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NASA may have witnessed the birth of a black hole for the first time ever

NASA may have witnessed the birth of a black hole for the first time ever | Science Communication from mdashf | Scoop.it

Black holes are created when a supernova explosion destroys a massive star. Scientists have discovered dozens of black holes, but all of them are already formed. So, when scientists recently saw different distorted remains of a supernova, they knew it something special.

 

What the scientists believe they observed was the infant phases of a black hole, or the youngest black hole ever recorded in the Milky Way galaxy.

Caught on film by NASA's Chandra X-ray Observatory, the "remnant," or W49B, is seen as a vibrant swirl of blues, greens, yellows, and pinks. As seen from Earth, it is about 1,000-years-old and is located roughly 26,000 light years away. A typical black hole, like SS433, is thought to be between 17,000- and 21,000-years-old, as seen from Earth.

 

"W49B is the first of its kind to be discovered in the galaxy," Laura Lopez, who led a study on the remnant at the Massachusetts Institute of Technology, said in a statement. "It appears its parent star ended its life in a way that most others don't."


Via Dr. Stefan Gruenwald
mdashf's insight:

right when it was borne 

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Einstein Was Right: Space-Time Is Smooth And Not Foamy

Einstein Was Right: Space-Time Is Smooth And Not Foamy | Science Communication from mdashf | Scoop.it
A new study supports Einstein's view over that of some quantum theorists.

 

A team of researchers came to this conclusion after tracing the long journey three photons took through intergalactic space. The photons were blasted out by an intense explosion known as a gamma-ray burst about 7 billion light-years from Earth. They finally barreled into the detectors of NASA's Fermi Gamma-ray Space Telescope in May 2009, arriving just a millisecond apart.

Their dead-heat finish strongly supports the Einsteinian view of space-time, researchers said. The wavelengths of gamma-ray burst photons are so small that they should be able to interact with the even tinier "bubbles" in the quantum theorists' proposed space-time foam.

 

If this foam indeed exists, the three protons should have been knocked around a bit during their epic voyage. In such a scenario, the chances of all three reaching the Fermi telescope at virtually the same time are very low, researchers said.

 

So the new study is a strike against the foam's existence as currently imagined, though not a death blow. "If foaminess exists at all, we think it must be at a scale far smaller than the Planck length, indicating that other physics might be involved," study leader Robert Nemiroff, of Michigan Technological University, said in a statement. The Planck length is an almost inconceivably short distance, about one trillionth of a trillionth the diameter of a hydrogen atom. 

 

"There is a possibility of a statistical fluke, or that space-time foam interacts with light differently than we imagined," added Nemiroff, who presented the results Wednesday (Jan. 9) at the 221st meeting of the American Astronomical Society in Long Beach, Calif.


Via Dr. Stefan Gruenwald
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Most powerful black hole blast discovered - 100 times the energy of whole Milky Way ejected

Most powerful black hole blast discovered - 100 times the energy of whole Milky Way ejected | Science Communication from mdashf | Scoop.it

Astronomers analysed the energy being carried away from a huge quasar – the bright centres of distant galaxies which are powered by supermassive black holes and spew out vast amounts of matter.

 

Scientists have long claimed that extraordinarily powerful quasars must exist and play a key role in the formation of new galaxies, but until now none had been discovered which came close to their predictions.


Now measurements of a quasar known as SDSS J1106+1939 have established that it releases energy with about two million million times the power output of the Sun – the type of very high energy proposed by theorists. The team of scientists, who made their observations using the European Southern Observatory's Very Large Telescope (VLT), calculated that a mass equivalent to 400 Suns is given off by the quasar each year, at a speed of 800km per second. Dr. Nahum Arav of Virginia Tech University, who led the study, said: “We have discovered the most energetic quasar outflow known to date ... I’ve been looking for something like this for a decade, so it’s thrilling to finally find one of the monster outflows that have been predicted."


Theorists claim that the existence of quasars with such a powerful outflow of energy could solve a number of unanswered questions in cosmology, such as how the central black hole mass of galaxies helps determine the overall mass of the galaxy, and why the universe has so few very large galaxies.


Until now it was unclear whether quasars were powerful enough to produce such vast galaxies as some seen in the distant universe, but the researchers established that both SDSS J1106+1939 and one other quasar each have tremendous outflows.

 

They are now studying a further 12 similar quasars to determine whether the same is true of other luminous quasars spread across the universe.


Via Dr. Stefan Gruenwald
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Astronomers discover the largest structure in the universe - 4 Billion light years across

Astronomers discover the largest structure in the universe - 4 Billion light years across | Science Communication from mdashf | Scoop.it

An international team of astronomers, led by academics from the University of Central Lancashire (UCLan), has found the largest known structure in the universe. The large quasar group (LQG) is so large that it would take a vehicle travelling at the speed of light some 4 billion years to cross it. The team publish their results in the journal Monthly Notices of the Royal Astronomical Society.

 

Quasars are the nuclei of galaxies from the early days of the universe that undergo brief periods of extremely high brightness that make them visible across huge distances. These periods are 'brief' in astrophysics terms but actually last 10-100 million years. Since 1982 it has been known that quasars tend to group together in clumps or 'structures' of surprisingly large sizes, forming large quasar groups or LQGs.

 

The team, led by Dr. Roger Clowes from UCLan's Jeremiah Horrocks Institute, has identified the LQG which is so significant in size it also challenges the Cosmological Principle: the assumption that the universe, when viewed at a sufficiently large scale, looks the same no matter where you are observing it from.

 

The modern theory of cosmology is based on the work of Albert Einstein, and depends on the assumption of the Cosmological Principle. The Principle is assumed but has never been demonstrated observationally 'beyond reasonable doubt'.

 

To give some sense of scale, our galaxy, the Milky Way, is separated from its nearest neighbour, the Andromeda Galaxy, by about 0.75 Megaparsecs (Mpc) or 2.5 million light-years. Whole clusters of galaxies can be 2-3 Mpc across but LQGs can be 200 Mpc or more across. Based on the Cosmological Principle and the modern theory of cosmology, calculations suggest that astrophysicists should not be able to find a structure larger than 370 Mpc.

 

Dr. Clowes' newly discovered LQG however has a typical dimension of 500 Mpc. But because it is elongated, its longest dimension is 1200 Mpc (or 4 billion light years) - some 1600 times larger than the distance from the Milky Way to Andromeda.

 

 


Via Dr. Stefan Gruenwald
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Early universe: Magnetic fields created before the first stars

Early universe: Magnetic fields created before the first stars | Science Communication from mdashf | Scoop.it
Magnets have practically become everyday objects. Earlier on, however, the universe consisted only of nonmagnetic elements and particles. Just how the magnetic forces came into existence has now been researched.

 

Before the formation of the first stars, the luminous matter consisted only of a fully ionised gas of protons, electrons, helium nuclei and lithium nuclei which were produced during the Big Bang. "All higher metals, for example, magnetic iron could, according to today's conception, only be formed in the inside of stars," says Reinhard Schlickeiser. "In early times therefore, there were no permanent magnets in the Universe." The parameters that describe the state of a gas are, however, not constant. Density and pressure, as well as electric and magnetic fields fluctuate around certain mean values. As a result of this fluctuation, at certain points in the plasma weak magnetic fields formed -- so-called random fields. How strong these fields are in a fully ionised plasma of protons and electrons, has now been calculated by Prof. Schlickeiser, specifically for the gas densities and temperatures that occurred in the plasmas of the early universe.

 

The result: the magnetic fields fluctuate depending on their position in the plasma, however, regardless of time -- unlike, for example, electromagnetic waves such as light waves, which fluctuate over time. Everywhere in the luminous gas of the early universe there was a magnetic field with a strength of 10^-20 Tesla, i.e. 10 sextillionth of a Tesla. By comparison, the earth's magnetic field has a strength of 30 millionths of a Tesla. In MRI scanners, field strengths of three Tesla are now usual. The magnetic field in the plasma of the early universe was thus very weak, but it covered almost 100 percent of the plasma volume.

 

Stellar winds or supernova explosions of the first massive stars generated shock waves that compressed the magnetic random fields in certain areas. In this way, the fields were strengthened and aligned on a wide-scale. Ultimately, the magnetic force was so strong that it in turn influenced the shock waves. "This explains the balance often observed between magnetic forces and thermal gas pressure in cosmic objects," says Prof. Schlickeiser. The calculations show that all fully ionised gases in the early universe were weakly magnetised. Magnetic fields therefore existed even before the first stars. Next, the Bochum physicist is set to examine how the weak magnetic fields affect temperature fluctuations in the cosmic background radiation.


Via Dr. Stefan Gruenwald
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Scientists report new dark matter finding from merging galaxy cluster

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

 

Astronomers have abundant evidence that an as-yet-unidentified form of matter is responsible for 90 percent of the gravity within galaxies and clusters of galaxies. Because it is detected via its gravity and not its light, they call it "dark matter." Now, a new observation of Abell 520 from another team of astronomers using a different Hubble camera finds that the core does not appear to be over-dense in dark matter after all. The study findings were published in The Astrophysical Journal.

 

"The earlier result presented a mystery. In our observations we didn't see anything surprising in the core," said study leader Douglas Clowe, an associate professor of physics and astronomy at Ohio University. "Our measurements are in complete agreement with how we would expect dark matter to behave."

 

Hubble observations announced earlier this year by astronomers using Hubble's Wide Field Planetary Camera 2 suggested that a clump of dark matter was left behind during a clash between massive galaxies clusters in Abell 520, located 2.4 billion light-years away. The dark matter collected into a "dark core" that contained far fewer galaxies than would be expected if the dark and luminous matter were closely connected, which is generally found to be the case. Because dark matter is not visible, its presence and distribution is found indirectly through its gravitational effects. The gravity from both dark and luminous matter warps space, bending and distorting light from galaxies and clusters behind it like a giant magnifying glass. Astronomers can use this effect, called gravitational lensing, to infer the presence of dark matter in massive galaxy clusters. Both teams used this technique to map the dark matter in the merging cluster.


Via Dr. Stefan Gruenwald
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