Astrophysics

Molecular oxygen discovered in another galaxy for first time ever

Astronomers have announced a significant discovery: they have found molecular oxygen for the first time ever outside the Solar System. In a research published in The Astrophysical Journal, they noted that it was discovered in the Markarian 231 galaxy, 561 million light-years from Earth. A light-year, which measures distance in space, equals about 6 trillion miles. “This first detection of extragalactic molecular oxygen provides an ideal tool to study AGN-driven molecular outflows on dynamic timescales of tens of megayears,” the researchers wrote in the study’s abstract. The find is significant since the galaxy is powered by a quasar, a highly active supermassive black hole. Some astronomers believe there are two quasars at the center of the galaxy. though that has yet to be proven. Quasars are considered the brightest objects in the universe and the quasar at the center of Markarian 231 is the closest one to Earth. The researchers used the IRAM 30-meter radio telescope in Spain to make their observations after looking at it for four days. It’s unclear what is causing the oxygen to appear, but it may be due to “the interaction between the active galactic nucleus-driven molecular outflow and the outer disc molecular clouds,” the researchers wrote in the study. Oxygen is necessary for life as we know it, according to the University Corporation for Atmospheric Research, but so far, molecular oxygen has been difficult to find. It has been detected in the Orion nebula, but since it experiences intense radiation from the young stars being formed, it’s possible the water ice is split into a molecular level, allowing for the discovery of oxygen. Oxigen is the third most abundant element in the universe, trailing hydrogen and helium. Some scientists believe oxygen in space is stuck with hydrogen in the form of water ice, which could be why it is hard to detect. In November, NASA’s Curiosity rover discovered that oxygen “behaves in a way that so far scientists cannot explain” on Mars. The Curiosity rover, which has been exploring the Gale Crater since it landed on Mars in August 2012, found that the oxygen in the atmosphere did not behave in the same way that nitrogen and argon did, following “a predictable season pattern, waxing and waning in concentration in Gale Crater throughout the year relative to how much CO2 is in the air.” Instead, the amount of oxygen in the air throughout the spring and summer rose by as much as 30 percent, then dropped to levels that were predicted by known chemistry in the fall.

Fascinating!!   🙂

Dark matter ‘bridge’ holding galaxies together has been captured for the first time

The first image of a dark matter “bridge”, believed to form the links between galaxies, has been captured by astrophysicists in Canada. Researchers at the University of Waterloo used a technique known as weak gravitational lensing to create a composite image of the bridge. Gravitational lensing is an effect that causes the images of distant galaxies to warp slightly under the influence of an unseen mass, such as a planet, a black hole, or in this case, dark matter. Their composite image was made up of a combination of combined lensing images taken of more than 23,000 galaxy pairs, spotted 4.5 billion light-years away. This effect was measured from a multi-year sky survey at the Canada-France-Hawaii Telescope. These results show that the dark matter filament bridge is strongest between systems less than 40 million light years apart, and confirms predictions that galaxies across the Universe are tied together through a cosmic web of the elusive substance. Dark matter is a mysterious element said to make up around 84 per cent of the Universe. It’s known as “dark” because it doesn’t shine, absorb or reflect light, which has traditionally made it largely undetectable, except through gravity and gravitational lensing. Evidence for the existence of this form of matter comes, among other things, from the astrophysical observation of galaxies, which rotate far too rapidly to be held together only by the gravitational pull of the visible matter. Astrophysics has long proposed the Universe’s web of stars and galaxies is supported by a “cosmic scaffolding” made up of fine threads of this invisible dark matter.

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Scientists find evidence of gravitational waves predicted by Einstein

After decades of searching, scientists announced Thursday that they have detected gravitational waves — essentially ripples in the fabric of space-time — that had been predicted by Einstein. An international team of astrophysicists said that they detected the waves from the distant crash of two black holes, using a $1.1 billion instrument. The Ligo Collaboration was behind the discovery and it has been accepted for publication in the journal Physical Review Letters. “We have detected gravitational waves,” Caltech’s David H. Reitze, executive director of the LIGO Laboratory, told journalists at a news conference in Washington, DC. “Our observation of gravitational waves accomplishes an ambitious goal set out over five decades ago to directly detect this elusive phenomenon and better understand the universe, and, fittingly, fulfills Einstein’s legacy on the 100th anniversary of his general theory of relativity,” Reitze said in a statement. The news, according to the Associated Press, is being compared by at least one theorist to Galileo taking up a telescope and looking at the planets and the biggest discovery since the discovery of the Higgs particle. It has stunned the world of physics and astronomy, prompting scientists to say it is the beginning of a new era in physics that could lead to scores more astrophysical discoveries and the exploration of the warped side of the universe. “Every year I tell my Gravity class about the three classics successes of General Relativity: the perihelion precession of Mercury, light bending and gravitational redshift. Next year, I’ll be adding a fourth: gravitational waves,” Tony Padilla, Royal Society University Research Fellow in the School of Physics & Astronomy at the University of Nottingham, said in a statement. “Their detection is a stunning triumph for experiment, for theory, and most notably, for Einstein. And the source of these waves is rumored to be a merger of two black holes. Wow! Just wow! Black holes really exist,” he said. “No more arguments. Looking further ahead we can look forward to a whole new era for astronomy, listening out for these remarkable signals that will teach us so much about the fundamental nature of gravity and the Universe. It’s almost as if we have grown a new set of ears, and there could be so much to hear!” The discovery confirms a major prediction of Albert Einstein’s 1915 general theory of relativity. Gravitation waves carry information about their dramatic origins and about the nature of gravity that cannot be obtained from elsewhere. Not only have they fascinated scientists, but found their way into pop culture — namely through movies such as “Back to the Future,” where the space-time continuum was used as a medium for the DeLorean time machine to go back in time. It also was featured in the “Terminator” series. Their existence was first demonstrated in the 1970s and 1980s by Joseph Taylor, Jr., and colleagues. In 1974, Taylor and Russell Hulse discovered a binary system composed of a pulsar in orbit around a neutron star. Taylor and Joel M. Weisberg in 1982 found that the orbit of the pulsar was slowly shrinking over time because of the release of energy in the form of gravitational waves. For discovering the pulsar and showing that it would make possible this particular gravitational wave measurement, Hulse and Taylor were awarded the 1993 Nobel Prize in Physics. In the latest breakthrough, the gravitational waves were detected on Sept. 14, 2015, by both of the twin Laser Interferometer Gravitational-wave Observatory (LIGO) detectors, located in Livingston, La., and Hanford, Wash. Based on the observed signals, LIGO scientists estimate that the black holes for this event were about 29 and 36 times the mass of the sun, and the event took place 1.3 billion years ago. About three times the mass of the Sun was converted into gravitational waves in a fraction of a second — with a peak power output about 50 times that of the whole visible universe. By looking at the time of arrival of the signals — the detector in Livingston recorded the event 7 milliseconds before the detector in Hanford — scientists can say that the source was located in the Southern Hemisphere. According to general relativity, a pair of black holes orbiting around each other lose energy through the emission of gravitational waves, causing them to gradually approach each other over billions of years, and then much more quickly in the final minutes. In a final fraction of a second, the two black holes collide and form one massive black hole. A portion of their combined mass is converted to energy, according to Einstein’s formula E=mc2, and this energy is emitted as a final strong burst of gravitational waves. These are the gravitational waves that LIGO observed. “With this discovery, we humans are embarking on a marvelous new quest: the quest to explore the warped side of the universe — objects and phenomena that are made from warped spacetime. Colliding black holes and gravitational waves are our first beautiful examples,” Caltech’s Kip Thorne said. Others, like David Clements, an astrophysicist at Imperial College London, said the discovery gives the world “a whole new tool with which to look at the universe, allowing us to look at some of the most energetic events imaginable — collisions of black holes and neutron stars — in ways that just were not possible before. We now have a whole new spectrum of radiation with which to study the universe. “It’s as if we were blind and today LIGO has opened our eyes,” he said in a statement.

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