Forget dark matter, STRANGE matter could be lurking somewhere in the universe


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  • Scientists at the National Institute for Space Research in Brazil say an undiscovered type of matter could be found in neutron stars
  • Here matter is so dense that it could be ‘squashed’ into strange matter
  • This would create an entire ‘strange star’ – unlike anything we have seen
  • However, the exact properties of strange matter are unknown
  • If it exists, though, it could help scientists discover ripples in space-time known as gravitational waves

Neutron stars are among the densest objects in the universe – just a spoonful of matter from one of them would weigh more than the moon.

But inside these remarkable stellar objects, which are no bigger than a city on Earth, a remarkable process might be taking place.

Scientists have revealed their matter might become so squashed that it turns into ‘strange matter’ – and observing so-called strange stars could unlock some of the secrets of the universe.

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Scientists at the National Institute for Space Research in Brazil say an undiscovered type of matter could be found in neutron stars (illustration shown). Here matter is so dense that it could be ‘squashed’ into strange matter. This would create an entire ‘strange star’ – unlike anything we have seen

The latest theory was proposed by Dr Pedro Moraes and Dr Oswaldo Miranda, both of the National Institute for Space Research in Brazil.

They say that some types of neutron stars might be made of a new type of matter called strange matter.

What the properties of this matter would be, though, are unknown – but it would likely be a ‘liquid’ of several types of sub-atomic particles.

Source: daily mail

A Pair of Black Holes Could Soon Collide And Destroy Their Galaxy


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One black hole is not to be messed with, let alone two. Astronomers have discovered what appears to be two supermassive black holes just one light-year apart, setting up a collision so massive it could be release as much energy as 100 million supernovas and destroy it’s inside galaxy . Yep.

A Supermassive Black Hole is the largest type of black hole, on the order of hundreds of thousands to billions of solar masses and are found in the center of almost all massive galaxies.In the case of the Milky Way, the Supermassive black hole is believed to correspond with the location of Sagittarius A*(At the center).

Thankfully, the black holes are far away in a remote galaxy called PG 1302-102. The collision itself, if astronomers have done the calculations right, will happen in the next million years. That’s a pretty unfathomably long time for humans, but just a blink of an eye in cosmic time.

Astronomers are excited about the discovery because a pair of black holes could yield valuable information about theorized but never directly detected gravitational waves. Gravitational waves are ripples in space-time that exist according to Einstein’s theory of general relativity. If the two black holes collide, most of the released energy will be in the form of gravitational waves, literally bending the fabric of space-time.

But for now, the pair of black holes still need to be 100 percent confirmed. When two black holes so far away are close to one another, astronomers on Earth can only see it as a particular flicker of light. Astronomers need to rule the flicker out as a statistical anomaly. Still, in the long history of the universe, black holes have almost certainly collided before. Destroying whole galaxies in one fell swoop is not just science fiction.

Source : gizmodo.com

‘Perfect Storm’ Suffocating Star Formation around a Supermassive Black Hole


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High-energy jets powered by supermassive black holes can blast away a galaxy’s star-forming fuel — resulting in so-called “red and dead” galaxies: those brimming with ancient red stars yet little or no hydrogen gas available to create new ones.

Now astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have discovered that black holes don’t have to be nearly so powerful to shut down star formation. By observing the dust and gas at the center NGC 1266, a nearby lenticular galaxy with a relatively modest central black hole, the astronomers have detected a “perfect storm” of turbulence that is squelching star formation in a region that would otherwise be an ideal star factory.

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Fig 1. Artist impression of the central region of NGC 1266. The jets from the central black hole are creating turbulence in the surrounding molecular gas, suppressing star formation in an otherwise ideal environment to form new stars. Credit: B. Saxton (NRAO/AUI/NSF)

This turbulence is stirred up by jets from the galaxy’s central black hole slamming into an incredibly dense envelope of gas. This dense region, which may be the result of a recent merger with another smaller galaxy, blocks nearly 98 percent of material propelled by the jets from escaping the galactic center.

“Like an unstoppable force meeting an immovable object, the molecules in these jets meet so much resistance when they hit the surrounding dense gas that they are almost completely stopped in their tracks,” said Katherine Alatalo, an astronomer with the California Institute of Technology in Pasadena and lead author on a paper published in the Astrophysical Journal. This energetic collision produces powerful turbulence in the surrounding gas, disrupting the first critical stage of star formation. “So what we see is the most intense suppression of star formation ever observed,” noted Alatalo.

Previous observations of NGC 1266 revealed a broad outflow of gas from the galactic center traveling up to 400 kilometers per second. Alatalo and her colleagues estimate that this outflow is as forceful as the simultaneous supernova explosion of 10,000 stars. The jets, though powerful enough to stir the gas, are not powerful enough to give it the velocity it needs to escape from the system.

Continue reading ‘Perfect Storm’ Suffocating Star Formation around a Supermassive Black Hole

The Fastest Stars in the Universe May Approach Light Speed


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Our sun orbits the Milky Way’s center at an impressive 450,000 mph. Recently, scientists have discovered stars hurtling out of our galaxy at a couple million miles per hour. Could there be stars moving even faster somewhere out there?

After doing some calculations, Harvard University astrophysicists Avi Loeb and James Guillochon realized that yes, stars could go faster. Much faster. According to their analysis, which they describe in two papers recently posted online, stars can approach light speed. The results are theoretical, so no one will know definitively if this happens until astronomers detect such stellar speedsters—which, Loeb says, will be possible using next-generation telescopes.

But it’s not just speed these astronomers are after. If these superfast stars are found, they could help astronomers understand the evolution of the universe. In particular, they give scientists another tool to measure how fast the cosmos is expanding. Moreover, Loeb says, if the conditions are right, planets could orbit the stars, tagging along for an intergalactic ride. And if those planets happen to have life, he speculates, such stars could be a way to carry life from one galaxy to another.

It all started in 2005 when a star was discovered speeding away from our galaxyfast enough to escape the gravitational grasp of the Milky Way. Over the next few years, astronomers would find several more of what became known as hypervelocity stars. Such stars were cast out by the supermassive black hole at the center of the Milky Way. When a pair of stars orbiting each other gets close to the central black hole, which weighs about four million times as much as the sun, the three objects engage in a brief gravitational dance that ejects one of the stars. The other remains in orbit around the black hole.

Loeb and Guillochon realized that if instead you had two supermassive black holes on the verge of colliding, with a star orbiting around one of the black holes, the gravitational interactions could catapult the star into intergalactic space at speeds reaching hundreds of times those of hypervelocity stars.

This appears to be the most likely scenario that would produce the fastest stars in the universe, Loeb says. After all, supermassive black holes collide more often than you might think. Nearly all galaxies have supermassive black holes at their centers, and nearly all galaxies were the product of two smaller galaxies merging. When galaxies combine, so do their central black holes.

Loeb and Guillochon calculated that merging supermassive black holes would eject stars at a wide range of speeds. Only some would reach near light speed, but many of the rest would still be plenty fast. For example, Loeb says, the observable universe could have more than a trillion stars moving at a tenth of light speed, about 67 million miles per hour.

Because a single, isolated star streaking through intergalactic space would be so faint, only powerful future telescopes like the James Webb Space Telescope , planned for launch in 2018, would be able to detect them. Even then, telescopes would likely only see the stars that have reached our galactic neighborhood. Many of the ejected stars probably would have formed near the centers of their galaxies, and would have been thrown out soon after their birth. That means that they would have been traveling for the vast majority of their lifetimes. The star’s age could therefore approximate how long the star has been traveling. Combining travel time with its measured speed, astronomers can determine the distance between the star’s home galaxy and our galactic neighborhood.

If astronomers can find stars that were kicked out of the same galaxy at different times, they can use them to measure the distance to that galaxy at different points in the past. By seeing how the distance has changed over time, astronomers can measure how fast the universe is expanding.

These superfast rogue stars could have another use as well. When supermassive black holes smash into each other, they generate ripples in space and time called gravitational waves, which reveal the intimate details of how the black holes coalesced. A space telescope called eLISA, scheduled to launch in 2028, is designed to detect gravitational waves. Because the superfast stars are produced when black holes are just about to merge, they would act as a sort of bat signal pointing eLISA to possible gravitational wave sources.

The existence of these stars would be one of the clearest signals that two supermassive black holes are on the verge of merging, says astrophysicist Enrico Ramirez-Ruiz of the University of California, Santa Cruz. Although they may be hard to detect, he adds, they will provide a completely novel tool for learning about the universe.

In about 4 billion years, our own Milky Way Galaxy will crash into the Andromeda Galaxy. The two supermassive black holes at their centers will merge, and stars could be thrown out. Our own sun is a bit too far from the galaxy’s center to get tossed, but one of the ejected stars might harbor a habitable planet. And if humans are still around, Loeb muses, they could potentially hitch a ride on that planet and travel to another galaxy. Who needs warp drive anyway?

Source : wired.com

5 Most Mysterious Objects in the Solar System


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What unsolved mysteries lurk out in the thick blackness of space? Presenting 5 mysterious celestial objects in our Solar System, including Comet ISON, the Black Knight Satellite, 1991 VG, Object X and Planet X / Nibiru.

Source : Dark5

Discovery of a Pulsar and Supermassive Black Hole Pairing Could Help Unlock the Enigma of Gravity


Last year, the very rare presence of a pulsar (named SGR J1745-2900) was also detected in the proximity of a supermassive black hole (Sgr A**, made up of millions of solar masses), but there is a combination that is still yet to be discovered: that of a pulsar orbiting a ‘normal’ black hole; that is, one with a similar mass to that of stars.

The intermittent light emitted by pulsars, the most precise timekeepers in the universe, allows scientists to verify Einstein’s theory of relativity, especially when these objects are paired up with another neutron star or white dwarf that interferes with their gravity. However, this theory could be analysed much more effectively if a pulsar with a black hole were found, except in two particular cases, according to researchers from Spain and India.

Pulsars are very dense neutron stars that are the size of a city (their radius approaches ten kilometres), which, like lighthouses for the universe, emit gamma radiation beams or X-rays when they rotate up to hundreds of times per second. These characteristics make them ideal for testing the validity of the theory of general relativity, published by Einstein between 1915 and 1916.

“Pulsars act as very precise timekeepers, such that any deviation in their pulses can be detected,” Diego F. Torres, ICREA researcher from the Institute of Space Sciences (IEEC-CSIC), explains to SINC. “If we compare the actual measurements with the corrections to the model that we have to use in order for the predictions to be correct, we can set limits or directly detect the deviation from the base theory.”

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These deviations can occur if there is a massive object close to the pulsar, such as another neutron star or a white dwarf. A white dwarf can be defined as the stellar remnant left when stars such as our Sun use up all of their nuclear fuel. The binary systems, comprised of a pulsar and a neutron star (including double pulsar systems) or a white dwarf, have been very successfully used to verify the theory of gravity.

Until now scientists had considered the strange pulsar/black hole pairing to be an authentic ‘holy grail’ for examining gravity, but there exist at least two cases where other pairings can be more effective. This is what is stated in the study that Torres and the physicist Manjari Bagchi, from the International Centre of Theoretical Sciences (India) and now postdoc at the IEEC-CSIC, have published in the Journal of Cosmology and Astroparticle Physics. The work also received an Honourable Mention in the 2014 Essays of Gravitation prize.

The first case occurs when the so-called principle of strong equivalence is violated. This principle of the theory of relativity indicates that the gravitational movement of a body that we test only depends on its position in space-time and not on what it is made up of, which means that the result of any experiment in a free fall laboratory is independent of the speed of the laboratory and where it is found in space and time.

The other possibility is if one considers a potential variation in the gravitational constant that determines the intensity of the gravitational pull between bodies. Its value is G = 6.67384(80) x 10-11 N m2/kg2. Despite it being a constant, it is one of those that is known with the least accuracy, with a precision of only one in 10,000.

In these two specific cases, the pulsar-black hole combination would not be the perfect ‘holy grail’, but in any case scientists are anxious to find this pair, because it could be used to analyse the majority of deviations. In fact, it is one of the desired objectives of X-ray and gamma ray space telescopes (such as Chandra, NuStar or Swift), as well as that of large radio telescopes that are currently being built, such as the enormous ‘Square Kilometre Array’ (SKA) in Australia and South Africa.

Source : Daily galaxy

Complex life may be possible in only 10% of all galaxies


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The universe may be a lonelier place than previously thought. Of the estimated 100 billion galaxies in the observable universe, only one in 10 can support complex life like that on Earth, a pair of astrophysicists argues. Everywhere else, stellar explosions known as gamma ray bursts would regularly wipe out any life forms more elaborate than microbes. The detonations also kept the universe lifeless for billions of years after the big bang, the researchers say.

“It’s kind of surprising that we can have life only in 10% of galaxies and only after 5 billion years,” says Brian Thomas, a physicist at Washburn University in Topeka who was not involved in the work. But “my overall impression is that they are probably right” within the uncertainties in a key parameter in the analysis.

WHAT IS GAMMA RAY BURST 

Gamma-ray bursts (GRBs) are flashes of gamma rays associated with extremely energetic explosions that have been observed in distant galaxies. They are the brightest electromagnetic events known to occur in the universe.Bursts can last from ten milliseconds to several minutes. A typical burst releases as much energy in a few seconds as the Sun will in its entire 10-billion-year lifetime. But all observed GRBs have originated from outside the Milky Way galaxy.

Scientists have long mused over whether a gamma ray burst could harm Earth. The bursts were discovered in 1967 by satellites designed to spot nuclear weapons tests and now turn up at a rate of about one a day. They come in two types. Short gamma ray bursts last less than a second or two; they most likely occur when two neutron stars or black holes spiral into each other. Long gamma ray bursts last for tens of seconds and occur when massive stars burn out, collapse, and explode. They are rarer than the short ones but release roughly 100 times as much energy. A long burst can outshine the rest of the universe in gamma rays, which are highly energetic photons.

Continue reading Complex life may be possible in only 10% of all galaxies

Mystery of the ‘spooky’ pattern in the universe: Scientists find that supermassive black holes are ALIGNED


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A European research team has found that the rotation axes of the central supermassive black holes in a sample of quasars are parallel to each other over distances of billions of light-years. An artist’s impression of the alignment is pictured

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Black holes are one of the strangest objects in the universe, preventing anything from escaping their grip – even light.

Now astronomers have discovered something even more peculiar about these enigmatic objects; they are aligned with each other over distances stretching billions of light-years

The remarkable observations were made by the Very Large Telescope (VLT) in Chile, which found an eerie alignment between enormous interstellar objects called quasars.

Quasars are galaxies with very active supermassive black holes at their centres. They shine more brightly than all the stars in the rest of their host galaxies put together.

A European research team has found that the rotation axes of the central supermassive black holes in a sample of quasars are parallel to each other over vast distances.

Source : Dailymail

Black hole at Milky Way center may be emitting mysterious neutrinos, NASA says


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The massive black hole at the heart of our milky galaxy may be churning out peculiar particles called neutrinos, NASA satellites have revealed. If verified, it would be the first time neutrinos have been traced to the darkest regions of spacetime.

The subatomic activity was first detected by three NASA satellites, which observe in x-ray light: the Chandra X-ray Observatory, the Swift gamma-ray mission, and the Nuclear Spectroscopic Telescope Array (NuSTAR), the space agency said in a press release.

Neutrinos, from the Italian “little ones”, live up to their namesake, as they are tiny by even subatomic standards. Carrying no charge, they are unaffected by the electromagnetic forces that affect charged particles such as electrons and protons.

As a result, they can travel across vast expanses of the universe without being absorbed by matter that crosses their path (in fact, billions of them pass through your body every second!) And without an electric charge, they are not deflected by magnetic fields when traveling across the universe.

While the earth is constantly buffeted by neutrinos from the sun, those originating from beyond our solar system can be millions or even billions of times more energetic. Scientists have long puzzled the origin of ultra-high energy and very high-energy neutrinos.

“Figuring out where high-energy neutrinos come from is one of the biggest problems in astrophysics today,” said Yang Bai of the University of Wisconsin in Madison, who co-authored a study about the results published in Physical Review D. “We now have the first evidence that an astronomical source – the Milky Way’s supermassive black hole – may be producing these very energetic neutrinos.”

By tracing neutrinos back to black holes, scientists will be one step closer to understanding how cosmic rays are made. These rays wreak havoc on microelectronics and life outside the protection of an atmosphere and magnetic field. Understanding their origin also provides deeper insight into how the universe works.

Continue reading Black hole at Milky Way center may be emitting mysterious neutrinos, NASA says

New Mission May Discover Hundreds of Black Holes Throughout the Universe


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A new mission may just discover hundreds of new black holes throughout the universe. Scientists have revamped two detectors that are scheduled to switch on in the U.S. next year that could help scientists pick up the faint ripples of black hole collisions millions of years ago, known as gravitational waves.

Black holes can’t be seen, but the new detectors should be able to act like giant microphones and pick up the remnants of black hole collisions.

The rapid spinning of black holes will cause the orbits to wobble, just like the last wobbles of a spinning top before it falls over,” said Mark Hannam, one of the researchers, in a news release. “These wobbles can make the black holes trace out wild paths around each other, leading to extremely complicated gravitational-wave signals. Our model aims to predict this behavior and help scientists find the signals in the detector data.”
The researchers created a theoretical model which aims to predict all potential gravitational-wave signals that might be found by detectors. In theory, this should help scientists by acting as a “spotter’s guide” and allow them to recognize the right waveforms.
“Sometimes the orbits of these spinning black holes look completely tangled up, like a ball of string,” said Hannam. “But if you imagine whirling around with the black holes, then it all looks much clearer, and we can write down equations to describe what is happening. It’s like watching a kid on a high-speed spinning amusement park ride, apparently waving their hands around. From the side lines, it’s impossible to tell what they’re doing. But if you site next to them, they might be sitting perfectly still, just giving you the thumbs up.”
The new model should help search for black hole mergers once the detectors switch on. That said, more work still needs to be done. The scientists hope to create enough simulations to capture enough combinations of black-hole masses and spin directions to understand the overall behavior of these complicated systems.

Source : science world report