Astronomers have deciphered the dynamics of yet another great trick that monster black holes can play.
In many galaxies, jets of energy are squeezed outward by the black hole that lurks at the center, and go shooting off in opposite directions into space.
But in a few bizarre-looking galaxies, the jets take the form of four beams in the shape of an X. Now, radio astronomy observations have shown how that happens.
Astronomers have no trouble understanding how black holes — objects so dense that not even light can escape the tombstone grip of their gravity — can become the most luminous objects in the universe, powering quasars. The pressure in the fat, fiery swirl of doom that surrounds a black hole expels high-energy particles from the top and bottom of the doughnut.
Other things to check out:
New Possible Explanation of Strange Black Hole Merger Revealed
In addition, the discovery paper (released in Australia on April 19, 2020) reported that at least one of the merging black holes had to be spinning: rotating around its axis. However, gravitational waves do not allow accurate measurement of individual spins. Only a specific spin combination can be measured. Therefore, to infer individual spins, assumptions must be made based on scientific models.
Within 24 hours of the discovery’s announcement, OzGrav Chief Investigator Ilya Mandel, from Monash University, and collaborator Tassos Fragos, from the University of Geneva, wrote a follow-up paper which has just been accepted by Astrophysical Journal Letters.
The Mystery of a Strange X-Galaxy Powered by a Monster Black Hole Is Finally Solved
A team of US and South African researchers has published highly detailed images of the largest X-shaped "radio galaxy" ever discovered – PKS 2014-55.
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The spectacular new images were taken using the 64-antenna MeerKAT telescope in South Africa, by an international research team led by Bill Cotton of the US National Radio Astronomy Observatory.
Our research team also took detailed images of galaxy PKS 2014-55 last year, as part of the Evolutionary Map of the Universe project led by astrophysicist Ray Norris . We used CSIRO's Australian Square Kilometre Array Pathfinder (ASKAP) telescope in Western Australia, which just completed its first set of pilot astronomical surveys.
Nearest-Known Black Hole Discovered, Inviting Refresher on Black Holes
According to NPR, the black hole was found by astronomers at the European Southern Observatory. “They found it hiding in a double-star system known as HR 6819, where scientists say the black hole—rendered effectively invisible by gravity so strong that even light cannot escape—revealed itself in the curious orbit of the star nearer the center of the system,” the article said.
“The black hole is not anywhere near close enough for the average observer on Earth to feel its effects. But it is close enough that, during winter in the Southern Hemisphere, the two stars that are believed to compose its solar system can be seen without a telescope as a single point of light in the constellation Telescopium.”
And here's another article:
Three Million Light-Year Long Bridge Between Two Galaxy Clusters Warped by Supermassive Black Hole
A composite view of the Abell 2384 system, comprising two galaxy clusters located 1.2 billion light years from Earth.
Galaxy clusters are the largest objects in the Universe held together by gravity. They contain hundreds or thousands of galaxies, vast amounts of multi-million-degree gas that shines brightly in X-rays, and enormous reservoirs of unseen dark matter.
The system portrayed in these images, called Abell 2384, is located 1.2 billion light years from Earth and comprises an overall mass of over 260 trillion times the mass of the Sun. In this case, the two galaxy clusters collided and then passed through each other, releasing a flood of hot gas from each cluster that formed an unusual bridge between the two objects.
A small black hole at a small distance | Deccan Herald
Right from the day the word 'black hole' was coined, people have been looking at the cosmic phenomenon as a mysterious monster, just waiting to swallow everything near it. Science fiction movies and books also created an atmosphere of fear. The relief, however, came when we took a closer look at the numbers, the mass, the distance - all running to nine or ten digits. Then there were estimates about how close a black hole should be for us to really worry about it. The answer: thirty light
And we now know there are no such "monsters" within this distance, near the earth. This also implies that there are no black holes at a "respectable" distance to be seen by a common person, or even astronomers and theoreticians.
The Closest Black Hole Is 1,000 Light-Years Away - Eos
Supermassive black holes—millions or even billions of times more massive than the Sun—anchor the centers of most galaxies. But smaller black holes, at just a few solar masses, should theoretically pepper galaxies in droves. A few hundred candidates have been found in the Milky Way. Now researchers have spotted another one of these stellar mass black holes, and it holds a special honor: It's the closest black hole to Earth yet discovered.
It's much harder to spot the many black holes that aren't consuming matter—they don't produce X-rays. But sometimes the universe aligns itself just right to reveal these wallflower black holes. That's what Rivinius and his collaborators found when they examined HR 6819, a seemingly ordinary pair of stars about 1,000 light-years away in the constellation Telescopium.
This Star Survived Being Swallowed by a Black Hole | HowStuffWorks
If you get into a cage match with a black hole , well, it won't be pretty. That's one of the universe's defining traits – black holes have such an immense gravitational pull that they can swallow stars whole. Except, one lucky star managed to escape a black hole's wrath, at least for a moment.
Still, the black hole's immense mass (about 400,000 times that of our sun) and gravitational pull has caused the star to be stuck in an elliptical orbit around it. Originally a red giant, the star's hydrogen-rich outer layers have been stripped by the black hole, leaving just a helium-rich core (called a white dwarf ). It orbits the black hole once every nine hours, and as pieces are stripped away, they blend with other material circling the black hole.
Happening on Twitter
🔭This infrared image of the center of our Milky Way galaxy reveals dense swirls of dust and gas. ⭐️Scientists are… https://t.co/etktkCGu49 SOFIAtelescope (from California) Wed May 13 17:42:58 +0000 2020
On this day in 1994, 'Black Hole Sun' is released as the second single off Soundgarden's album 'Superunknown'. https://t.co/BEhS1e2ntC MonstersOfRock (from Los Angeles, CA) Wed May 13 12:21:54 +0000 2020
NASA's New Black Hole Visualization Is Straight out of INTERSTELLAR https://t.co/HI1LBJafMf nerdist Fri May 15 01:58:56 +0000 2020
The dust-shrouded objects may be binary stars merging as they orbit the supermassive black hole in our galaxy's cor… https://t.co/BqAUvmPfVW AstronomyMag (from Our tiny corner of the cosmos) Thu May 14 17:04:07 +0000 2020
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