Spinning Black Holes

Results from NASA's Chandra X-ray Observatory, combined with new theoretical calculations, provide one of the best pieces of evidence yet that many supermassive black holes are spinning extremely rapidly.

The images below show 4 out of the 9 large galaxies included in the Chandra study, each containing a supermassive black hole in its center.



The Chandra images show pairs of huge bubbles, or cavities, in the hot gaseous atmospheres of the galaxies, created in each case by jets produced by a central supermassive black hole. Studying these cavities allows the power output of the jets to be calculated. This sets constraints on the spin of the black holes when combined with theoretical models.

The Chandra images were also used to estimate how much fuel is available for each supermassive black hole, using a simple model for the way matter falls towards such an object. The artist's impression on the right side of the main graphic shows gas within a "sphere of influence" falling straight inwards towards a black hole before joining a rapidly spinning disk of matter near the center.

Most of the material in this disk is swallowed by the black hole, but some of it is swept outwards in jets (coloured blue) by quickly spinning magnetic fields close to the black hole.
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Death Star Galaxy

Credit: NASA, ESA, and D. Evans (Harvard-Smithsonian Center for Astrophysics)

A powerful jet from a supermassive black hole is blasting a nearby galaxy, according to new data from NASA observatories. This never-before witnessed galactic violence may have a profound effect on planets in the jet's path and trigger a burst of star formation in its destructive wake.

Known as 3C 321, the system contains two galaxies in orbit around each other. Data from NASA's Chandra X-ray Observatory show both galaxies contain supermassive black holes at their centers, but the larger galaxy has a jet emanating from the vicinity of its black hole. The smaller galaxy apparently has swung into the path of this jet.

This "death star galaxy" was discovered through the combined efforts of both space and ground-based telescopes. NASA's Chandra X-ray Observatory, Hubble Space Telescope, and Spitzer Space Telescope were part of the effort. The Very Large Array (VLA) in Socorro, N.M., and the Multi-Element Radio Linked Interferometer Network (MERLIN) telescopes in the United Kingdom also were needed for the finding.

Jets from supermassive black holes produce high amounts of radiation, especially high-energy X-rays and gamma-rays, which can be lethal in large quantities. The combined effects of this radiation and particles traveling at almost the speed of light could severely damage the atmospheres of planets lying in the path of the jet. For example, protective layers of ozone in the upper atmosphere of planets could be destroyed.

Jets produced by supermassive black holes transport enormous amounts of energy far from the black holes and enable them to affect matter on scales vastly larger than the size of the black hole. Learning more about jets is a key goal for astrophysical research.

The effect of the jet on the companion galaxy is likely to be substantial, because the galaxies in 3C 321 are extremely close at a distance of only about 20,000 light-years apart, approximately the same distance as Earth is from the center of the Milky Way galaxy.

A bright spot in the VLA and MERLIN images shows where the jet has struck the side of the galaxy, dissipating some of the jet's energy. The collision disrupted and deflected the jet.

Another unique aspect of the discovery in 3C 321 is how relatively short-lived this event is on a cosmic time scale. Features seen in the VLA and Chandra images indicate that the jet began impacting the galaxy about one million years ago, a small fraction of the system's lifetime. This means that such an alignment is quite rare in the nearby universe, making 3C 321 an important opportunity to study such a phenomenon.

It is possible the event is not all bad news for the galaxy being struck by the jet. The massive influx of energy and radiation from the jet could induce the formation of large numbers of stars and planets after its initial wake of destruction is complete.

For more images and information about 3C 321, visit:
http://chandra.harvard.edu
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Powerful Cosmic Winds

Black Holes Launch Powerful Cosmic Winds
Black holes often are thought of as just endless pits in space and time that destroy everything they pull toward them. But new findings confirm the reverse is true, too: Black holes can drive extraordinarily powerful winds that push out and force star formation and shape the fate of a galaxy.

Supermassive black holes are suspected to lurk in the hearts of many - if not all - large galaxies. These holes drag gas inward, which accrues in rapidly spinning, glowing disks.

Astronomers have long thought that such "accretion disks" give off mighty winds that shape the host galaxies, profoundly influencing how they grow.

"In the early universe, galaxies formed from clumps of gas coagulating from mutual gravitational attraction. If unhindered, they would have formed rather bigger structures than what we see today," said astrophysicist Andrew Robinson at the Rochester Institute of Technology in New York. "But if we take into account these winds blowing away surrounding gas, that could help explain the galaxy sizes we see."

Until now, scientists had only theorized that accretion disks launched these winds. No one had actually seen this happen. These accretion disks are comparable in size to our solar system - big for us - but on the scale of galaxies they're really tiny, and far away to boot, making it virtually impossible to distinguish any details such as winds.

To attempt to observe the winds, Robinson and his colleagues investigated a galaxy roughly 3 billion light years from Earth using the William Herschel Telescope on the Canary Islands off the coast of Africa. At the core of that galaxy lies a quasar, an extremely powerful source of radiation as bright as up to 1 trillion suns that originates from the superheated gas of a black hole's accretion disk.

The researchers discovered that light from the quasar was scattered by electrons in super-fast gas. The specific way in which this light was scattered suggests the gas was rotating at speeds similar to the accretion disk's rate of spin. In other words, they confirmed the accretion disk was launching wind.

The researchers will next try to find out if these disk winds are launched only when the black hole is growing rapidly, or just by quasars, which have the most massive black holes, or by all active galactic nuclei.

Findings detailed in the Nov. 1 issue of the journal Nature.
By Charles Q. Choi @ Live Science
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'Spitting' black holes may be key to cosmic mysteries from Space New Scientist
Supermassive Black Holes Produce Powerful Galaxy-shaping Winds - Science Daily
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Massive "Stellar" Black Hole

Credit: Aurore Simonnet/Sonoma State University/NASA

Astronomers have discovered a massive stellar black hole with an orbiting companion: a hot, highly evolved star. The new black hole, is the heftiest known black hole that orbits another star.

Formed in the death throes of massive stars, "stellar-mass" black holes are smaller than the monster black holes found in galactic cores. The previous record holder for largest stellar-mass black hole is a 16-solar-mass black hole in the galaxy M33, announced on October 17.

Located in the nearby dwarf galaxy IC 10, 1.8 million light-years from Earth in the constellation Cassiopeia. The star is ejecting gas in the form of a wind. Some of this material spirals toward the black hole, heats up, and gives off powerful X-rays before crossing the point of no return.

In November 2006, Andrea Prestwich of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., and her colleagues observed the dwarf galaxy with NASA’s Chandra X-ray Observatory.

The group discovered that the galaxy’s brightest X-ray source, IC 10 X-1, exhibits sharp changes in X-ray brightness. Such behavior suggests a star periodically passing in front of a companion black hole and blocking the X-rays, creating an eclipse. In late November, NASA’s Swift satellite confirmed the eclipses and revealed details about the star’s orbit.

The star in IC 10 X-1 appears to orbit in a plane that lies nearly edge-on to Earth’s line of sight, so a simple application of Kepler’s Laws show that the companion black hole has a mass of at least 24 Suns.

The black hole’s large mass is surprising because massive stars generate powerful winds that blow off many Suns worth of gas before the stars explode. Calculations suggest massive stars in our galaxy leave behind black holes no heavier than about 15 Suns.

The IC 10 X-1 black hole has gained mass since its birth by gobbling up gas from its companion star, but the rate is so slow that the black hole would have gained no more than 1 or 2 solar masses. "This black hole was born fat; it didn’t grow fat," says astrophysicist Richard Mushotzky of NASA Goddard Space Flight Center in Greenbelt, Md., who is not a member of the discovery team.

The progenitor star probably started its life with 60 or more solar masses. Like its host galaxy, it was probably deficient in elements heavier than hydrogen and helium. In massive, luminous stars with a high fraction of heavy elements, the extra electrons of elements such as carbon and oxygen “feel” the outward pressure of light and are more susceptible to being swept away in stellar winds.

But with its low fraction of heavy elements, the IC 10 X-1 progenitor shed comparatively little mass before it exploded, so it could leave behind a heavier black hole.

"Massive stars in our galaxy today are probably not producing very heavy stellar-mass black holes like this one," says coauthor Roy Kilgard of Wesleyan University in Middletown, Conn. "But there could be millions of heavy stellar-mass black holes lurking out there that were produced early in the Milky Way’s history, before it had a chance to build up heavy elements."

This release is being issued jointly with NASA
Massive Black Hole Smashes Record
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New Spin on how Stars Are Born from Live Science
Black Holes may harbour their own universes from Space New Scientist
White Dwarf "Sibbling Rivalry" explodes into Supernova CfA Press Release
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Distant Ancient Black Holes

Hundreds of "missing" black holes have been found lurking in dusty galaxies located 9 billion to 11 billion light-years away and existed at a time when the universe was between 2.5 and 4.5 billion years old.

"Active, supermassive black holes were everywhere in the early universe," said study team member Mark Dickinson of the National Optical Astronomy Observatory in Tuscon, Ariz. "We had seen the tip of the iceberg before in our search for these objects. Now, we can see the iceberg itself."

The finding, detailed in two studies published in the Nov. 10 issue of Astrophysical Journal, is the first direct evidence that most, if not all, massive galaxies in the distant universe spent their youths constructing supermassive black holes at their cores.

It could also help answer fundamental questions about how massive galaxies such as our Milky Way evolved.

Using NASA's Chandra X-ray and Spitzer Space Telescopes, the team detected unusually high levels of infrared light emitted by 200 galaxies in the distant universe. They think the infrared light was created by material falling into "quasars"-supermassive black holes surrounded by doughnut-shaped clouds of gas and dust-at the center of the galaxies.

The new quasar-containing galaxies are all about the same mass as our Milky Way, but are irregular in shape. For decades, scientists have predicted that a large population of quasars should be found at those distances but had only spotted a few of them.

The newfound quasars confirm what scientists have suspected for years now: that supermassive black holes play a major role in star formation in massive galaxies. The observations suggest massive galaxies steadily build up their stars and black holes simultaneously until they get too big and the black holes suppress star formation.

The new quasars also suggest that collisions between galaxies might not be as important for galaxy evolution as once thought. "Theorists thought mergers between galaxies were required to initiate this quasar activity, but now we see that quasars can be active in unharassed galaxies," said study team member David Alexander of Durham University in the UK.
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The improbable Universe by Pamela Star Stryder
Hubble Spies Shells of Sparkling Stars around Quasars
Texture discovered in Fabric of Space-Time from Scientific Blogging
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Extreme Stellar Black Hole

Credit: NASA/CXC/M. Weiss

An artist's representation of M33 X-7: a binary system in the nearby galaxy M33, containing a massive blue star feeding material to a black hole surrounded by a small accretion disk.

Stellar black holes form when stars with masses around 20 times that of the sun collapse under the weight of their own gravity at the ends of their lives. Most stellar black holes weigh in at around 10 solar masses when the smoke blows away.

The black hole in M33 X-7 located 2.7 million light-years from Earth, is also the most distant stellar black hole ever observed.

The findings, detailed in the Oct. 17 issue of the journal Nature, could help improve formation models of "binary" systems containing a black hole and a star. It could also help explain one of the brightest star explosions ever observed.

The blackhole orbits a companion star in the spiral galaxy Messier 33. The companion star of M33 X-7 passes directly in front of the black hole as seen from Earth once every three days, completely eclipsing its X-ray emissions. It is the only known binary system in which this occurs, and it was this unusual arrangement that allowed astronomers to calculate the pair's masses very precisely.

The tight orbits of the black hole and star suggests the system underwent a violent stage of star evolution called the common-envelope phase, in which a dying star swells so much it sucks the companion inside its gas envelope.

The result is either a merger between the two stars or the formation of a tight binary in which one star is stripped of its outer layers. The latter scenario may be what happens in the case of M33 X-7, and the stripped star explodes as a supernova before imploding to form a black hole.

However, something unusual must have happened to M33 X-7 during this phase to create such a massive black hole. The black hole must have lost a large amount of mass for the two objects to be so close, but on the other hand, it must have retained enough mass to form such a heavy black hole.

M33 X-7 might thus provide both the upper and lower limits on the amount of mass loss and orbital tightening that can occur in the common envelope.

While the estimated 16 solar masses of the black hole in M33 X-7 is hefty for a stellar black hole, it is miniscule compared with the black holes thought to lie in the heart of many large galaxies.

Such "supermassive" black holes have masses millions to billions times that of our sun, but they are thought to form by mechanisms different from the stellar variety.

M33 X-7: Heaviest Stellar Black Hole Discovered in Nearby Galaxy from Chandra
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The fantastic skies of Orphan Stars from NASA Science
Hubble finds Youthful-looking galaxy conceals ancient stars
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Feasting Blackhole bubbles

These NASA Hubble Space Telescope images of the galaxy's central region clearly show one of the bubbles rising from a dark band of dust. The other bubble, emanating from below the dust band, is barely visible, appearing as dim red blobs in the close-up picture of the galaxy's hub (the colourful picture at right).

The background image represents a wider view of the galaxy, with the central region defined by the white box.

These extremely hot bubbles are caused by the black hole's voracious eating habits. The eating machine is engorging itself with a banquet of material swirling around it in an accretion disk (the white region below the bright bubble). Some of this material is spewed from the disk in opposite directions. Acting like high-powered garden hoses, these twin jets of matter sweep out material in their paths.

The jets eventually slam into a wall of dense, slow-moving gas, which is traveling at less than 223,000 mph (360,000 kph). The collision produces the glowing material. The bubbles will continue to expand and will eventually dissipate.

Credits: NASA and Jeffrey Kenney (Yale University)
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Journey to the Black Hole from Space dotcom
Black Holes and Naked Singularities from Science Daily
Searching for Objects Even Stranger Than Black Holes from Universe Today
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Primordial Black Holes

Click on Image to Enlarge. Image Credit: Sprott Physics

Were vast numbers of black holes spawned during the universe's earliest moments?

So far, there is no hard evidence that such primordial black holes (PBHs) ever existed, but new observations just around the corner could change that.

There are a variety of ways that PBHs might have formed in the early universe. Concentrations of energy associated with exotic energy fields could collapse under their own gravity – according to Einstein's relativity, energy exerts gravity just as matter does – to make black holes. One such energy field is thought to be responsible for the rapid expansion (inflation) of the early universe.

A wide variety of masses for PBHs are possible, depending on the formation scenario. The least massive ones, with less than about the mass of a comet, or 1 trillion kilograms, would quickly evaporate through a quantum process known as Hawking radiation.

More massive PBHs, born with up to 100,000 times the mass of the Sun, could survive to put an imprint on the CMB cosmic microwave background, radiation emitted by warm matter roughly 400,000 years after the big bang.

Normally black holes would emit X-rays as they swallow matter from their surroundings, and these X-rays can escape the vicinity of the black holes to break apart, or ionise, hydrogen atoms. This would subtly affect how matter distributes itself into regions of high and low density - a distribution reflected in the CMB radiation.

This effect might explain a puzzling discrepancy between results of the Wilkinson Microwave Anisotropy Probe (WMAP), which measures the CMB, and studies of how galaxies are clustered.

The two disagree on a parameter called sigma8, which describes how matter clumped together in the early universe. But according to a recent study led by Massimo Ricotti of the University of Maryland in College Park, US, the two measurements agree if PBHs are included in the models.
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But Ricotti himself says it is too soon to claim there is evidence for primordial black holes. "It is still possible that refining the measurements will bring them into agreement without invoking these exotic objects," he says.

The study also suggests that the ionising effect of PBHs would have helped spark the formation of the first stars in the universe. The presence of free electrons helps pairs of hydrogen atoms to join together to form molecular hydrogen. "You form a lot of molecular hydrogen – about 10 to 100 times more than you would form if you didn't have primordial black holes," Ricotti said.

Molecular hydrogen helps to cool gas clouds by emitting radiation, allowing the clouds to contract enough to condense into stars. Ricotti says the James Webb Space Telescope, scheduled to launch in 2013, just may be able to detect this enhancement of star formation.

Perhaps most intriguingly, if primordial black holes survive in great enough numbers today, then clouds of them could account for some or even all of the mysterious dark matter in the universe.

The main problem with this possibility is that it is not clear whether the conditions needed to form PBHs in large numbers ever occurred in our universe.

In the formation scenario involving the inflation field, for example, the number of PBHs formed depends on unknowns such as the size of fluctuations in the inflation field. In some inflationary models, you can form a lot of PBHs; in others you form very few of them.

It is possible that unusually large amounts of ionisation in the early universe - possibly due to the X-rays emitted by PBHs - could be detected by Europe's Planck satellite, scheduled to launch in mid-2008, says WMAP team member Rachel Bean of Cornell University in Ithaca, New York, US.

If convincing evidence of primordial black holes ever emerges, it would give scientists an extremely important window into the universe at very early times.

The mass of the black holes would reveal the time at which they formed, since the different scenarios for their formation occur at different times and give different masses. If they formed at the end of inflation, then their existence would reveal important information about the murky physics of this period of rapid expansion.

"You could rule out models of inflation that don't produce these black holes," says physicist James Chisholm of Southern Utah University. "Someone would probably get a Nobel prize."
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Matter Surfs on Ripples of Space Time Around Black Hole
Adaptive optics leads the way to supermassive black holes
Supercomputer at RIT Takes on Black Holes and General Relativity
Herschel will have an unprecedented view of the cold universe. Herschel in Pics

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Super Massive Super Hot

NASA's Spitzer Space Telescope shows that supermassive black holes at the centers of elliptical galaxies keep the galactic "thermostat" so high gas cannot cool, stunting the birth of new stars.

Astronomers have detected dust grains mingling with blazing hot gas at temperatures of 10 million degrees Kelvin (10 million Celsius) or 17 million Fahrenheit, in an area surrounding the elliptical-shaped galaxy called NGC 5044.

Similar to raindrops forming in Earth's clouds, stars form when dense cosmic clouds of gas and dust condense. Scientists suspect that if the gas surrounding a galaxy never cools enough to condense, then new stars cannot form.

Galaxies in the universe come in many shapes and sizes. Spiral galaxies, like the Milky Way, are usually active in star formation.

By contrast, elliptical galaxies are stellar retirement communities because they are made up of older stars, and don't form many new stars. Many elliptical galaxies, like NGC 5044, are found at the centers of galaxy clusters that are filled with enormous amounts of hot gas. Why the gas doesn't cool and form new stars is a subject of intense debate among astronomers.
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Feedback heating

Observations with NASA's Hubble Space Telescope have shown small, massive clouds of dusty gas near the cores of many elliptical galaxies. Astronomers think these clouds may play a crucial role in feedback heating. They suspect this material probably gravitated toward the galaxy's center after being ejected by nearby dying stars, as part of their normal life cycle.

When some of this dusty gas approaches the host galaxy's central supermassive black hole, a large amount of energy is released -- enough to heat nearby gas to extremely high temperatures, making it buoyant. Like smoke carrying ashes away from a fire, scientists believe that this buoyant gas floats away from the galaxy's center carrying some dust with it. As plumes of this dusty smoke fill the galaxy's surrounding area, gas around the galaxy is also heated. Temi's team was the first to see this cosmic smoke with Spitzer's super-sensitive infrared eyes.

Whenever the central back hole takes another gulp of the dusty gas hovering around the galaxy's center, enough energy will be fed back to heat up more of the surrounding gas, and feedback heating will happen all over again, maintaining the temperature of the surrounding gas. Both the heating and buoyant removal of gas from the galaxy's center reduces the likelihood of star formation.

Astronomers have long hypothesized about feedback heating in the hot cluster gas surrounding elliptical galaxies, but Spitzer has given us the first piece of observational evidence that this might actually be occurring in elliptical galaxies across the universe.

Original Source: Do Supermassive Black Holes Stunt Stellar Birth in Galaxies?
by Linda Vu, Spitzer Science Center.

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New Type of Active Galaxy

Image credit: Aurore Simonnet, Sonoma State University.

This illustration shows the different features of an active galactic nucleus (AGN), and how our viewing angle determines what type of AGN we observe. The extreme luminosity of an AGN is powered by a supermassive black hole at the center. Some AGN have jets, while others do not.
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Japanese and NASA Satellites Unveil New Type of Active Galaxy

Active Galactic Nuclei AGN, the extraordinarily energetic cores of galaxies such as Quasars, Blazars, and Seyfert galaxies, powered by accreting supermassive black holes, are among the most luminous objects in our Universe, often pouring out the energy of billions of stars from a region no larger than our solar system.

By using Swift and Suzaku, a team of astronomers has discovered that a relatively common class of AGN escaped detection…until now. These objects are so heavily shrouded in gas and dust that virtually no light gets out.

Evidence for this new type of AGN began surfacing over the past two years. Using Swift’s Burst Alert Telescope (BAT), a team led by Tueller has found several hundred relatively nearby AGNs that were previously missed because their visible and ultraviolet light was smothered by gas and dust. The BAT was able to detect high-energy X-rays from these heavily blanketed AGNs because, unlike visible light, high-energy X-rays can punch through thick gas and dust.

According to popular models, AGNs are surrounded by a donut-shaped ring of material, which partially obscures our view of the black hole. Our viewing angle with respect to the donut determines what type of object we see.
But team member Richard Mushotzky, also at NASA Goddard, thinks these newly discovered AGN are completely surrounded by a shell of obscuring material.

Another possibility is that these AGN have little gas in their vicinity. In other AGN, the gas scatters light at other wavelengths, which makes the AGN visible even if they are shrouded in obscuring material. The results imply that there must be a large number of yet unrecognized obscured AGNs in the local universe.

In fact, these objects might comprise about 20 percent of point sources comprising the X-ray background, a glow of X-ray radiation that pervades our Universe. NASA’s Chandra X-ray Observatory has found that this background is actually produced by huge numbers of AGNs, but was unable to identify the nature of all the sources.

By missing this new class, previous AGN surveys were heavily biased, and thus gave an incomplete picture of how supermassive black holes and their host galaxies have evolved over cosmic history.

"We think these black holes have played a crucial role in controlling the formation of galaxies, and they control the flow of matter into clusters," says Tueller. "You can’t understand the universe without understanding giant black holes and what they’re doing."
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LISA - Beyond Einstein

The Beyond Einstein Program consists of five proposed missions:

two major observatories and three smaller probes. Technology development already is under way on the proposed observatories. The Laser Interferometer Space Antenna (LISA) would orbit the sun and measure gravitational waves in our galaxy and beyond.

Constellation-X would peer at matter falling into supermassive black holes. The planned probes would investigate the nature of dark energy, the physics of the Big Bang, and the distribution and types of black holes in the universe.

LISA is one project under study by the Einstein Probes Office. To study gravitational waves, LISA would “float” over them, much like a buoy on choppy seas. Image credit: NASA

Original Source: NASA will study Strange Cosmic Phenomena
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Einstein's Theory of General Relativity ~podcast~ from Universe Today
Spitzer Finds Water Vapour on Hot, Alien Planet press release 11/07/07
NASA's Stardust & Deep Impact to Observe More Comets And Extrasolar Planets
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Cosmic Blackholes

By including black holes for the first time in a large-scale cosmological simulation, physicists uncover their function in regulating the growth of galaxies

Fixing Blackholes by Tiziana di Matteo
Most Detailed Cosmoligal Simulation to Date from Carnegie Mellon
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Evolution of structure from Universe Today
Predicting where to aim future telescopes from Sciene Daily
Europe Plays Lead Role In New Age Of Astronomical Discovery
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The Big Bounce

What Happened Before The Big Bang?
Gazing Ball by qwerty

The idea that the universe erupted with a Big Bang explosion has been a big barrier in scientific attempts to understand the origin of our expanding universe, although the Big Bang long has been considered by physicists to be the best model. As described by Einstein's Theory of General Relativity, the origin of the Big Bang is a mathematically nonsensical state -- a "singularity" of zero volume that nevertheless contained infinite density and infinitely large energy.

Physicists at Penn State are exploring territory unknown even to Einstein -- the time before the Big Bang -- using a mathematical time machine called Loop Quantum Gravity. This theory, which combines Einstein's Theory of General Relativity with equations of quantum physics that did not exist in Einstein's day, is the first mathematical description to systematically establish the existence of the Big Bounce and to deduce properties of the earlier universe from which our own may have sprung. For scientists, the Big Bounce opens a crack in the barrier that was the Big Bang.
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"Einstein's Theory of General Relativity does not include the quantum physics that you must have in order to describe the extremely high energies that dominated our universe during its very early evolution," Martin Bojowald, assistant professor of physics at Penn State explained, "but we now have Loop Quantum Gravity, a theory that does include the necessary quantum physics."

Loop Quantum Gravity was pioneered and is being developed in the Penn State Institute for Gravitational Physics and Geometry, and is now a leading approach to the goal of unifying general relativity with quantum physics. Scientists using this theory to trace our universe backward in time have found that its beginning point had a minimum volume that is not zero and a maximum energy that is not infinite. As a result of these limits, the theory's equations continue to produce valid mathematical results past the point of the classical Big Bang, giving scientists a window into the time before the Big Bounce.

Quantum-gravity theory indicates that the fabric of space-time has an "atomic" geometry that is woven with one-dimensional quantum threads. This fabric tears violently under the extreme conditions dominated by quantum physics near the Big Bounce, causing gravity to become strongly repulsive so that, instead of vanishing into infinity as predicted by Einstein's Theory of General Relativity, the universe rebounded in the Big Bounce that gave birth to our expanding universe. The theory reveals a contracting universe before the Big Bounce, with space-time geometry that otherwise was similar to that of our universe today.

Bojowald found he had to create a new mathematical model to use with the theory of Loop Quantum Gravity in order to explore the universe before the Big Bounce with more precision. "A more precise model was needed within Loop Quantum Gravity than the existing numerical methods, which require successive approximations of the solutions and yield results that are not as general and complete as one would like," Bojowald explained. He developed a mathematical model that produces precise analytical solutions by solving of a set of mathematical equations.

In addition to being more precise, Bojowald's new model also is much shorter. He reformulated the quantum-gravity models using a different mathematical description, which he says made it possible to solve the equations explicitly and also turned out to be a strong simplification. "The earlier numerical model looked much more complicated, but its solutions looked very clean, which was a clue that such a mathematical simplification might exist," he said. Bojowald reformulated quantum gravity's differential equations -- which require many calculations of numerous consecutive small changes in time -- into an integrable system -- in which a cumulative length of time can be specified for adding up all the small incremental changes.

The model's equations require parameters that describe the state of our current universe accurately so that scientists then can use the model to travel backward in time, mathematically "un-evolving" the universe to reveal its state at earlier times. The model's equations also contain some "free" parameters that are not yet known precisely but are nevertheless necessary to describe certain properties. Bojowald discovered that two of these free parameters are complementary: one is relevant almost exclusively after the Big Bounce and the other is relevant almost exclusively before the Big Bounce. Because one of these free parameters has essentially no influence on calculations of our current universe, Bojowald colludes that it cannot be used as a tool for back-calculating its value in the earlier universe before the Big Bounce.

The two free parameters, which Bojowald found were complementary, represent the quantum uncertainty in the total volume of the universe before and after the Big Bang. "These uncertainties are additional parameters that apply when you put a system into a quantum context such as a theory of quantum gravity," Bojowald said. "It is similar to the uncertainty relations in quantum physics, where there is complimentarity between the position of an object and its velocity -- if you measure one you cannot simultaneously measure the other."

Similarly, Bojowald's study indicates that there is complementarity between the uncertainty factors for the volume of the universe before the Big Bounce and the universe after the Big Bounce. "For all practical purposes, the precise uncertainty factor for the volume of the previous universe never will be determined by a procedure of calculating backwards from conditions in our present universe, even with most accurate measurements we ever will be able to make," Bojowald explained. This discovery implies further limitations for discovering whether the matter in the universe before the Big Bang was dominated more strongly by quantum or classical properties.

"A problem with the earlier numerical model is you don't see so clearly what the free parameters really are and what their influence is," Bojowald said. "This mathematical model gives you an improved expression that contains all the free parameters and you can immediately see the influence of each one," he explained. "After the equations were solved, it was rather immediate to reach conclusions from the results."

Bojowald reached an additional conclusion after finding that at least one of the parameters of the previous universe did not survive its trip through the Big Bounce -- that successive universes likely will not be perfect replicas of each other. He said, "the eternal recurrence of absolutely identical universes would seem to be prevented by the apparent existence of an intrinsic cosmic forgetfulness."

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The Planck Scale from Bee @ Backreaction
Before the big bang from Universe Today
Against Bounces counterargument from Sean @ Cosmic Variance
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Event Horizon & BlackHoles

Astronomers May Have Solved Information Loss Paradox To Find Black Holes Do Not Form



"Nothing there," is what Case Western Reserve University physicists concluded about black holes after spending a year working on complex formulas to calculate the formation of new black holes.

The question that the physicists set out to solve is: what happens once something collapses into a black hole. If all information about the collapsing matter is lost, it defies the laws of quantum physics. Yet, in current thinking, once the matter goes over the event horizon and forms a black hole, all information about it is lost.
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Case physicists Tanmay Vachaspati, Dejan Stojkovic and Lawrence M. Krauss report in the article, "Observation of Incipient Black Holes and the Information Loss Problem," that has been accepted for publication by Physical Review D. "It's complicated and very complex," noted the researchers, regarding both the general problem and their particular approach to try to solve it.

"If you define the black hole as some place where you can lose objects, then there is no such thing because the black hole evaporates before anything is seen to fall in," said Vachaspati.
The masses on the edge of the incipient black hole continue to appear into infinity that they are collapsing but never fall over inside what is known as the event horizon, the region from which there is no return, according to the researchers.

By starting out with something that was nonsingular and then collapsing that matter, they were determined to see if an event horizon formed, signaling the creation of a black hole.
The mass shrinks in size, but it never gets to collapse inside an event horizon due to evidence of pre-Hawking radiation, a non-thermal radiation that allows information of the nature of what is collapsing to be recovered far from the collapsing mass.

"Non-thermal radiation can carry information in it unlike thermal radiation. This means that an outside observer watching some object collapse receives non-thermal radiation back and may be able to reconstruct all the information in the initial object and so the information never gets lost," they said.

According to the researchers, if black holes exist, information formed in the initial state would disappear in the black hole through a burst of thermal radiation that carries no information about the initial state.

Using the functional Schrodinger formalism, the researchers suggest that information about the energy from radiation is long evaporated before an event horizon forms.

"An outside observer will never lose an object down a black hole," said Stojkovic. "If you are sitting outside and throwing something into the black hole, it will never pass over but will stay outside the event horizon even if one considers the effects of quantum mechanics. In fact, since in quantum mechanics the observer plays an important role in measurement, the question of formation of an event horizon is much more subtle to consider."

The physicists are quick to assure astronomers and astrophysicists that what is observed in gravity pulling masses together still holds true, but what is controversial about the new finding is that "from an external viewer's point it takes an infinite amount of time to form an event horizon and that the clock for the objects falling into the black hole appears to slow down to zero," said Krauss, director of Case's Center for Education and Research in Cosmology.

He continued "this is one of the factors that led us to rethink this problem, and we hope our proposal at the very least will stimulate a broader reconsideration of these issues."

Adapted from a news release by Case Western Reserve University.

If black holes exist in the universe, the astrophysicists speculate they were formed only at the beginning of time.
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Rogue Black Holes

Astronomers are hunting an elusive target: rogue black holes that have been ejected from the centers of their home galaxies.

Some doubted that the quarry could be spotted, since a black hole must be gobbling matter from an accretion disk in order for that matter to shine. (Image Credit: NASA)

And if a black hole is ripped from the core of its home galaxy and sent hurling into the outskirts, the thinking goes, then its accretion disk might be left behind.

New calculations by theorist Avi Loeb (Harvard-Smithsonian Center for Astrophysics) give black hole hunters a reason to hope. Loeb showed that, generically, a black hole ejected from the center of a galaxy could bring its accretion disk along for the ride and remain visible for millions of years.

"Matter in the disk is swirling around the black hole much faster than the typical black-hole ejection speed. That matter is so tightly bound that it follows the black hole like a herd of sheep around a shepherd," said Loeb.

In the scenario examined by Loeb, two galaxies collide and merge. The spinning, supermassive black holes at the core of each galaxy coalesce, emitting powerful gravitational radiation in a preferred direction. Computer simulations recently demonstrated that the net momentum carried by the radiation gives the remnant black hole a large kick in the opposite direction. The black hole recoils at speeds of up to ten million miles per hour -- fast enough to traverse an entire galaxy in a cosmically short time of only ten million years.
[+/-] Click here to expand

Although the prediction of recoiling black holes in galaxy mergers has been shown to be robust, it was unclear until Loeb's paper whether the phenomenon could have optically observable consequences. Loeb examined the question of whether the black hole could hold onto its accretion disk while being ejected. He found that as long as the gas within the disk was orbiting at a speed far greater than the black hole ejection speed, the accretion disk would follow the black hole on its journey.

Moreover, the gaseous disk should not be consumed during the earlier binary coalescence phase that precedes the ejection because the black hole binary tends to open a cavity in the disk, like a spinning blade in a food processor.

After the two black holes join to become one, the accretion disk could feed the remnant black hole for millions of years, allowing the black hole to shine brilliantly. Such black holes at cosmological distances are called quasars.

Before the black hole's fuel is exhausted, it could travel more than 30,000 light-years from the center of its galaxy. At typical cosmological distances, that would equate to a separation on the sky of about one arcsecond (the size of a dime viewed from one mile away). Such separations are challenging to detect, since the quasar's brightness may overwhelm the fainter galaxy.

The powerful release of energy by a quasar shapes the evolution of its host galaxy. Previous theoretical calculations assumed that a quasar is pinned to the center of its galaxy where most of the gas concentrates. "However, the feedback from a recoiled quasar would be distributed along its trajectory, and would resemble the visible track of a subatomic particle in a bubble chamber," commented Loeb.

His paper argues that although most of the kicked black holes would remain bound to their host galaxies, their feedback and growth would be different than previously envisioned.

"Most importantly, this work is a good motivation for observers to search for displaced quasars," added Loeb.

Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for Astrophysics (CfA) is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe.

How to Spot the Speediest Black Holes CfA press release.

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Survival time inside the event horizon of a black hole from Universe Today
No Way Back: Maximizing survival time below the Schwarzschild event horizon
GRB's active longer than previously thought from Science Daily
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Blackholes in Colliding Galaxies

Adaptive Optics Pinpoints Two Supermassive Black Holes In Colliding Galaxies

Astronomers have used powerful adaptive optics technology at the W. M. Keck Observatory in Hawaii to reveal the precise locations and environments of a pair of supermassive black holes at the center of an ongoing collision between two galaxies 300 million light-years away.

NGC 6240 is an ongoing collision of two gas-rich disk galaxies. Using adaptive optics at the Keck II Telescope, researchers have resolved young star clusters formed because of the merger (small blue dots), and have identified which features within the twin nuclei are associated with the two supermassive black holes known to inhabit the nuclear regions. The green vertical line represents one second of arc, or 1,600 light years at the distance of NGC 6240.
(Credit: C. Max, G. Canalizo, W. de Vries)
[+/-] Click here to expand

The new observations of the galaxy merger known as NGC 6240 reveal that each of the black holes resides at the center of a rotating disk of stars and is surrounded by a cloud of young star clusters formed in the merger, said Claire Max, professor of astronomy and astrophysics at the University of California, Santa Cruz.

"People had observed this pair of colliding galaxies at different wavelengths and seen what they thought were the black holes, but it's been very hard to make sense of how the observations at various wavelengths correspond to each other," Max said. "The adaptive optics results enabled us to tie it all together, so now we can really see it all--the hot dust in the infrared, the stars in the visible and infrared, and the x-rays and radio emissions coming from right around the black holes."

Adaptive Optics (AO) enables astronomers to counteract the blurring effects of turbulence in Earth's atmosphere, which degrades images seen by ground-based telescopes. Max, who directs the Center for Adaptive Optics at UC Santa Cruz, is the lead author of a paper describing the new findings published by the journal Science. Her coauthors are Gabriela Canalizo, who worked with Max as a postdoctoral researcher at Lawrence Livermore National Laboratory (LLNL) and is now at UC Riverside, and Willem de Vries, a physicist with LLNL and UC Davis.

Images of NGC 6240 in visible light from the Hubble Space Telescope show the outer parts of the colliding galaxies distorted by their ongoing merger into long tidal tails of stars, gas, and dust. In the bright central region, two distinct nuclei can be discerned, but clouds of dust obscure much of the visible light from the core. The presence of two supermassive black holes in NGC 6240 was first demonstrated by x-ray observations from NASA's Chandra X-ray Observatory in 2002. Two pointlike radio sources were also detected in the central region.

But trying to match up the data from one instrument with those obtained at different wavelengths by other instruments is very difficult because there are few common reference points in the various wavelength regimes, Max said. The infrared images her group obtained using the AO system on the 10-meter Keck II Telescope provided the high spatial resolution needed to identify features in NGC 6240 that can be seen in different wavelengths.

"With the infrared images we got at Keck, we were able to line up the information from all the different wavelengths to determine which features in the images are the black holes," Max said.

The infrared wavelengths are less affected by dust than visible light, and the Keck infrared images show distinct nuclei with complex substructure surrounded by many faint point sources. The faint point sources are young star clusters produced in a burst of star formation triggered by the collision of the two gas-rich galaxies. Pinpointing which of the features in the infrared images correspond to the positions of the black holes involved several steps and required Keck adaptive optics observations at different infrared wavelengths.

"We uncovered it piece by piece, until we were able to make the correspondence between the black holes and the features seen at different wavelengths, as well as the stuff around them," Max said. "It really shows how powerful the Keck adaptive optics system is. We were also fortunate to have an extraordinarily good observing night."

Galaxy mergers are thought to play a major role in the evolution of galaxies and may help explain many of their properties. For example, astronomers have found that the mass of the black hole at the center of a galaxy is highly correlated with large-scale properties of the galaxy itself. The "coevolution" hypothesis explains this correlation as the result of both the black hole and the galaxy around it growing incrementally in repeated merger events over cosmic timescales.

"The gravitational influence of the black hole is actually limited to a relatively small region right around it, so how can it affect the rest of the galaxy" But if the black hole and the galaxy around it evolved together through the same sequence of merger events, that would explain the correlations," Max said. "That's why people are so excited about understanding galaxy mergers, and here we're seeing it in action."

The two black holes in NGC 6240 will eventually, in 10 million to 100 million years, spiral into each other and merge, producing a powerful burst of gravitational radiation, she said.

Story adapted from University of California - Santa Cruz news release

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X-rays provide a new way to investigate exploding stars from ESA
Slicing the Universe with HARP/ACSIS - A New Look at Orion from SciTech
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Weighing Blackholes

Artists Impression of Black Hole. Credits: NASA

ESA's XMM-Newton has helped to find evidence for the existence of controversial Intermediate Mass Black Holes. Scientists used a new, recently proven method for determining the mass of black holes.

Nikolai Shaposhnikov and Lev Titarchuk, at NASA’s Goddard Space Flight Center (GSFC), have used the technique to determine the mass of the black hole, Cygnus X-1, located in the constellation Cygnus (the Swan) approximately 10 000 light years away in our Galaxy, the Milky Way.

The elegant technique, first suggested by Titarchuk in 1998, shows that Cygnus X-1, part of a binary system, contains 8.7 solar masses, with a margin of error of only 0.8 solar masses. Cygnus X-1 was one of the first compelling black hole candidates to emerge in the early 1970s. The system consists of a blue supergiant and a massive but invisible companion.


Credits: NASA / Honeywell Max-Q Digital Group / Dana Berry

Artist’s impression of a binary system akin to Cygnus X-1. It consists of a blue supergiant star (right) and a black hole. The black hole is surrounded by a gaseous accretion disk that is fed by the star. Some black holes emit jets along the polar axis, as shown here.

The existence of IMBHs is controversial because there is no widely accepted mechanism for how they could form. But they would fill in a huge gap between black holes such as Cygnus X-1 - which form from collapsing massive stars and contain perhaps 5 to 20 solar masses - and the 'monsters' (up to thousand million solar masses) that lurk in the cores of large galaxies.

Titarchuk’s method takes advantage of a relationship between a black hole and its surrounding accretion disk. Gas orbiting in these disks eventually spirals into the black hole. When a black hole’s accretion rate increases to a high level, material piles up near the black hole in a hot region that Titarchuk likens to a traffic jam.

Titarchuk has shown that the distance from the black hole where this congestion occurs scales directly with the mass of the black hole. The more massive the black hole, the farther this congestion occurs and the longer the orbital period.

In his model, hot gas piling up in the congestion region is linked to observations of X-ray intensity variations that repeat on a nearly, but not perfectly, periodic basis. These Quasi-Periodic Oscillations (QPOs) are observed in many black hole systems. The QPOs are accompanied by simple, predictable changes in the system’s spectrum as the surrounding gas heats and cools in response to the changing accretion rate.

New technique for ‘weighing’ black holes ESA Press Release
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Echoes from darkness by Louise Riofrio
A Ring of Dark Matter from Centauri Dreams
Hubble finds Ring of Dark Matter? Hubble Press Release
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Black Hole Eclipse

Chandra observations of the galaxy NGC 1365 have captured a remarkable eclipse of the supermassive black hole at its center. A dense cloud of gas passed in front of the black hole, which blocked high-energy X-rays from material close to the black hole. This serendipitous alignment allowed astronomers to measure the size of the disk of material around the black hole, a relatively tiny structure on galactic scales.

Astronomers were able to measure the disk's size by observing how long it took for the black hole to go in and out of the eclipse. This was revealed during a series of observations of NGC 1365 obtained every two days over a period of two weeks in April 2006. During five of the observations, high-energy X-rays from the central X-ray source were visible, but in the second one - corresponding to the eclipse - they were not.




The Chandra image contains a bright X-ray source in the middle, which reveals the position of the supermassive black hole. An optical view of the galaxy from the European Space Observatory's Very Large Telescope shows the context of the Chandra data.

NGC 1365 contains a so-called active galactic nucleus, or AGN. Scientists believe that the black hole at the center of the AGN is fed by a steady stream of material, presumably in the form of a disk.

Material just about to fall into a black hole should be heated to millions of degrees before passing over the event horizon, or point of no return. The process causes the disk of gas around the central black hole in NGC 1365 to produce copious X-rays, but the structure is much too small to resolve directly with a telescope.

NGC 1365 is about 60 million light years
in the Constellation of Fornax (furnace).

Chandra Sees Remarkable Eclipse Of Black Hole from Science Daily 12th April 2007
More Images of NGC 1365 Eclipse from Chandra X-Ray Observatory
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Galaxy Mergers

Composite image of: Chandra X-ray Image of 3C442A and VLA Radio Image of 3C442A

About 390 million light years away in the Constellation of Pegasus The Winged horse - Two galaxies near the middle of 3C442A in the process of merging.

These two galaxies are on their second pass toward a collision, having already experienced a close encounter. The energy generated from this impending merger is heating the combined atmospheres from these two galaxies, causing them to shine brightly in X-rays and expand.

Researchers have determined that the jets that had produced the lobes of radio-emitting gas are no longer active. The jets may have ceased at the time of, and possibly as a result of, the galaxy collision. Since the radio-emitting gas no longer has a power source, it is then at the mercy of the expanding hot gas and has been pushed aside.

More Images of 3C442A from Chandra X-Ray Observatory
Credit: X-ray: NASA/CXC/Univ. of Bristol/Worrall et al.; Radio: NRAO/AUI/NSF
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Dust Clouds In Cosmic Cycle from Science Daily
Testing Relativity from Astroprof @ Astroprof's Page
X-ray satellites catch magnetar in gigantic stellar ‘hiccup’ from ESA
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Akari Results

Wealth of new results from AKARI infrared sky-surveyor
This artist’s concept illustrates the possible structure of the central core of the galaxy UGC05101 situated in the constellation Ursa Major , approximately 550 million light years away from the Earth. Termed an ‘ultraluminous infrared galaxy,’ the total energy it emits in the infrared alone is about one trillion times more than the that of the Sun. However, the central region is covered by a thick interstellar medium and can only be observed in the Infrared. Observations with AKARI have revealed evidence for active phenomena in the central part of this galaxy.

It has been postulated that at the centre of UGC05101 is a giant black hole, of mass more than a million times that of our Sun. In this case, the material around it would be expected to radiate enormous amounts of energy as it slowly tumbles into the black hole.

Credits: JAXA
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Scientists Compute Death Throes Of White Dwarf Star In 3D
The Purple Rose of Virgo VLT Image of Bright Supernova - from ESO
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