As the Event Horizon Telescope collects data for its remarkable new image of the Milky Way’s largest black hole, an army of other telescopes, including NASA’s three space X-ray observatories, are also watching. the Milky Way galaxy – the Sagittarius A * (Sgr A * for short) – co-operates with, and nourishes, nearly 27,000 light-years across Earth.
While the Event Horizon Telescope (EHT) saw Sgr A * in April 2017 create a new image, scientists collaborated once again peeking into a single black hole with areas that received different lengths of light. In this multiwavelength viewing campaign, they combined X-ray data from NASA’s Chandra X-ray Observatory, Nuclear Spectroscopic Telescope Array (NuSTAR), and Neil Gehrels Swift Observatory; radio data from the East Asian Very Long-Baseline Interferometer (VLBI) network and the Global 3-millimeter VLBI array; and infrared data from the European Southern Observatory’s Very Large Telescope in Chile.
Event Horizon Telescope
“The Event Horizon Telescope has taken another amazing photo, this time of a huge black hole in the center of our home galaxy,” said NASA Director Bill Nelson. “A closer look at this black hole will help us learn more about its universal effects in its area, and be an example of international cooperation that will take us to the future and unleash things we never thought possible.”
One important goal was to capture X-ray flares, which are thought to be driven by magnetic fields similar to those seen in the Sun, but can have tens of millions of times more energy. This burning occurs almost daily in the space observed by EHT, a region slightly larger than the Sgr A * event horizon, the point of no return of the story that falls within. Another goal was to obtain critical clues as to what was happening on the larger scales. Although the EHT effect shows a striking resemblance between the Sgr A * and its predecessor black hole, the M87 *, the overall picture is much more complex.
EHT image
“If a new EHT image shows us the eye of a dark storm, then this multiwavelength observation reveals wind and rain equivalent to hundreds or thousands of miles to pass,” said Daryl Haggard of McGill University in Montreal, Canada, who is one. of leading scientists of the multiwavelength campaign. “How does this cosmic storm combine and disrupt even the surrounding galaxy?”
One of the great questions that goes on around black holes is how they collect, import, or even emit substances around them near light speeds, through a process known as “accretion.” This process is fundamental to the formation and growth of planets, stars, and black holes of all sizes, in the universe.
Gravitational pull of the black hole
Chandra images of the hot gas around Sgr A * are important in the study of growth because they tell us how important the photographs of the nearby stars are the gravitational pull of the black hole, and how close they are to the horizon. This important information is not available with the current telescopes of any other black hole in the universe, including the M87 *.
“Astronomers can strongly agree on the basics – that black holes have surrounding objects and some fall on the scene forever,” said Sera Markoff of the University of Amsterdam in the Netherlands, another coordinator for multiwavelength observation. “With all the information we have collected Sgr A * we can go even further than this basic image.”Scientists in large international collaborations are comparing data from NASA’s high-powered machines with other telescopes and modern computer models considering factors such as Einstein’s common theory of relativity, the effects of magnetic fields, and predicting how much radiation around a black hole should produce different waves.
Comparisons of models and measurements give evidence that the magnetic field around the black hole is strong and that the angle between the optical line of the black hole and its spin-axis is low – about 30 degrees. If confirmed this would mean that in our area we are looking down on Sgr A * and its ring more than we are if we look forward, in an astonishing way similar to the original EHT target M87 *.”None of our models are completely data-intensive, but now we have specific information on which to work,” said Kazuhiro Hada of Japan’s National Astronomical Observatory. “If we have more data it will make our models more accurate, and ultimately our understanding of the accumulation of black holes, it will be.”
The researchers were also able to capture X-ray flares – or explosions – from Sgr A * during EHT surveillance: blurred vision with Chandra and Swift, as well as limited light detection by Chandra and NuSTAR. X-ray flares with the latest light are frequently seen with Chandra, but this is the first time EHT has seen Sgr A * at the same time, providing an amazing opportunity to identify a responsible approach using realistic images.
The intensity of the millimeter wave and the EHT-marked variability increase in a few hours immediately after X-ray brightness, something that had not been seen in millimeter detection a few days earlier. Analysis and interpretation of EHT data immediately after the outbreak will be reported in future publications.
The results of the EHT group are published May 12 in a special issue of the Astrophysical Journal Letters. The effects of multiwavelength are described in detail in paper II and V.NASA’s Marshall Space Flight Center is in charge of the Chandra program. The Smithsonian Astrophysical Observatory’s Chandra X-ray Center manages scientific operations from Cambridge, Massachusetts, and the operation of a plane from Burlington,
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