The Most Intimate Portrait But of a Black Gap
Collaborating with Event Horizon Telescope, an international team of radio astronomers that has been staring into the throat of a giant black hole for years, released the most intimate portrait yet of the forces that make quasars, the glowing fountains of energy that spill over the interstellar, on Wednesday and intergalactic space and disrupt the growth of distant galaxies.
The black hole in question is a 6.5 billion times as massive monster as the Sun and lies at the center of a huge elliptical galaxy, Messier 87, about 55 million light years away in the constellation Virgo. Two years ago, the team photographed it and produced the first image of a black hole. the previously invisible being, a porthole for eternity. It looked like a hazy ring of smoke, just as Albert Einstein’s equations had predicted a century ago.
The group has extracted more data over the past two years from their observations on the polarization of radio waves, which can reveal the shape of the magnetic fields in the hot gas swirling around the hole.
Now, seen through the radio equivalent of polarized sunglasses, the M87 black hole appears as a fine vortex, like the spinning fan blades of a jet engine, pumping matter into the black hole and energy out into space.
“It’s like putting on polarized sunglasses on a sunny day – suddenly you can see what’s going on,” said Sheperd Doeleman, an astronomer at the Harvard-Smithsonian Center for Astrophysics and founding director of the collaboration.
“Now we can actually see the patterns of these fields in M87 and examine how the black hole directs material into its center,” he said.
Daniel Holz, an astrophysicist at the University of Chicago who was not involved in the research, said, “These relativistic jets are some of the most extreme phenomena in nature and combine gravity, hot gas and magnetic fields to create a jet that moves a Whole crosses galaxy. It is exciting that EHT is helping us learn more about what is going on at the heart of these relativistic jets that form very close to the “surface” of a black hole. “
Janna Levin, an astrophysicist at Barnard College, Columbia University who studies black holes but was not part of the Event Horizon team, said the results were “exciting” as they revealed details about how a black hole is “deadly, powerful A beam cannon that stretches over thousands of light years can create ‘astronomical’. “
The level of detail in the new image could renew the theorists’ interest in features they had given up on ever being able to observe. “A lot of people will go back to their pretty calculations, just daydreaming in pen and paper, excitedly and nervously asking, ‘Could the EHT actually see this?'” Said Dr. Levin. “I’ll be one of them.”
The results were announced on Wednesday in two papers published in the Astrophysical Journal Letters of the Event Horizon Telescope Collaboration and a third by Ciriaco Goddi of Radboud University in the Netherlands and a large international cast accepted by the same became diary.
Dark demons of the cosmos
Black holes are bottomless pits in spacetime where gravity is so strong that not even light can escape. Whatever occurs essentially disappears from the universe. The cosmos is littered with black holes. Many are dead stars that have catastrophically collapsed. You sit in the center of almost every galaxy and are a million or billion times as massive as any star.
Paradoxically, despite their ability to swallow light, black holes are the most luminous objects in the universe. Material – gas, dust, shredded stars – that falls into a black hole is heated to millions of degrees as it swirls around the doom’s drain in a dense vortex of electromagnetic fields. Most of this matter falls into the black hole, but some, like toothpaste, are pushed out by tremendous pressures and magnetic fields. How all this energy is created and marshaled is unknown to astronomers.
Such fireworks, which can outshine galaxies a thousand times over, can be seen throughout the universe. When they were first observed in the early 1960s, they were called quasars. This discovery prompted physicists and astronomers to initially take seriously the idea that there are black holes.
In 2009, Dr. Doeleman and his colleagues launched the Event Horizon Telescope, an international collaboration in which around 300 astronomers from 13 institutions are currently participating.
The telescope is named for the point where there is no return around a black hole. beyond the event horizon all light and matter is consumed. In April 2017, when the telescope observed M87 for 10 days, it consisted of a network of eight radio observatories around the world – “a telescope the size of the world,” as Dr. Doeleman likes to say that is able to see details as small as orange on the moon. It then took the team two years to process the data. The results came together in April 2019 when Dr. Doeleman and his colleagues presented the first images – actually radio cards – of a black hole, the monster in M87.
Black holes were “collided” for the first time in 2015 by the laser interferometer gravitational wave observatory. Now they could be seen as an ink portal of nothingness, framed by a swirling donut of radiant gas in the center of the galaxy Messier 87.
“We saw what we thought was invisible,” said Dr. Doeleman at the time. The picture appeared on the front page of newspapers around the world, and a copy is now in the permanent collection of the Museum of Modern Art in New York.
But that was just the beginning of the journey inward.
In the dynamo
It took another two years for researchers to create the polarized images released on Wednesday.
Jets and lobes of radio, X-rays, and other forms of energy extend more than 100,000 light years from the black hole in M87. Much of this radiation comes from energetic electrical particles that rotate in magnetic fields.
The reprocessed image allows astronomers to trace these fields back to their origins in a hot, chaotic ring of electrified gas or plasma about 30 billion miles in diameter – four times as wide as Pluto’s orbit. This performance is made possible because the light from the disc is partially polarized and vibrates more in one direction than in another.
“The direction and intensity of the polarization in the picture says something about the magnetic fields near the black hole’s event horizon,” said Andrew Chael, an astrophysicist at Princeton University who is part of the Event Horizon team.
Astronomers have debated for years whether the magnetic fields surrounding so-called low-luminosity black holes like M87 were weak and turbulent or “strong” and coherent. In this case, said Dr. Chael, the magnetic fields are strong enough to disrupt the fall of the gas and transfer energy from the spinning black hole to the beam.
“The EHT images also provide evidence that the bright beam in M87 is actually powered by the black hole’s rotational energy, which twists the magnetic fields as it rotates,” said Michael Johnson, another Event Horizon member of the Harvard-Smithsonian Center for astrophysics.
As a result, Dr. Doeleman: “This gives the emitted radio waves the azimuthal twist” observed in the curvature pattern of the new, polarized images. He noted that an azimuthal phrase would be a “good name for a cocktail”.
A by-product of the work, said Dr. Doeleman, was that astronomers could estimate the rate at which the black hole was feeding on its surroundings. Apparently it’s not particularly hungry; The black hole eats “a meager” thousandth of the solar mass per year.
“Still, launching powerful jets spanning thousands of light years is enough and it’s bright enough to catch with the EHT,” he said.
Dr. Doeleman is already laying the foundation stone for the next-generation Event Horizon Telescope, which will produce films of this magnetic drive structure in action.
“This is really the next big question,” said Dr. Doeleman. “How do magnetic fields extract energy from a spinning black hole? We know it happens, but we don’t know how it works. To solve that, we have to create the first black hole cinema. “