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aamukherjee A Slice of Entropie -
alchymista Alchymista -
crownedrose Fading Like A Dead Star -
expose-the-light Quarks to Quasars -
ikenbot CWL -
abluegirl A Blue Girl -
perscientiamlibertas A Matter of the Most Pleasant Fraternal Confidence
A huge amount of radiation is generated by the million degree accretion disk of trapped gas whirling around the 4 billion solar mass black hole at our galaxy’s heart.
Makoto Inoue of the Institute of Astronomy and Astrophysics in Taipei, and Hiromitsu Yokoo of Chiba University are proposing that advanced civilizations might pool their resources to construct a ring of “power stations” at the galaxy’s core. They would orbit the central black hole just beyond its solar system-sized accretion disk.
Some fraction of the radiation seething from the disk would be reflected and focused onto the power plants. Each power plant would transmit collected energy as a collimated microwave beam from a 100-mile diameter antenna.
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Monster Black Holes Are Most Massive Ever Discovered
Scientists have discovered the largest black holes yet, and they’re far bigger than researchers expected based on the galaxies in which they were found. The discovery suggests we have much to learn about how monster black holes grow, scientists said.
All large galaxies are thought to harbor super-massive black holes at their hearts that contain millions to billions of times the mass of our sun. Until now, the largest black hole known was a mammoth dwelling in the giant elliptical galaxy Messier 87. This black hole has a mass 6.3 billion times that of the sun.
Now research suggests black holes in two nearby galaxies are even bigger. The scientists used the Gemini and Keck observatories in Hawaii and the McDonald Observatory in Texas to monitor the velocities of stars orbiting around the centers of a pair of galaxies. These velocities reveal the strength of the gravitational pull on those stars, which in turn is linked with the masses of the black holes lurking there.
The new findings suggest that one galaxy, known as NGC 3842, the brightest galaxy in the Leo cluster of galaxies nearly 320 million light years distant, has a central black hole 9.7 billion solar masses large. The other, named NGC 4889, the brightest galaxy in the Coma cluster more than 335 million light years away, has a black hole of comparable or larger mass. Both encompass regions or “event horizons” about five times the distance from the sun to Pluto.
“For comparison, these black holes are 2,500 times as massive as the black hole at the center of the Milky Way galaxy, whose event horizon is one-fifth the orbit of Mercury,” said study lead author Nicholas McConnell at the University of California, Berkeley. Astronomers had suspected that black holes more than 10 billion solar masses large exist, based on light from quasars, cosmic objects from the early universe that are no more than a light year or two across but are thousands of times brighter than our entire galaxy.
The light of quasars is thought to come from matter driven to incandescent brightness as it spirals at high speeds into supermassive black holes. This is the first time scientists have detected black holes approaching such theorized giants in size.
“These two new supermassive black holes are similar in mass to young quasars, and may be the missing link between quasars and the supermassive black holes we see today,” said study co-author Chung-Pei Ma, an astrophysicist at the University of California, Berkeley.
What Will First Photos of Black Holes Look Like?
“A giant black hole is thought to lurk at the center of the Milky Way, but it has never been directly seen. Now astronomers have predicted what the first pictures of this black hole will look like when taken with technology soon to be available.
In particular, researchers have found that pictures of a black hole ― or, more precisely, the boundaries around them ― will take a crescent form, rather than the blobby shape that is often predicted.
By modeling what these pictures will look like, scientists say they are preparing to interpret the photos that will become available from telescopes currently under construction.
No one has been able to image a black hole,” said University of California, Berkeley student Ayman Bin Kamruddin, who presented a poster on the research last week in Long Beach, Calif., at the 221st meeting of the American Astronomical Society. “So far it’s been impossible because they’re too small in the sky. Right now we’re just getting some details about the structure, but we don’t have an image yet.”
Black holes themselves are invisible, of course, as not even light can escape their gravitational clutches. However, the boundary of a black hole — the point of no return called the event horizon — should be visible from the radiation emitted by matter falling into the black hole. “
Black holes come in a variety of sizes, ranging from 10 times the mass of the sun to a billion times as massive. But new research shows that black holes of completely different masses, ages and locations can produce jets of ionized gas that behave similarly.
Image: This illustration shows a black hole emitting jets of fast-moving plasma above and below it, as matter swirls around in an orbiting disk. Credit: NASA’s Goddard Space Flight Center
“As scientists, we are always seeking universal principles,” Rodrigo Nemmen, of NASA’s Goddard Space Flight Center in Greenbelt, Md., told SPACE.com.
Nemmen and his colleagues studied a wide variety of black holes in an attempt to compare how efficiently their jets emitted light. “I was very surprised,” Nemmen said of the results.
Discovering similarities between ancient supermassive black holes in the center of distant galaxies and baby black holes born as stars collapse should help scientists gain a firmer understanding of these jets.
Cosmic accelerators
Black holes are well known for their ability to pull matter into them. But not all material near a black hole finds itself lost. Some bits of matter just outside the point of no return (called the event horizon) are accelerated away at near-light speeds, creating jets of particles shooting out above and below the black holes.
“I like to call black holes ‘cosmic LHCs,’ or very powerful particle accelerators,” Nemmen said, referring to the Large Hadron Collider, an underground machine in Switzerland that speeds protons to 99.9999991 percent the speed of light.
When matter is spun away from a black hole in the form of a jet, most of its energy goes into its motion, but some of it is changed into light in the form of gamma-rays. Nemmen and his team studied findings on 293 previously observed black holes and calculated how efficiently the jets converted energy to light. They found that the rate scaled across the range of black holes.
“This was one of the surprises of this work, that this efficiency of conversion of the energy into light is essentially the same for black holes with very different masses, very different ages and completely different environments,” Nemmen said.
Black holes are powerful beasts, interesting in and of themselves. But by accelerating ionized gas, they also have the potential to change their environment. Heating up space, they could affect the production of new stars, thereby influencing the galaxy they live in.
“These jets might be powerful agents of creating changes in the host galaxy,” Nemmen said.
Scientists still don’t have a strong understanding of how these violent particle outflows form. But the fact that the energy efficiency of the jets scales across black holes may help theorists better understand how something that pulls in most particles could shoot away others, and how the outflow of energy may affect surrounding space.
The findings were published online today (Dec. 13) in the journal Science.
“It’s not an exaggeration to say that if black holes did not exist, we wouldn’t be here.” — Phil Plait
Jets powered by the gravitational energy of a super massive black hole in the core of the elliptical galaxy Hercules A are seen in this composite image from the Hubble Space Telescope’s Wide Field Camera 3 and the recently upgraded Karl G. Jansky Very Large Array (VLA) radio telescope in New Mexico. Hercules A is some two billion light-years away and is roughly 1,000 times more massive than the Milky Way; the black hole at its center is 2.5 billion times the mass of our Sun. (Photo: NASA / ESA via Rex Features/ The Telegraph)
Whoa.
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Monster Black Hole Is Biggest Ever Found
Astronomers have discovered what may be the most massive black hole ever known in a small galaxy about 250 million light-years from Earth, scientists say.
Image: This image shows the disk galaxy NGC 1277, as seen by the Hubble Space Telescope. The small, flattened galaxy has one of the biggest central super-massive black holes ever found in its center, the equivalent of 17 billion suns.<.em> Credit: NASA / ESA / Andrew C. Fabian / Remco C. E. van den Bosch (MPIA)
The supermassive black hole has a mass equivalent to 17 billion suns and is located inside the galaxy NGC 1277 in the constellation Perseus. It makes up about 14 percent of its host galaxy’s mass, compared with the 0.1 percent a normal black hole would represent, scientists said.
“This is a really oddball galaxy,” said study team member Karl Gebhardt of the University of Texas at Austin in a statement. “It’s almost all black hole. This could be the first object in a new class of galaxy-black hole systems.”
The giant black hole is about 11 times as wide as the orbit of Neptune around our sun, researchers said. The mass is so far above normal that the scientists took a year to double-check and submit their research paper for publication, according to the study’s lead author, Remco van den Bosch.
“The first time I calculated it, I thought I must have done something wrong. We tried it again with the same instrument, then a different instrument,” van den Bosch, an astronomer at Germany’s Max Planck Institute for Astronomy, told SPACE.com. “Then I thought, ‘Maybe something else is happening.’”
Biggest Black Hole Blast Ever Could Solve Cosmological Mystery
Astronomers have seen a distant galaxy that blasts away material with two trillion times the energy the sun emits — the biggest such eruption ever seen. That ejection of matter could answer an important question about the universe: why are the black holes in the centers of galaxies so light?
Image: Artist’s impression of the huge outflow ejected from the quasar SDSS J1106+1939 Credit: ESO/L. Calçada
Computer models of the early universe usually produce a virtual cosmos that looks like ours except for one thing. The ratio of the mass of black holes in galaxy centers to the rest of the matter in galaxies is larger in the simulations than in the real universe.
Scientists think somehow galaxies are ridding themselves of much of the mass that would have ended up falling into their central black holes. However, until now researchers have been at a lack for an explanation of how this might happen.
To expel matter from galaxies takes energy. “We needed some input of energy from supermassive black holes,” Nahum Arav, an astrophysicist at Virginia Tech.
Supermassive black holes are obvious candidates, because they are the most energetic objects known. Some galaxies containing active black holes, called quasars, shine more brightly than anything else in the universe. “Our simulations showed that if we allowed the quasar to release a lot of mechanical energy, then the masses of galaxies would match observations,” Arav said.
Arav led a team that observed a quasar, called SDSS J1106+1939, which dates back to when the universe was only 3 billion years old (it is now about 13.7 billion years of age). Most quasars are millions or even billions of light-years distant, which means we see them as they were long ago. As such, they offer a unique window back in time, to when galaxies were young.
Distant Black Holes Map Universe’s Dark Energy History
Extremely bright black holes gobbling up matter in the distant universe have provided a window back in time for astronomers to study dark energy more than 10 billion years ago.
Image: Light from distant quasars (red dots at left) is partially absorbed as it passes through clouds of hydrogen gas. Astronomers working on the BOSS survey used this effect to study the history of dark energy in the universe’s ancient past. Credit: Zosia Rostomian, Lawrence Berkeley National Laboratory; Nic Ross, BOSS Lyman-alpha team, Berkeley Lab; and Springel et al, Virgo Consortium and Max Planck Institute for Astrophysics
Dark energy is the mysterious force thought to be pulling everything in the universe apart, causing space-time to expand and galaxies to move farther and farther away from each other, all at an accelerating clip.
Dark energy, whatever it is, currently appears to be beating out the attractive of force of gravity that works to pull galaxies and everything in the universe closer together. However, that wasn’t always the case. When the universe was young, astronomers think dark energy’s impact was small, and gravity won out.
To confirm this idea and learn about when gravity lost the fight to dark energy, astronomers must look back in time. They do that by studying extremely far objects whose light has taken billions of years to reach us on Earth, thus presenting a picture of them as they were long ago.
Now, researchers report observations of the early universe from the Baryon Oscillation Spectroscopic Survey (BOSS), which studied thousands of distant objects called quasars to map out the universe up to 11.5 billion years ago. Quasars are active black holes that release copious amounts of light as they gorge on matter.
“No technique for dark energy research has been able to probe this ancient era before, a time when matter was still dense enough for gravity to slow the expansion of the universe, and the influence of dark energy hadn’t yet been felt,” BOSS principal investigator David Schlegel, an astrophysicist at the Lawrence Berkeley National Laboratory in California, said in a statement. “In our own time, expansion is accelerating because the universe is dominated by dark energy. How dark energy effected the transition from deceleration to acceleration is one of the most challenging questions in cosmology.”
“We are seeing back to the matter-dominated universe, when expansion was decelerating and dark energy was hard to see,” said Berkeley astrophysicist Martin White. “The transition from decelerating expansion to accelerating expansion was a sharp one, and now we live in a universe dominated by dark energy. The biggest puzzle in cosmology is, why now?”
Mouth of Giant Black Hole Measured for First Time
For the first time, scientists have peered to the edge of a colossal black hole and measured the point of no return for matter.
Image: This image from a simulation shows an energy jet launched from a spinning black hole surrounded by a disk of accreting material. The black hole is spinning at half the maximum rate, and its mass is that of the black hole at the center of the M87 elliptical galaxy. The central black hole ‘shadow’ due to extreme light bending is apparent in this simulation. Credit: Avery E. Broderick (University of Waterloo/Perimeter
A black hole has a boundary called an event horizon. Anything that falls within a black hole’s event horizon — be it stars, gas, or even light — can never escape.
“Once objects fall through the event horizon, they’re lost forever,” Shep Doeleman, assistant director of the MIT Haystack Observatory and research associate at the Smithsonian Astrophysical Observatory, said in a statement Thursday (Sept. 27). “It’s an exit door from our universe. You walk through that door, you’re not coming back.”
Although the event horizon is an imaginary line that’s impossible to observe, astronomers have imaged the region around a giant black hole at the center of a distant galaxy, and measured, for the first time, the closest stable orbit in which matter can circle the black hole. The findings were reported today in the journal Science.
The supermassive black hole in question lies at the center of the galaxy M87, which is about 50 million light-years from our own Milky Way. This behemoth black hole contains the mass of 6 billion suns.
Image: This views show the simulated event horizon-resolving images for the ultra-relativistic jet launched from the 7 billion solar-mass black hole at the center of the giant elliptical galaxy M87. Credit: Avery E. Broderick (University of Waterloo/Perimeter Institute)
Black Hole ‘Bonanza’: Millions Found by NASA Space Telescope
A jackpot of previously unknown black holes across the universe has been discovered by the infrared eyes of a prolific NASA sky-mapping telescope.
The cosmic find comes from data collected by NASA’s Wide-field Infrared Survey (WISE) telescope, which scanned the entire sky in infrared light from December 2009 to February 2011. The full catalog of observations by WISE during its mission was publicly released in March, and astronomers are still poring through this celestrial trove for discoveries.
“WISE has found a bonanza of black holes in the universe,” astronomer Daniel Stern of NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif., said during a news briefing today (Aug. 29). WISE turned up about three times as many black holes as have been found by comparable surveys in visible light, offering up a total of 2.5 million new sources across the sky.
Ingredients for Gigantic Black Holes Detected in Milky Way’s Core
Scientists investigated our galaxy’s central molecular zone, which contains the most massive, densest, and most turbulent molecular clouds in the Milky Way. These surround the heart of our galaxy, which is suspected to be home to a supermassive black hole about 4 million times the mass of the sun.
Image: An artist’s illustration of a newfound large star cluster near the center of the Milky Way that may be a breeding ground for intermediate black holes. Credit: Keio University
The central molecular zones of galaxies crowd lots of gas close together, making them good places for stars to form. To learn more about these lively regions, scientists used radio telescopes to compile detailed maps of the temperature and density of clouds at the Milky Way’s heart.
Now scientists have discovered four giant clumps of gas that appear to be the kinds of seeds intermediate-mass black holes arise from. These black holes hundreds to thousands of times the mass of the sun that are thought to in turn serve as the building blocks for the supermassive black holes found in the centers of galaxies.
