Black Holes ejects matter into Cosmic abysses

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Cosmos is a complicated subject with a multitude of fascinating objects ranging from carbonaceous dust grains to quasars, but that don’t stop the cosmologists’ curiosity to stop thinking and researching about the most abysmal concepts of the Universe. We all live in a universe subjugated by unseen matters such as baryons, CMB photons, Cold Dark Matter (CDM), Dark Energy and all these species of the universe are concentrated into filaments that expanse around the brink of colossal voids.

Thought to be almost void until now, a group of scientists have come to conclusions that dark holes could contain as much as 20% of the ‘normal’ matter in the cosmos and that galaxies make up only 1/500th of the volume of the universe. Observing the cosmic microwave radiation and analyzing it, modern satellite observatories like COBE, WMAP and Planck have advanced our understanding of the universe’s composition. Current measurements suggest that ‘normal’ matter (i.e. the matter that makes up stars, planets, baryons, gas and dust) combine almost 4.9% of the total universe, whereas mysterious and unseen ‘dark’ matter join 26.8% and mysterious ‘dark energy’ constitute 68.3% of the universe.

Some fundamental research work mapped the positions of galaxies and their allied dark matter over large volumes, showing that they are in strings that make up a ‘cosmic web’. The scientific team explored it further, using data from the Illustris project, which is a large computer simulation of the evolution and formation of galaxies, used to measure the mass and volume of these strings and the galaxies within them.

Illustris simulates a cube of space in the universe, computing some 350 million light years on each side. It took the first variable as the age of a young universe, just 12 million years old, and the second variable was a small fraction of its current age. The data’s were simulated and the gravity and flow of matter changing the structure of the cosmos up to the present day were analysed. The simulation compacts with both normal and dark matter, with the most important effect being the gravitational pull of the dark matter.

After analyzing the data, the scientists concluded that 50% of the total mass of the universe is in the places where galaxies exist in, trampled into a volume of 0.2% of the universe we see, and a further 44% is in the enveloping strings. Just 6% is in the voids, which make up 80% of the volume.

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The most surprising thing that caught scientists’ attention were the 20% fraction of ‘normal’ matter filling up the voids. Super-massive black holes found at the center of galaxies are the reason behind this. Matters fall into the holes, thus getting converted into energy. The energy is then delivered into the surrounding gases and leads to enormous outflows of matter, expanding for hundreds of thousands of light years from the black holes, reaching far beyond the size of their host galaxies.

The result will not only help us to know about how voids with more ‘normal’ matter are filled than expected but might also explain the missing baryon problem, where astronomers do not see the amount of normal matter predicted by their models.

Further simulations using Illustris have been done, and the results are expected to come within few months, which will give us an auxiliary understanding of black holes and confirm the output. Whatever the outcome, it will be hard to see the matter in the voids, as this is likely to be fragile and too casual to emanate the X-rays that would make it detectable by satellites.

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Will the discovery of Gravitational waves ever help us detect the ripples of Big Bang?

 

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Detecting ripples in a space-time was not an easy task, after-all it took 50 years of trial and error, and 25 years perfecting a set of instruments so sensitive that could finally show a distortion in space-time millions of light years away. The discovery of gravitational waves have stirred the whole world of astronomy and have posed all sort of fascinating questions for astronomers regarding binary black-hole systems. Perhaps in a way it has opened a new field of gravitational physics which will revolutionize our understanding of the universe during its infancy.

The game has just started and now that we know how to measure gravitational waves, experiments like LIGO can be further enhanced to have a broader view of events happening in and around the cosmos that we have never been able to see before, such as mergers of super-massive black holes in the early universe. But the utmost question is that how far back can we really go? What about the gravitational waves that occurred moments after the big bang, will LIGO’s discovery help us catch those?

Let us take a step back in time, we are now in an era where the masses involved in the events are large by stellar standards, they are dwarfed by the super-massive black holes that scientists believe are present at the center of almost every galaxy. Our very own galaxy, the Milky Way, hosts a hole of about 4 million sun masses, detected through the motions of stars orbiting it.

There are yet a lot to discover about these super-massive black holes. We presently understand them through the immense amounts of electromagnetic radiation, like visible light and X-rays, produced by gas cascades into them. We know the likeliness of the process of formation of black holes, where some gasses are too slow and near and others are too fast and away for the black holes to capture it. So, the intriguing questions are that how could they get so big?

The answer could be that collisions between these super-massive holes helped to grow them, particularly when they were comparatively young and had not yet gained much gas. However, a collision between two super-massive black holes can probably only happen if the two galaxies hosting them collide and merge too. But these event is impossible to happen in the current time as because galaxies are far away from each other. But what if we go back in time, a time when the universe was much younger and the galaxies were very nearer to each other.

So detecting gravitational waves from such collisions means going back in time and analyzing the most distant galaxies giving us direct traces about how important these events were in growing super-massive black holes early in their lives and in turn unraveling the truth of mystery about the universe.

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But the collision of super-massive black-holes is not the end. The Big Bang, and particularly the eon of very rapid expansion dubbed inflation with enormous masses moving with almost light speed producing powerful gravitational waves are the goal we are looking forward to achieve. However, the most powerful signal comes from masses whose size is comparable to the scale of the universe itself. Since gravitational radiation has a typical wavelength larger than the masses emitting it, the “wavelength” of this radiation is itself similar to the entire size of the universe. So LIGO, or any other experiment that is smaller than the universe, will not be able to detect it.

The challenge is extremely difficult but a positive result could give evidence for the popular inflation theory, and offer explanations for several baffling features of the universe, such as why the distribution of matter is so standardized. Although finding such a signal is a colossal challenge, so was the direct detection of gravitational waves when first proposed half a century ago.

Can discovery of Gravitational waves unravel the mystery of quantum gravity?

With the discovery of gravitational waves, ripples in the fabric of space-time, scientists have finally been able to provide convincing evidence for the existence of black holes and confirming an enigmatic part of Einstein’s theory of relativity. The discovery is one of the most important climaxes of the century and may finally provide the fundamental understanding of the formation of the Universe.

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This article will not be related to gravitational waves fully, but will cover up another most important theory that has been the target of decades of study by physicists worldwide. If this idea is established, then the General Theory of Relativity can be combined with quantum mechanics eventually revolutionizing the field of subatomic particles.

Quantum gravity is a field of theoretical physics that deals with the force of gravity rendering to the principles of quantum mechanics, and where quantum effects cannot be ignored. Subatomic particles have different characteristics and some of them are quantized meaning they can only move or exist in particular whole number states. Many physicists believe gravitational waves are similarly quantized and are made up of individual quantum particles of gravity known as gravitons.

While there is no concrete proof of the existence of gravitons, quantized theories of matter may necessitate their existence. Some physicists believe that gravitons join together, forming gravitational waves that travel through space in the form of ripples. Like photons of light, gravitons are also considered massless and move at the speed of light.

In the center of black holes, effects of quantum gravity are predicted to be quite definite, however it is impossible to accumulate data from the events happening near a singularity. The scientists form LIGO (Laser Interferometer Gravitational Wave Observatory) used a set of instruments which was very sensitive, yet they could only identify a distortion in space-time, which is a thousandth the diameter of one atomic nucleus across a 4 km strip of laser-beam and mirror.

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LIGO Gravitational wave detected on Feb 11,2016

It is impossible for the LIGO detector or any advanced gravitational wave detector to detect a graviton in the space-time, leave alone proving the theory of relativity. But maybe in future a device so precisely modified is build, that it could finally detect the evidence of quantum gravity by examining the emission spectrum of energy surrounding the event horizons of black holes.

With LIGO , the astronomers have so far detected intangible ripples in space-time which is only the beginning of a new kind of physics. Further into the advancement of astronomical devices, they may come across other evidence of astrophysical theories such as cosmic strings, theoretical one-dimensional strings of energy, which may be there in the depth of space-time since the very beginning.

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The recorded data of the gravitational waves may also give the physicists to analyze the ripples in order to finally examine some evidence of gravitons which will eventually solve the mysterious puzzle of relativity theory. If the existence of gravitons is established, it could change the way of understanding gravity. Such a finding could suggest that other notions of gravity, such as string theory, could prove to be the basis of future work on the nature of gravity.

But until that time comes, the existence of gravitons are strictly theoretical.

Galactic climate being affected by Black Holes

A prevailing galactic explosion produced by a giant black hole situated almost 26 million light years away from Earth has provoked a new leap in the field of cosmology. This is one of the nearest super-massive black holes to Earth and its frequent violent outbursts can somehow change the galactic climate is been proposed by a team of researchers led by Eric Schlegel, Professor of Physics at The University of Texas at San Antonio.

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The inset image shows X-ray arcs that astronomers say are signs of galactic burping in the Messier 51 galaxy system

Schlegel’s team used NASA’s Earth-orbiting Chandra X-ray Observatory to locate the black hole blast in the famous Messier 51 system of galaxies. The Messier 51 system contains a large spiral galaxy, NGC 5194, colliding with a smaller companion galaxy, NGC 5195.

“Just as powerful storms here on Earth impact their environments, so too do the ones we see out in space,” Schlegel said. “This black hole is blasting hot gas and particles into its surroundings that must play an important role in the evolution of the galaxy.”

Schlegel and his colleagues, including Fisk University graduate student and UTSA alumna Laura Vega, detected two X-ray emission arcs near to the center of NGC 5195, where the super-massive black hole is located.

“We think these arcs represent artifacts from two enormous gusts when the black hole expelled material outward into the galaxy,” said co-author Christine Jones, astrophysicist, and lecturer at the Harvard-Smithsonian Center for Astrophysics. “We think this activity has had a big effect on the galactic landscape.”

The researchers detected a willowy region of hydrogen gas emission just beyond the outer arc, suggesting that X-ray emitting gas expatriate the hydrogen gas from the center of the galaxy.

Furthermore, the properties of the gas around the arcs propose that the outer arc has flounced up enough material to trigger the formation of new stars. This type of phenomenon, where a black hole affects its host galaxy, is called feedback. Continue reading