitationally lensing mass, "strong lensing" can happen. 

When a strongly lensed object occupies a large patch of space — for instance, if it's a galaxy — it can get smeared into an "Einstein ring" surrounding a gravitationally lensing mass. However, strong lensing of small, pointlike items — for instance, super-bright objects known as quasars — often produces multiple images surrounding the gravitationally lensing mass, resulting in a so-called "Einstein cross."

The observations of SN Refsdal mark the first time astronomers on Earth have witnessed strong lensing of a  supernova, with four images of an exploding star arrayed as an Einstein cross.

An expanding universe

These new findings could help scientists measure the accelerating rate at which the universe is expanding, researchers say.

A computer model of the lensing cluster suggests the scientists missed chances to see the lensed supernova 50 and 10 years ago. However, the model also suggests more images of the explosion will repeat again within the next 10 years.

The timing of when all these images of the supernova arrive depends on the gravitational pull of the matter generating the gravitational lens. So, by measuring those times, the researchers hope to map how visible normal matter and invisible dark matter is distributed in the lensing galaxy.

Dark matter is currently one of the greatest mysteries in science, a poorly understood substance thought to make up five-sixths of all matter in the universe. A better understanding of how dark matter is behaving in this gravitationally lensing cluster might help shed light on the material's nature, Kelly said.

Analyzing when the images arrive could also help scientists pinpoint the rate at which the universe is expanding. Although there are already several ways to measure the cosmic expansion rate, "there has been a lot of heated debate between different methods, so it'd be interesting to see how this new technique might affect the area," Kelly said. "It's always nice to have completely independent measurements of the same quantity."

The scientists detailed their findings in the March 6 issue of the journal Science.

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Mars Had an Ocean, Scientists Say, Pointing to a Treasure Trove of New Data

March 5, 2015 / / 0 Comments





Excerpt from nytimes.com

After six years of planetary observations, scientists at NASA say they have found convincing new evidence that ancient Mars had an ocean.

It was probably the size of the Arctic Ocean, larger than previously estimated, the researchers reported on Thursday. The body of water spread across the low-lying plain of the planet’s northern hemisphere for millions of years, they said.

If confirmed, the findings would add significantly to scientists’ understanding of the planet’s history and lend new weight to the view that ancient Mars had everything needed for life to emerge.
“The existence of a northern ocean has been debated for decades, but this is the first time we have such a strong collection of data from around the globe,” said Michael Mumma, principal investigator at NASA’s Goddard Center for Astrobiology and an author of the report, published in the journal Science. “Our results tell us there had to be a northern ocean.”
But other experts said the question was hardly resolved. The ocean remains “a hypothesis,” said Ashwin Vasavada, project scientist of the Curiosity rover mission at the Jet Propulsion Laboratory in Pasadena, Calif.

Dr. Mumma and Geronimo Villanueva, a planetary scientist at NASA, measured two slightly different forms of water in Mars’ atmosphere. One is the familiar H2O, which consists of two hydrogen atoms and one oxygen atom.

The other is a slightly “heavier” version of water, HDO, in which the nucleus of one hydrogen atom contains a neutron. The atom is called deuterium.

The two forms exist in predictable ratios on Earth, and both have been found in meteorites from Mars. A high level of heavier water today would indicate that there was once a lot more of the “lighter” water, somehow lost as the planet changed.

The scientists found eight times as much deuterium in the Martian atmosphere than is found in water on Earth. Dr. Villanueva said the findings “provide a solid estimate of how much water Mars once had by determining how much water was lost to space.”

He said the measurements pointed to an ancient Mars that had enough water to cover the planet to a depth of at least 137 meters, or about 450 feet. Except for assessments based on the size of the northern basin, this is the highest estimate of the amount of water on early Mars that scientists have ever made.

The water on Mars mostly would have pooled in the northern hemisphere, which lies one to three kilometers — 0.6 to 1.8 miles — below the bedrock surface of the south, the scientists said.
At one time, the researchers estimated, a northern ocean would have covered about 19 percent of the Martian surface. In comparison, the Atlantic Ocean covers about 17 percent of Earth’s surface.

The new findings come at a time when the possibility of a northern ocean on Mars has gained renewed attention.

The Curiosity rover measured lighter and heavier water molecules in the Gale Crater, and the data also indicated that Mars once had substantial amounts of water, although not as much as Dr. Mumma and Dr. Villanueva suggest.

“The more water was present — and especially if it was a large body of water that lasted for a longer period of time — the better the chances are for life to emerge and to be sustained,” said Paul Mahaffy, chief of the atmospheric experiments laboratory at the Goddard Space Flight Center.

Just last month, the science team running the Curiosity rover held its first formal discussion about the possibility of such an ocean and what it would have meant for the rest of Mars.

Scientists generally agree that lakes must have existed for millions of years in Gale Crater and elsewhere. But it is not clear how they were sustained and replenished.

“For open lakes to remain relatively stable for millions of years — it’s hard to figure how to do that without an ocean,” Dr. Vasavada said. “Unless there was a large body of water supplying humidity to the planet, the water in an open lake would quickly evaporate and be carried to the polar caps or frozen out.”

Yet climate modelers have had difficulty understanding how Mars could have been warm enough in its early days to keep water from freezing. Greenhouse gases could have made the planet much warmer at some point, but byproducts of those gases have yet to be found on the surface.

James Head, a professor of geological sciences at Brown University, said in an email that the new paper had “profound implications for the total volume of water” on ancient Mars.

But, he added, “climate models have great difficulty in reconstructing an early Mars with temperatures high enough to permit surface melting and liquid water.”

Also missing are clear signs of the topographic and geological features associated with large bodies of water on Earth, such as sea cliffs and shorelines.

Based on low-resolution images sent back by the Viking landers, the geologist Timothy Parker and his colleagues at the NASA Jet Propulsion Lab reported in 1989 the discovery of ancient shorelines. But later high-resolution images undermined their conclusions.

Still, Dr. Parker and his colleagues have kept looking for — and finding, they say — some visible signs of a northern ocean. The new data “certainly encourages me to do more,” he said in an interview.

Other researchers have also been looking for signs of an ancient ocean.

In 2013, Roman DiBiase, then a postdoctoral student at the California Institute of Technology, and Michael Lamb, an assistant professor of geology there, identified what might have been a system of channels on Mars that originated in the southern hemisphere and emptied steeply into the northern basin — perhaps, they said, water flowing through a delta to an ocean.

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Scientists Believe Oxygen Free Methane Based Aliens Might Exist on Icy Saturn Moon Titan

February 28, 2015 / / 0 Comments





Excerpt from viralglobalnews.com

A group of scientists at Cornell University believe that Titan, one of Saturn’s moons, may be a haven of life. However, it would not be in the form that human beings know. Methane based life forms might live on Titan, the scientists have said, after they created a model of an oxygen free life form which would be able to thrive in the icy, unforgiving conditions that Saturn’s moon offers.
They studied the various forms of cell membranes that exist on Earth, which are made up of lipid bi-layer structures. The Cornell scientists said such membranes would not be able to exist in environments where liquid water could not be present, according to Design and Trend.
Titan has plenty of lakes filled with methane, so that means it might not be habitable in the way that scientists had formerly described habitability. However, Dr. James Stevenson and his team thinks that contrarily structured membranes could offer the foundation for life to exist on Saturn’s moon. The model they created used organic nitrogen mixtures, so that the new structure could easily function on Titan in the richness of the methane that exists in liquid form there.

 Titan

Dr. Stevenson said it was Isaac Asimov, the celebrated sci-fi writer, who first gave the rudimentary inspiration for the idea in the paper he penned, which was called the Not as We Know It essay. It was written about non-water-based life forms. Because Saturn’s moon is the only known celestial form in the solar system to have naturally occurring fluids on its surface, except for the Earth, the group of scientists believe it to be a possible perfect foundation for life forms to develop.
Dr. Paulette Clancy, who has helped lead the group, constructed an “azotosome.” It is comparable in name origin to liposome which comes from the Greek words lipos and soma. An azotosome comes from the French word for nitrogen. Therefore, the word is describing a nitrogen body.
Instead of trying to find alien life within the area that surrounds the Sun where water exists in liquid form, the group decided to try and imagine a new kind of cell, grounded on methane instead of water. Clancy and the team were dumbfounded to find that this new projected model presented an alike stability to the cell membranes already here on Earth.
Dr. Clancy seemed very anxious to carry on the group’s work and find out how such compounds would truly work in the methane atmosphere. Dr. Jonathan Lunine, who is a top expert in Titan and also one of the co-authors of the study, thinks that it might be possible in the future to in fact test these theories by actually examing organic material from Saturn’s moon. In the years to come, Dr. Lunine stated that probes might be sent to Titan to gather the needed material by floating down on the methane seas of the moon of Saturn.
The group discovered a compound they named acrylonitrile azotosome, which appeared to show good stability. It had a strong barricade to decomposition, and a suppleness that was similar to phospholipid membranes that exist on Earth. Acrylonitrile is a poisonous, colorless, liquid organic compound that is used in the production of acrylic fibers and thermoplastics and it is present in Titan’s atmosphere as well.
They have written up about their discovery and what they believe to be possible. The scientists’ paper was printed up in the journal Science Advances on Friday.

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A Major Victory for the Open Web

February 27, 2015 / / 0 Comments

Excerpt from blog.mozilla.org
We just accomplished something very important together. Today, the U.S. Federal Communications Commission voted for strong net neutrality protections. This happened because millions of people — including many hundreds of thousands in Mozilla’s community — joined together as citizens of the Web to demand those strong protections.


This is an important victory for the world’s largest public resource, the open Web. Net neutrality is a key aspect of enabling innovation from everywhere, and especially from new players and unexpected places. Net neutrality allows citizens and consumers to access new innovations and judge the merit for themselves. It allows individual citizens to make decisions, without gate-keepers who decide which possibilities can become real. Today’s net neutrality rules help us protect this open and innovative potential of the Internet.

Mozilla builds our products to put this openness and opportunity into the hands of individuals. We are organized as a non-profit so that the assets we create benefit everyone. Our products go hand-in-hand with net neutrality; they need net neutrality to bring the full potential of the Internet to all of us.

Today’s net neutrality rules are an important step in protecting opportunity for all. This victory was not inevitable. It occurred because so many people took action, so many people put their voice into the process. To each of you we say “Thank you.” Thank you for taking the time to understand the issue, for recognizing it’s important, and for taking action. Thank you for helping us build openness and opportunity into the very fabric of the Internet.

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‘Firefly’ Starship to Blaze a Trail to Alpha Centauri?

February 21, 2015 / / 0 Comments

The Icarus Interstellar 'Firefly' starship concept could use novel nuclear fusion techniques to power its way to Alpha Centauri within 100 years.Adrian MannExcerpt from news.discovery.com As part of Icarus Interstellar's continuing series ...

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Cluster Filled with Dark Matter May House ‘Failed Galaxies’

February 21, 2015 / / 0 Comments

The Coma Cluster


Excerpt space.com

 A strange set of 48 galaxies appears to be rich in dark matter and lacking in stars, suggesting that they may be so-called "failed" galaxies, a new study reports.

The galaxies in question are part of the Coma Cluster, which lies 300 million light-years from Earth and packs several thousand galaxies into a space just 20 million light-years across. To study them, Pieter van Dokkum of Yale University and his colleagues used the Dragonfly Telephoto Array in New Mexico.

The array's eight connected Canon telephoto lenses allow the researchers to search for extremely faint objects that traditional telescope surveys miss. Often, such as when the researchers used the array to search for the faint glow that dark matter might create, the hunt comes up empty. 


But when van Dokkum and his colleagues looked toward the Coma Cluster, they found a pleasant surprise.

"We noticed all these faint little smudges in the images from the Dragonfly telescope," van Dokkum told Space.com.

The mysterious blobs nagged at van Dokkum, compelling him to look into the objects further. Fortuitously, NASA's Hubble Space Telescope had recently captured one of these objects with its sharp eye. 

"It turned out that they're these fuzzy blobs that look somewhat like dwarf spheroidal galaxies around our own Milky Way," van Dokkum said. "So they looked familiar in some sense … except that if they are at the distance of the Coma Cluster, they must be really huge."

And with very few stars to account for the mass in these galaxies, they must contain huge amounts of dark matter, the researchers said. In fact, to stay intact, the 48 galaxies must contain 98 percent dark matter and just 2 percent "normal" matter that we can see. The fraction of dark matter in the universe as a whole is thought to be around 83 percent. 

But before making this claim, the team had to verify that these blobs really are as distant as the Coma Cluster. (In fact, the team initially thought the galaxies were much closer.). But even in the Hubble image the stars were not resolved. If Hubble — one of the most powerful telescopes in existence — can't resolve the stars, those pinpricks of light must be pretty far away, study team members reasoned. 

Now, van Dokkum and his colleagues have definitive evidence: They've determined the exact distance to one of the galaxies. The team used the Keck Telescope in Hawaii to look at one of the objects for two hours. This gave them a hazy spectrum, from which they were able to tease out the galaxy's recessional velocity — that is, how fast it is moving away from Earth.

That measure traces back to the Hubble Telescope's namesake. In 1929, American astronomer Edwin Hubble discovered one of the simplest and most surprising relationships in astronomy: The more distant a galaxy, the faster it moves away from the Milky Way.

Today, astronomers use the relationship to measure a galaxy's recessional velocity and thus calculate the galaxy's distance. In this case, the small fuzzy blob observed with Keck was moving away from Earth at 15.7 million mph (25.3 million km/h). That places it at 300 million light-years away from Earth, the distance of the Coma Cluster.

So the verdict is officially in: These galaxies must be associated with the Coma Cluster and therefore must be extremely massive.
"It looks like the universe is able to make unexpected galaxies," van Dokkum said, adding that there is an amazing diversity of massive galaxies.

But the clusters still present a mystery: The team doesn't know why they have so much dark matter and so few stars.

Though they look serene and silent from our vantage on Earth, stars are actually roiling balls of violent plasma. Test your stellar smarts with this quiz.
One possibility is that these are "failed" galaxies. A galaxy's first supernova explosions will drive away huge amounts of gas. 

Normally, the galaxy has such a strong gravitational pull that most of the expelled gas falls back onto the galaxy and forms the next generations of stars. But maybe the strong gravitational pull of the other galaxies in the Coma Cluster interfered with this process, pulling the gas away.

"If that happened, they had no more fuel for star formation and they were sort of stillborn galaxies where they started to get going but then failed to really build up a lot of stars," said van Dokkum, adding that this is the most likely scenario. 

Another possibility is that these galaxies are in the process of being ripped apart. But astronomers expect that if this were the case, the galaxies would be distorted and streams of stars would be flowing away from them. Because these effects don't appear, this scenario is very unlikely.

The next step is to try to measure the individual motions of stars within the galaxies. If the team knew those stars' speeds, it could calculate the galaxies' exact mass, and therefore the amount of dark matter they contain. If the stars move faster, the galaxy is more massive. And if they move slower, the galaxy is less massive. 
However, this would require a better spectrum than the one the team has right now.

"But it's not outside the realm of what's possible," van Dokkum assured. "It's just very hard."

The original study has been published in Astrophysical Journal Letters. You can read it for free on the preprint site arXiv.org.

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NASA and ESA telescopes trace ultra-strong winds blowing from black holes

February 21, 2015 / / 0 Comments


 



Excerpt from thespacereporter.com

According to a NASA statement, telescopes have revealed for the first time that powerful winds emanate from black holes in all directions. These winds are so tremendous that they can actually work to hamper the formation of new stars in the host galaxy.
The two telescopes that were employed by the agency, NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR) and ESA’s XMM-Newton, focused on PDS 456, a quasar, an extremely bright type of black hole, over 2 billion light-years away. The results were then analyzed by a team led by Emanuele Nardini of Keele University in the UK.
The two telescopes studied the quasar PDS 456 at five different times throughout 2013 and 2014. By combining low-energy X-ray observations from XMM-Newton with high-energy X-ray observations from NuSTAR, Nardini and team were able to trace iron dispersed by the quasar’s winds. These data demonstrated that the winds blow outwards from the black hole in a spherical front.
Having ascertained the structure of the quasar winds, the team was then able to calculate the strength of the winds. So strong are the quasar winds that they push huge quantities of matter before them, dispersing it outwards through the host galaxy and preventing it from eventually coalescing to generate new stars. In an earlier period of the universe’s history, about 10 billion years ago, supermassive black holes were more abundant and their terrible winds probably had a hand in shaping the current shapes of galaxies.
“For an astronomer, studying PDS 456 is like a paleontologist being given a living dinosaur to study,” said co-author Daniel Stern of NASA’s Jet Propulsion Laboratory. “We are able to investigate the physics of these important systems with a level of detail not possible for those found at more typical distances, during the ‘Age of Quasars.’”
The new findings have been published in the journal Science.

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