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Evidence mounts that neutrinos are the key to the universe's existence

Evidence mounts that neutrinos are the key to the universe's existence | Amazing Science |

New experimental results show a difference in the way neutrinos and antineutrinos behave, which could explain why matter persists over antimatter.


The results, from the T2K experiment in Japan, show that the degree to which neutrinos change their type differs from their antineutrino counterparts. This is important because if all types of matter and antimatter behave the same way, they should have obliterated each other shortly after the Big Bang.


So far, when scientists have looked at matter-antimatter pairs of particles, no differences have been large enough to explain why the universe is made up of matter – and exists – rather than being annihilated by antimatter.


Neutrinos and antineutrinos are one of the last matter-antimatter pairs to be investigated since they are difficult to produce and measure, but their strange behavior hints that they could be the key to the mystery.


Neutrinos (and antineutrinos) come in three ‘flavors’ of tau, muon and electron, each of which can spontaneously change into the other as the neutrinos travel over long distances. The latest results, announced today by a team of researchers including physicists from Imperial College London, show more muon neutrinos changing into electron neutrinos than muon antineutrinos changing into electron antineutrinos. This difference in muon-to-electron changing behavior between neutrinos and antineutrinos means they would have different properties, which could have prevented them from destroying each other and allow the universe to exist.

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Is Earthly life premature from a cosmic perspective?

Is Earthly life premature from a cosmic perspective? | Amazing Science |



"If you ask, 'When is life most likely to emerge?' you might naively say, 'Now,'" says lead author Avi Loeb of the Harvard-Smithsonian Center for Astrophysics. "But we find that the chance of life grows much higher in the distant future."


Life as we know it first became possible about 30 million years after the Big Bang, when the first stars seeded the cosmos with the necessary elements like carbon and oxygen. Life will end 10 trillion years from now when the last stars fade away and die. Loeb and his colleagues considered the relative likelihood of life between those two boundaries.


The dominant factor proved to be the lifetimes of stars. The higher a star's mass, the shorter its lifetime. Stars larger than about three times the sun's mass will expire before life has a chance to evolve.


Conversely, the smallest stars weigh less than 10 percent as much as the Sun. They will glow for 10 trillion years, giving life ample time to emerge on any planets they host. As a result, the probability of life grows over time. In fact, chances of life are 1000 times higher in the distant future than now.


"So then you may ask, why aren't we living in the future next to a low-mass star?" says Loeb. "One possibility is we're premature. Another possibility is that the environment around a low-mass star is hazardous to life."


Although low-mass, red dwarf stars live for a long time, they also pose unique threats. In their youth they emit strong flares and ultraviolet radiation that could strip the atmosphere from any rocky world in the habitable zone.


To determine which possibility is correct—our premature existence or the hazard of low-mass stars—Loeb recommends studying nearby red dwarf stars and their planets for signs of habitability. Future space missions like the Transiting Exoplanet Survey Satellite and James Webb Space Telescope should help to answer these questions.

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Understanding the Universe: Quanta, Symmetry, and Topology (speaker: Frank Wilczek, MIT)

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Dark energy measured with record-breaking map of 1.2 million galaxies

Dark energy measured with record-breaking map of 1.2 million galaxies | Amazing Science |














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First universe modeling using Einstein's full theory of general relativity











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Seeds of ancient black holes could be revealed by gravitational wave pattern









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The Inside of a Neutron Star Looks Spookily Familiar

The Inside of a Neutron Star Looks Spookily Familiar | Amazing Science |

Hot fluids of neutrons that flow without friction, superconductors made of protons, and a solid crust built of exotic atoms—features like these make neutron stars some of the strangest objects we’ve found in the cosmos so far. They pack all the mass of a star into a sphere the size of a city, resulting in states of matter we just don’t have on Earth. And yet, despite their extreme weirdness, neutron stars contain a mishmash of vaguely familiar features, as if seen darkly through a funhouse mirror. One of the weirdest is the fact that deep inside a neutron star you can find a whole menu full of nuclear pasta.


The pasta is made of protons and neutrons, held together by the extreme pressures. These oddball nuclei arrange themselves into weird configurations that Matt Caplan of Indiana University and his colleagues call “nuclear pasta.”1 The pasta layer lies in the inner crust, a transitional zone between a neutron star’s outer crust and core. In the top of this layer, the nuclei form blobs called “gnocchi.” Deeper down, they join together into cylindrical shapes called “spaghetti.” More pressure, and the spaghetti compresses into “lasagna”: flattish sheets of nuclear matter. Then the pasta transitions into “anti-pasta”: The sheets of lasagna form cylindrical hollows where neutrons begin leaking out, which Caplan calls “anti-spaghetti.” And finally, when the pressure is high enough, those hollows break into small bubbles, the “anti-gnocchi” phase.


Weirder still is the resemblance of the nuclear pasta to structures formed by certain biological molecules. These molecules are lipid polymers, which are found in fats. Because they are made of a water-loving and water-repelling layer sandwiched together, their interactions with a watery environment make them self-assemble into the spaghetti- and lasagna-like structures known as endoplasmic reticulum, found in complex (eukaryotic) cells.


The similarity is striking, even though the systems couldn’t appear more different in most respects. Nuclear pasta is roughly 100 trillion times denser than the interior of a cell—that’s 1014, or a 1 followed by 14 zeroes. The forces in a neutron star are strong electromagnetism and the nuclear forces; cells are governed by weaker molecular electric forces and the microscopic properties of water. Even the building blocks are different: The raw materials for nuclear pasta are protons and neutrons, while endoplasmic reticulum is made of long chains of molecules strung together.


Caplan says, “What’s in common is that they want to minimize surface energy.” Think of a soap bubble or a splash of water aboard the International Space Station: They form roughly spherical shapes. That’s because the surface forces draw the molecules together into spheres, which involve the lowest amount of energy on the surface. The forces that create nuclear pasta and endoplasmic reticulum aren’t as symmetrical, thanks to the competing attractive and repulsive interactions between the lasagna layers and the surrounding material. However, the laws of physics are still at work and want to minimize the energy involved. The result is blobs and folded sheets and cavities in the neutron star crust or the watery interior of a cell. The forces and densities couldn’t be more different, yet the shapes that emerge are amazingly similar.


And yes, these are all terms used in papers published by Caplan and his team. One paper even makes reference to “nuclear waffles,” which are like lasagna with holes.2

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Scientists find a new way to see inside black holes

Scientists find a new way to see inside black holes | Amazing Science |

Scientists at Towson University and the Johns Hopkins University are reporting a new way to peer through the event horizons around black holes and visualize what lies beneath.



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Hydrogen signal from 5 billion light years distant galaxy detected

Hydrogen signal from 5 billion light years distant galaxy detected | Amazing Science |
A faint signal of hydrogen has been detected from a galaxy more than five billion light years away in a discovery that will push the boundaries of astronomy forward, a Perth-based radio astronomer says.


The detection of a faint signal of hydrogen from a galaxy more than five billion light years away will push the boundaries of astronomy forward, a Perth-based radio astronomer says.

Dr Attila Popping, from the University of Western Australia, is part of the International Centre for Radio Astronomy Research (ICRAR) team, which made the discovery.


The team analysed data collected by the Karl G Jansky Very Large Array (VLA) telescope in the US state of New Mexico, and observed emissions from a distant galaxy that would have contained billions of large stars surrounded by clouds of hydrogen gas.


The five-billion-light-year distance is almost double that of the previous record for the detection of neutral hydrogen (HI).

Dr Popping said the find would assist scientists in understanding the evolution of galaxies.


"Hydrogen is the basic element in the universe. That's where everything had to start," he said. "It's the first building block of gas and stars and galaxies. So with the survey we tried to understand the evolution of HI. How it evolves over time.


"By being able to look back over time, and look far away, we can get an image of the universe as it was - five billion years ago in this case - and try to understand how HI evolves and how this affects galaxy formation in general. "What triggers star formation and those sort of things."


He said the discovery was like looking into the past, with the hydrogen long since expired. "The hydrogen has probably been turned into stars," he said. "It's been eaten by the galaxy and become a supernova explosion and expelled again. The gas itself is probably in a different state now, than as we can see it."

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Universe’s first life might have been born on diamond planets

Universe’s first life might have been born on diamond planets | Amazing Science |

“This work shows that even stars with a tiny fraction of the carbon in our solar system can host planets,” says lead author and Harvard University graduate student Natalie Mashian. “We have good reason to believe that alien life will be carbon-based, like life on Earth, so this also bodes well for the possibility of life in the early universe.”

The primordial universe consisted mostly of hydrogen and helium, and lacked chemical elements like carbon and oxygen necessary for life as we know it. Only after the first stars exploded as supernovae and seeded the second generation did planet formation and life become possible.

Clues to how life got started in the universe

Mashian and her PhD thesis advisor Avi Loeb examined a particular class of old stars known as carbon-enhanced metal-poor (CEMP) stars. These “anemic” stars contain only one hundred-thousandth as much iron as our Sun, meaning they formed before interstellar space had been widely seeded with heavy elements.

“These stars are fossils from the young universe,” explains Loeb. “By studying them, we can look at how planets, and possibly life in the universe, got started.”

CEMP stars have more carbon than would be expected, given their age. This relative abundance would influence planet formation as fluffy carbon dust grains (from supernovae) clump together to form tar-black worlds.

From a distance, these carbon planets would be difficult to tell apart from more Earth-like worlds. Their masses and physical sizes would be similar. Astronomers would have to examine their atmospheres for signs of their true nature. Gases like carbon monoxide and methane would envelop these unusual worlds.
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Reproducing the large-scale Universe

Reproducing the large-scale Universe | Amazing Science |

The distribution of galaxies on very large scales encodes valuable information about the origin and fate of the Universe. To study this, the Baryon Oscillation Spectroscopic Survey (BOSS), a branch of the Sloan Digital Sky Survey (SDSS-III), has measured the redshift distribution of galaxies with unprecedented accuracy. One important question arises in the analysis of the data provided by such surveys: if the Universe is comparable to a huge unique experiment, how can we determine the uncertainties in the measurement of quantities derived from observing it?


While common experiments can be repeated an arbitrary number of times in the laboratory, the cosmic Universe is only reproducible in super-computing facilities. One needs to consider the statistical fluctuations caused by the so-called cosmic variance, having its origin in the primordial seed fluctuations. However, reconstructing the large-scale structure covering the volumes of a survey like BOSS from the fluctuations generated after the Big Bang until the formation of the observed galaxies after about 14 billion years of cosmic evolution is an extremely expensive task, requiring millions of super-computing hours.


Francisco Kitaura from the Leibniz Institute for Astrophysics Potsdam (AIP) states: "We have developed the necessary techniques to generate thousands of simulated galaxy catalogues, reproducing the statistical properties of the observations."


The production of the catalogues followed three steps: first, thousands of Dark Matter fields were generated with different seed perturbations at different cosmic epochs. Second, the galaxies were distributed in a nonlinear, stochastic way matching the statistical properties of the observations. Third, the mass of each galaxy – determined by its environment – was reconstructed. Finally, the catalogues of different cosmic times were combined into light cones reproducing the observational properties of the BOSS data, such as the survey geometry, and galaxy number density at different distances and lookback times.


Chia-Hsun Chuang from the AIP explains: "With this novel approach we are able to reliably constrain the errors to the cosmological parameters we extract from the data".

"The MareNostrum super-computing facility at the Barcelona Supercomputing Center (BSC) was used to produce the largest number of synthetic galaxy catalogues to date covering a volume more than ten times larger than the sum of all the large volume simulations carried out so far", reports Gustavo Yepes from the Autonomous University of Madrid (UAM).

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Physicists Suggest Link Between Dark Energy and the Arrow of Time

Physicists Suggest Link Between Dark Energy and the Arrow of Time | Amazing Science |

Is dark energy the reason time moves forward? For years, physicists have attempted to explain dark energy - a mysterious influence that pushes space apart faster than gravity can pull the things in it together. But physics isn’t always about figuring out what things are. A lot of it is figuring out what things cause. In a recent paper, a group of physicists asked this very question about dark energy, and found that in some cases, it might cause time to go forward.

When you throw a ball into the air, it starts with some initial speed-up, but then it slows as Earth’s gravity pulls it down. If you throw it fast enough (about 11 km per second, for those who want to try), it’ll never slow down enough to turn around and start falling back towards you, but it’ll still move more slowly as it moves away from you, because of Earth’s gravity.

Physicists and astronomers in the 1990s expected something similar to have occurred after the big bang - an event that threw matter out in all directions. The collective gravity from all that matter should have slowed it all down, just like the Earth slows down the ball. But that’s not what they found.

Instead, everything seems to have sped up. There’s something pervading the Universe that physically spreads space apart faster than gravity can pull things together. The effect is small - it’s only noticeable when you look at far-away galaxies - but it’s there. It’s become known as dark energy - "dark", because no one knows what it is.

Science is nothing if not the process of humans looking for things they can’t explain, so this isn’t the first time the Universe has stumped us. For centuries, one of those stumpers has been time itself: Why does time have an arrow pointing from the past to the present to the future?

It might seem like a silly question - I mean, if time didn’t go forward, then effects would precede causes, and that seems like it should be impossible - but it’s less of one than you might think.

The Universe, as far as we can tell, only operates according to laws of physics. And just about all of the laws of physics that we know are completely time-reversible, meaning that the things they cause look exactly the same whether time runs forward or backward.

One example is the path of a planet going around a star, which is governed by gravity. Whether time runs forward or backward, planetary orbits follow the exact same paths. The only difference is the direction of the orbit.

But one important piece of physics isn’t time-reversible, and that’s the second law of thermodynamics. It states that as time moves forward, the amount of disorder in the Universe will always increase. Just like dark energy, it’s something we’ve noticed about the Universe, and it’s something that we still don’t totally understand - though admittedly we have a better idea of it than we do of dark energy.

Physicists have, for this reason, reluctantly settled on the second law as the source of time’s arrow: disorder always has to increase after something happens, which requires that time can only move in one direction.

So physicists A. E. Allahverdyan from the Yerevan Physics Institute and V. G. Gurzadyan from Yerevan State University, both in Armenia, decided to see if - at least in a limited situation - dark energy and the second law might be related. To test it, they looked at the simple case of something like a planet orbiting a star with a changing mass.

They found that if dark energy either doesn’t exist or if it pulls space together, the planet just dully orbits the star without anything interesting happening. There’s no way to tell an orbit going forward in time from one going backward in time.

But if dark energy pushes space apart, like it does in our Universe, the planet eventually gets thrown away from the star on a path of no return. This gives us a distinction between the past and the future: run time one way, and the planet is flung off, run it the other way, and the planet comes in and gets captured by the star.

Dark energy naturally leads to an arrow of time. The authors stress that this is a really limited situation, and they’re certainly not claiming dark energy is the reason time only ever moves forward. But they’ve shown a possible link between thermodynamics and dark energy that could help us to understand either - or maybe both - better than we ever have.

The research has been published in Physical Review E.

Via Kim Frye, Tania Gammage, ThePlanetaryArchives/San Francisco CA, CineversityTV
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Gravitational Waves to Crack Neutron Star Mystery

Gravitational Waves to Crack Neutron Star Mystery | Amazing Science |

We are now in an incredible new era of astronomy where the faint ripples in spacetime caused by distant black hole collisions are being detected and studied. These are the most energetic events in the cosmos and, by "listening in" to their gravitational wave signals, these black hole mergers have finally been directly observed.


Although the first detections of gravitational waves by the Laser Interferometer Gravitational-wave Observatory (LIGO) have, so far, been exclusive to the collisions of black holes, astrophysicists have far loftier goals. The next step will be to detect the collisions of neutron stars and, hopefully, use their gravitational wave signals to crack open the super-dense husks of stellar matter, revealing what they are really made of.


Gravitational waves traveling through spacetime can be imagined as ripples traveling across the surface of a pond. And, like those water ripples, gravitational waves carry energy away from massive objects that accelerate, collide or explode. The historic Feb. 11 announcement of the detection of gravitational waves that were recorded by LIGO on Sept. 14, 2015, revealed the first direct observation of two black holes, one 29 solar masses and another 36 solar masses, colliding and merging as one.

Then, on June 14, a second detection was announced, revealing yet another black hole merger. Only this time the black holes were smaller, "weighing in" at 14 solar masses and 8 solar masses.

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Stacking Dolls in Space: Concentric Bubbles Seen Around Star Cluster

Stacking Dolls in Space: Concentric Bubbles Seen Around Star Cluster | Amazing Science |

A young star cluster surrounded by three concentric bubbles was recently found near the M33 galaxy, revealing a cosmic splendor that could be compared to Russian matryoshka nesting dolls.


The concentric bubbles, which comprise what researchers call a triple-bubble, are actually three supernova remnants, shells of gas and dust that form following the explosion of a star. This is the first known case of three supernova remnants nesting one inside the other, said the researchers from the Institute of Astrophysics of the Canary Islands (IAC), who made the discovery. The above illustration shows what a cross section of the three rings might look like if scientists could get a closer look.


The shells provide a unique opportunity to study the remains of these stellar explosions, as well as the the interstellar medium, which is the gas and dust that lies between stars, John Beckman, co-author of the new study, said in a news release. Beckman is an astrophysicist with the Spanish National Resource Council and IAC. "We can measure how much matter there is in a shell, approximately a couple of hundred times the mass of the sun in each of the shells," he said.


Supernova Explosion Seen in Nearby Galaxy (Video)

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X-ray studies could help make LIGO gravitational wave detector 10 times more sensitive

X-ray studies could help make LIGO gravitational wave detector 10 times more sensitive | Amazing Science |
Scientists from Stanford University and the Department of Energy's SLAC National Accelerator Laboratory are using powerful X-rays to study high-performance mirror coatings that could help make the LIGO gravitational wave observatory 10 times more sensitive to cosmic events that ripple space-time.

The current version of the Laser Interferometer Gravitational-Wave Observatory, called Advanced LIGO, was the first experiment to directly observe gravitational waves, which were predicted by Albert Einstein 100 years ago. In September 2015, it detected a signal coming from two black holes, each about 30 times heavier than the sun, which merged into a single black hole 1.3 billion years ago. The experiment picked up a similar second event in December 2015.

"The detection of gravitational waves will fundamentally change our understanding of the universe in years to come," says Riccardo Bassiri, a physical science research associate at Stanford's interdisciplinary Ginzton Laboratory. "Extremely precise mirrors are the heart of LIGO, and their coatings determine the experiment's sensitivity, or ability to measure gravitational waves. So improving those coatings will make future generations of the experiment even more powerful."

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Physicists just showed that the Big Bang might have been a 'Big Bounce'

Physicists just showed that the Big Bang might have been a 'Big Bounce' | Amazing Science |

How did the universe come into existence, a Big Bang or a Big Bounce? In other words, is the reality we currently inhabit brand-new, or is the universe cyclical — inflating and deflating like a balloon over and over again?


In a new study published Wednesday in the Physical Review Letters, a team of international scientists has attempted to answer this eternally vexing question. The paper, titled “Perfect Quantum Cosmological Bounce,” argues that the cosmos we exist in may have been formed from an older collapsing universe.


Although the Big Bounce idea has been around, in one form or the other, since 1922, scientists have faced a key obstacle in explaining how the universe transitions from a contracting to an expanding phase and avoids becoming an “infinite point” in the process. The problem is something that also plagues cosmological models that describe the Big Bang — how does the universe, and everything in it, emerge from a singularity, which, by definition, is a single point that occupies no space at all.


“This is a problem,” co-author Neil Turok, director of the Perimeter Institute for Theoretical Physics in Canada, said in a statement. “The standard cosmology begins with an impossibility.” The present-day universe obeys two seemingly incompatible laws — with quantum mechanics governing the behavior of subatomic particles and relativity describing how clumps of atoms — humans, stars and galaxies — behave. Formulating an all-encompassing Theory of Everything, one that resolves the apparent contradictions between quantum mechanics and relativity has, for the longest time, been the holy grail of particle physics.


The study, which, among other things, attempts to resolve this seemingly insurmountable problem, states that the universe, in its earliest stages, would have exhibited a phenomenon known as conformal symmetry — wherein physical laws governing the entire universe would also have worked at the scale of subatomic particles.


If this is true, the researchers argue, the exact moment of the “bounce” from contraction and expansion can be explained using well-established mathematical model that describes quantum tunneling — a phenomenon in which a particle tunnels through a barrier it cannot cross. According to the researchers, the universe achieved (and will achieve) this transition by approaching the singularity point and then skipping over it by temporarily accessing another dimension.

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New study predicts a universe crowded with black holes















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Scientists Continue to Observe Ancient Celestial Events Using Gravitational Waves

Scientists Continue to Observe Ancient Celestial Events Using Gravitational Waves | Amazing Science |
This new window to the cosmos will be used for centuries and this is just the beginning of a new era of scientific discovery.


At the LIGO facility in Livingston, Louisiana, a distortion was detected at 7:38 PM Pacific time on the night of December 25th and then detected by the twin facility in Hanford, Washington just 1.1 milliseconds later. The information gathered from the telltale waves lead scientists to believe that they were produced in the final moments of the violent merger of two black holes that danced around each other’s orbit almost 27 times before finally colliding. The doomed black holes are thought to be 14 and 8 times the mass of our Sun and when the dust settled from the collision, a single, gargantuan black hole remained measuring about 21 times the mass of the Sun.


“This is a very important discovery,” said University of Illinois astrophysicist Stuart Shapiro. “It cements the reality of the first detection and makes credible the belief that detections of this sort will be common and that we have truly opened up a new window to the Universe.”


When it comes to observing the known universe, humanity’s first window was optical astronomy and today it’s newest, gravitational wave astronomy, will widen that window and allow humanity to explore the origins of the cosmos. “When Galileo first trained his optic telescope on the heavens and opened up modern optical astronomy, that was the first of the electromagnetic windows out of the universe: light. We use the phrase ‘window’ to mean certain technologies we use to look for radiation with a certain wavelength region,” explained Theoretical Astrophysicist Kip Thorne to the Observer.


“In the 1940’s, radio astronomy was born—looking with radio waves instead of light. In the 1960’s, X-ray astronomy was born. In the 1970’s, gamma-ray astronomy was born. Infrared astronomy was also born in the 1960’s. Soon we had all these different windows that all looked with electromagnetic waves but with different wavelengths. The universe looks very different through a radio telescope and an x-ray telescope than it does with light. The same thing is happening with gravitational wave astronomy.”


Dr. Kip Thorne believes this new window to the cosmos will be used for centuries just as optical astronomy has and that this is just the beginning of a new era of scientific discovery. “We’ll have four different gravitational wave windows open within the next 20 years and each of them will see something different. We’ll be probing the birth of the universe with this, the so-called ‘inflationary era’ of the universe,” explained Thorne. “We’ll be probing the birth of the fundamental forces and how they came into being. We’ll watch them be born in the earliest moments of the universe using gravitational waves. We will watch black holes collide which we are now doing—but huge black holes collide. We’ll  watch stars be torn apart by black holes.”

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Dark Matter May Be Made of Primordial Black Holes

Dark Matter May Be Made of Primordial Black Holes | Amazing Science |
Astronomers are beginning to find strong links between dark matter and primordial black holes.


Could dark matter — the elusive substance that composes most of the material universe — be made of black holes? Some astronomers are beginning to think this tantalizing possibility is more and more likely.  Alexander Kashlinsky, an astronomer at the NASA Goddard Space Flight Center in Maryland, thinks that black holes that formed soon after the Big Bang can perfectly explain the observations of gravitational waves, or ripples in space-time, made by the Laser Interferometer Gravitational-Wave Observatory (LIGO) last year, as well as previous observations of the early universe.


If Kashlinsky is correct, then dark matter might be composed of these primordial black holes, all galaxies might be embedded within a vast sphere of black holes, and the early universe might have evolved differently than scientists had thought.

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'Wasteful' galaxies launch heavy elements into surrounding halos and deep space | Amazing Science |



The research, which was recently published online in the Monthly Notices of the Royal Astronomical Society, shows that more oxygen, carbon and iron atoms exist in the sprawling, gaseous halos outside of galaxies than exist within the galaxies themselves, leaving the galaxies deprived of raw materials needed to build stars and planets.


"Previously, we thought that these heavier elements would be recycled in to future generations of stars and contribute to building planetary systems," said Benjamin Oppenheimer, a research associate in the Center for Astrophysics & Space Astronomy (CASA) at CU-Boulder and lead author of the study. "As it turns out, galaxies aren't very good at recycling."


The near-invisible reservoir of gas that surrounds a galaxy, known as the circumgalactic medium (CGM), is thought to play a central role in cycling elements in and out of the galaxy, but the exact mechanisms of this relationship remain elusive. A typical galaxy ranges in size from 30,000 to 100,000 light years while the CGM can span up to a million light years.


The researchers used data from the Cosmic Origin Spectrograph (COS), a $70 million instrument designed at CU-Boulder and built by Boulder, Colorado-based Ball Aerospace Technology Corp., to study the composition of the CGM.


COS is installed on NASA's Hubble Space Telescope and uses ultraviolet spectroscopy to study the evolution of the universe.

Spiral galaxies like the Milky Way actively form stars and have a blueish color while elliptical galaxies have little star formation and appear red. Both types of galaxies contain tens to hundreds of billions of stars that create heavy elements.

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Hubble finds universe may be expanding faster than expected

Hubble finds universe may be expanding faster than expected | Amazing Science |

Astronomers using NASA's Hubble Space Telescope have discovered that the universe is expanding 5 percent to 9 percent faster than expected. "This surprising finding may be an important clue to understanding those mysterious parts of the universe that make up 95 percent of everything and don't emit light, such as dark energy, dark matter, and dark radiation," said study leader and Nobel Laureate Adam Riess of the Space Telescope Science Institute and The Johns Hopkins University, both in Baltimore, Maryland. The results will appear in an upcoming issue of The Astrophysical Journal.


Riess' team made the discovery by refining the universe's current expansion rate to unprecedented accuracy, reducing the uncertainty to only 2.4 percent. The team made the refinements by developing innovative techniques that improved the precision of distance measurements to faraway galaxies.


The team looked for galaxies containing both Cepheid stars and Type Ia supernovae. Cepheid stars pulsate at rates that correspond to their true brightness, which can be compared with their apparent brightness as seen from Earth to accurately determine their distance. Type Ia supernovae, another commonly used cosmic yardstick, are exploding stars that flare with the same brightness and are brilliant enough to be seen from relatively longer distances.




The team compared those distances with the expansion of space as measured by the stretching of light from receding galaxies. The team used these two values to calculate how fast the universe expands with time, or the Hubble constant.

The improved Hubble constant value is 73.2 kilometers per second per megaparsec. A megaparsec equals 3.26 million light-years. The new value means the distance between cosmic objects will double in another 9.8 billion years.


This refined calibration presents a puzzle, however, because it does not quite match the expansion rate predicted for the universe from its trajectory seen shortly after the big bang. Measurements of the afterglow from the big bang by NASA's Wilkinson Microwave Anisotropy Probe (WMAP) and the European Space Agency's Planck satellite mission yield predictions for the Hubble constant that are 5 percent and 9 percent smaller, respectively.

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The Most Amazing Galaxies In The Universe

The Most Amazing Galaxies In The Universe | Amazing Science |


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Scientists discover how supermassive black holes keep galaxies turned off

Scientists discover how supermassive black holes keep galaxies turned off | Amazing Science |
An international team of scientists has identified a common phenomenon in galaxies that could explain why huge numbers of them turn into cosmic graveyards.


Galaxies begin their existence as lively and colourful spiral galaxies, full of gas and dust, and actively forming bright new stars. However, as galaxies evolve, they quench their star formation and turn into featureless deserts, devoid of fresh new stars, and generally remain as such for the rest of their evolution. But the mechanism that produces this dramatic transformation and keeps galaxies turned off, is one of the biggest unsolved mysteries in galaxy evolution.


Now, thanks to the new large SDSS-IV MaNGA survey of galaxies, a collaborative effort led by the University of Tokyo and involving the University of Oxford has discovered a surprisingly common new phenomenon in galaxies, dubbed "red geysers", that could explain how the process works.


Researchers interpret the red geysers as galaxies hosting low-energy supermassive black holes which drive intense interstellar winds. These winds suppress star formation by heating up the ambient gas found in galaxies and preventing it to cool and condense into stars.


The research will be published in the journal Nature. Lead author Dr Edmond Cheung, from the University of Tokyo's Kavli Institute for the Physics and Mathematics of the Universe, said: 'Stars form from the gas, but in many galaxies stars were found not to form despite an abundance of gas. It was like having deserts in densely clouded regions. We knew quiescent galaxies needed some way to suppress star formation, and now we think the red geysers phenomenon may represent how typical quiescent galaxies maintain their quiescence.'


'Stars form from the gas, a bit like the drops of rain condense from the water vapour. And in both cases one needs the gas to cool down, for condensation to occur. But we could not understand what was preventing this cooling from happening in many galaxies,' said Co-author Dr Michele Cappellari, from the Department of Physics at Oxford University. 'But when we modelled the motion of the gas in the red geysers, we found that the gas was being pushed away from the galaxy centre, and escaping the galaxy gravitational pull.'


'The discovery was made possible by the amazing power of the ongoing MaNGA galaxy survey' said Dr Kevin Bundy, from the University of Tokyo, the overall leader of the collaboration. 'The survey allows us to observe galaxies in three dimensions, by mapping not only how they appear on the sky, but also how their stars and gas move inside them.'


Using a near-dormant distant galaxy named Akira as a prototypical example, the researchers describe how the wind's driving mechanism is likely to originate in Akira's galactic nucleus. The energy input from this nucleus, powered by a supermassive black hole, is capable of producing the wind, which itself contains enough mechanical energy to heat ambient, cooler gas in the galaxy and thus suppress star formation.

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