Ever wonder how many black holes are nearby? Well, NASA has gone and counted them for you. According to data gathered by NASA’s Swift satellite, there are about 200 supermassive black holes within about 400 million light-years of the Earth. Swift’s first job is to scan the skies for gamma ray bursts, but during downtime, the spacecraft hunts for objects that emit X-rays. And supermassive black holes are one of the most powerful sources of X-rays out there.
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Black Hole Stops Star Formation in Elliptical Galaxy
New images from NASA’s Chandra X-Ray Observatory show the environment around the supermassive black hole at the heart of M87, a nearby giant elliptical galaxy. Chandra detected loops and rings in the hot gas that surrounds the galaxy. These loops are evidence of periodic eruptions near the supermassive black hole, which send shockwaves through the surrounding gas. These outbursts happen every few million years, and prevent the gas in the cluster from cooling to create stars.
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Finding All the Black Holes
Black holes might be invisible, but the superheated matter piling up around them shines brightly in the gamma ray spectrum. Most of these black holes are so far away, their gamma rays look like a diffuse background radiation that covers the sky. ESA’s Integral spacecraft recently calibrated the level of this background radiation by watching a point of sky, and let the Earth pass in front of it, to slowly block it out. Using these calculations, astronomers will be better able to distinguish point sources of gamma rays from the wash of background radiation.
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Fine Tuning the Search for Black Holes
Although black holes can’t be seen directly, they’re relatively easy to find. Matter spiraling into a black hole becomes superheated, shines brightly, and is visible across the Universe. A new supercomputer simulation has fine tuned the energy calculations for atoms in the vicinity of a black hole. This is very important, because astronomers working on black holes will base their assumptions on these atomic data. The new calculations bring the potential error rates down to a few percent, enhancing the accuracy of other research.
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Supermassive Black Holes Prevent Star Formation
The supermassive black holes thought to be lurking at the heart of most galaxies could create such a hostile environment around them that they prevent the formation of new stars. This is according to new research assisted by NASA’s Galaxy Evolution Explorer (GALEX). The space-based telescope observed more than 800 galaxies, and found that the larger galaxies had fewer young stars. Astronomers believe that jets blasting out of supermassive black holes could clear out gas and dust; potential star forming material.
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The Search for Hidden Black Holes
Look into the sky with X-ray instruments, and you’ll see a background radiation in all directions. Astronomers think these X-rays are produced by the supermassive black holes at the centres of most galaxies. But astronomers can’t find these black holes, which should be bright in the most energetic range of the electromagnetic spectrum. Maybe they’re hiding; shrouded in thick clouds of gas and dust. Or maybe something else is generating all the X-ray background radiation.
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A New View of Quasars
Some of the brightest objects in the Universe are quasars. A mystery for decades, most astronomers now believe quasars are the bright centres of galaxies with actively feeding supermassive black holes. A team of researchers have found evidence that there might be something very different at the heart of these galaxies to cause quasars. Instead of black holes consuming matter, there could be objects with powerful magnetic fields that act like propellers, churning matter back into the galaxy.
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Magnetic Fields Help Black Holes Pull In Matter
Even though the gravity from black holes is so strong that light can’t even escape, we can see the radiation from the superheated matter that’s about to be consumed. Until now, scientists haven’t been able to explain how all this matter continuously falls into the black hole – it should just orbit, like planets going around a star. New data from the Chandra X-Ray Observatory shows that a black hole’s powerful magnetic field creates a turbulence in surrounding matter that helps drive it inward to be consumed.
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Everything’s on the Menu for Supermassive Black Holes
The supermassive black holes that lurk at the heart of most galaxies have enormous appetites. They’ve already consumed millions of times the mass of our own Sun, and they’re not done yet. Everything’s on the menu: mostly gas, dust, planets and stars, but the occasional exotic delicacy gets consumed too. “Compact objects”, such as stellar mass black holes, neutron stars, and white dwarfs occasionally fall into their grasp too. But these objects don’t go with a whimper; they make screams we’ll soon hear across intergalactic space.
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Podcast: Dark Energy Stars
Black holes… you know. Cosmic singularities that can contain the mass of billions of stars like our Sun. Where the pull of gravity is so strong, nothing, not even light can escape their fearsome grasp. They’re the source of much discussion, indirect observation and science fiction speculation. But according to George Chapline from Lawrence Livermore National Laboratory in California, they don’t exist. Instead we have dark energy stars, which are connected to that mysterious force accelerating the expansion of the Universe.
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