2023-05-09 21:59:44
I’m not usually very good with dates but if someone asked me what I was doing on April 10, 2019… then I would remember. Like all lovers of astronomy and science, that day I was glued to the computer screen to attend the presentation of the first real image of a black hole. Until that moment, humanity had theorized for decades regarding its existence, hundreds of indirect evidence had been collected, mass, velocity, and event horizon data had been analyzed, thousands of artistic representations had been published… but we had never photographed a real black hole.
Then came the great EHT (Event Horizon Telescope) project, a fruitful international collaboration made up of eight radio telescopes spread around the world that, thanks to the interferometryit becomes a gigantic peephole with a virtual size of the Earth itself. This is how the famous photograph of the black hole in the center of Messier 87 arrived, a vast galaxy located in the Virgo cluster. Located 55 million light-years from us, that colossal black hole M87* shone like a ring in Tolkien’s novels, with a mass of 6,500 suns.
However, and although this 2019 image has gone down in history, many questions still remained in the air, especially since it does not show traces of the jets of matter that should accompany a black hole. In that image, the EHT radio telescopes were not operating at an adequate wavelength to capture them, they were need to decrease the frequency (and therefore increase the wavelength) to be able to visualize them (3.5 mm instead of 1.3 mm).
A little over three years have passed since the EHT inaugurated the direct observation of black holes through interferometry and, just a few days ago, has finally been published in Nature an image showing the long-awaited relativistic jet of M87. It has been laborious and patient work (the observations used were made between April 14 and 15, 2018) and it has taken a new great collaboration to get here. this time the data comes from various radio telescope projects around the world that include the GMVA (Global Millimetre VLBI Array), ALMA (Atacama Large Millimeter/submillimeter Array) and the GLT (GreenLand Telescope).
The published image clearly shows the connection between the supermassive black hole M87*, its ring of light and the famous high-speed jet… and it comes with a surprisebecause in it are observed “three arcs associated with the beginning of the relativistic jet, a central spine that emerges from the ring and two border arcs above and below”.
What are these “jets” that shoot out of black holes?
“The matter that falls in a spiral towards the black hole forms the so-called matter accretion disk,” explains the physicist, mathematician and well-known popularizer to Yahoo. Francis Villatoro. “This matter accelerates and gains a lot of energy, with which its atoms separate into their nuclei and their electrons, giving rise to a plasma. Both nuclei and electrons are electrically charged, so they behave like electrons in an electrical wire and generate a magnetic field. These magnetic field lines in the disk are closed, they form “horseshoes” that go out of the disk and return to it (this also happens on the surface of the Sun). But the lines near the inner edge of the disk cannot be closed and remain as open lines leading toward the black hole’s event horizon. When the black hole rotates very fast, the empty space between the horizon and the disk also rotates; the open lines of the magnetic field are forced to rotate in a spiral, escaping upwards (perpendicular to the disk) without reaching the horizon. These magnetic field lines drag the plasma from the disk and shoot it out producing the relativistic jet of matter.”
As is often the case when trying to understand the Cosmos, there are still many unanswered questions, but the amount of knowledge we are gaining from studying a single black hole is fascinating. The great M87* has become the greatest source of discoveries in black hole physics, and observation using interferometry has revealed itself as a marvelous technique for studying one of the most exciting phenomena in the Universe.
More fascinating articles and news regarding the Universe on Yahoo:
Scientific references and more information:
Lu, Ru-Sen, et al. «A Ring-like Accretion Structure in M87 Connecting Its Black Hole and Jet“. Nature, (April 2023) DOI:10.1038/s41586-023-05843-w.
Castelvecchi, David. «Black-Hole Image Reveals Details of Turmoil around the Abyss“. Nature, (April 2023) DOI:10.1038/d41586-023-01442-x.
Francis R. Villatoro “The long-awaited image of the nexus between the black hole M87* and its relativistic jet” EmuleNews, Naukas
YOU MAY ALSO BE INTERESTED IN | ON VIDEO
NASA creates a habitat with a 3D printer to simulate life on Mars
1683827974
#time #black #hole #jet #matter
