The Event Horizon Telescope (EHT) produced the first image of a black hole two years ago, and it has now been analyzed under polarized light, thus reaching a new milestone in astronomical observation. In this way, they were able to detect its magnetic field, which caused this dark object in the M87 galaxy to swallow matter and emit a powerful jet.
Scientific cooperation Horizon Telescope (EHT It obtained the first image of a black hole in 2019, and today it has revealed a new perspective on the massive object in the center of the planet. Milky Way M87: Appearance under polarized light.
This is the first time that astronomers have been able to measure the polarization, the “signal” of the magnetic field, so it is very close to the edge of the black hole.These observations are the key to explaining the location of galaxy M87 55 million light-years, It can launch a very powerful jet of material from its core.
He said: “We are facing unique evidence to understand the behavior of magnetic fields around black holes, and how activities in this very compact region of space drive powerful jets far beyond the Milky Way,” he said. Monika Mościbrodzka, Coordinator of the EHT Polarization Technology Working Group, Assistant Professor at Radboud University in the Netherlands.
The first black hole image released on April 10 two years ago showed a bright ring structure with a dark area in the middle-the shadow of the hole.Since then, the EHT collaboration has conducted in-depth research on the data of the supermassive object located in the center of the M87 galaxy collected in 2017 and found Most of the light around black hole M87 is polarized.
An important milestone
He explained: “This work is an important milestone: the polarization of light carries information that allows us to better understand the physics behind the image we saw in April 2019, which was impossible before. .” Iván Martí-VidalHe is also the coordinator of the EHT Rotational Optics Working Group of the University of Valencia and the researcher of the GenT project. Because of the complicated technology involved in acquiring and analyzing data, it takes many years to develop this new image under polarized light. “
When light passes through certain filters (such as polarized sunglasses lenses), or when it is emitted from a hot, magnetized area of space, the light becomes polarized. In the same way that polarized sunglasses only allow the specific direction of the electric field of the sun’s rays to pass through, astronomers can use polarizers installed in telescopes to obtain information about the direction of the optical field from space. Specifically, the polarization makes it possible to map the magnetic field lines existing on the inner edge of the black hole.
He said: “The recently released polarization image is the key to understanding how the magnetic field can cause black holes to swallow matter and emit strong jets.” Andrew Chael, EHT partner, researcher of Princeton Center for Theoretical Sciences, USA.
Luminous jets of energy and matter
The bright jets of energy and matter emanating from the core of M87 and extending at least five thousand light-years from its center are one of the most mysterious and vibrant features of the Milky Way. Most of the matter near the edge of the black hole falls into it. However, some of the surrounding particles escaped momentarily before being captured, and were expelled into space in the form of jets.
The team relied on different models of matter’s behavior near black holes to better understand this process. But they still don’t know whether it is a jet emitted from the center of the Milky Way galaxy that is larger than the Milky Way itself, its size is as small as the solar system, or how matter fell into the black hole. Using the new EHT image of a black hole, astronomers have been able to glimpse for the first time the boundary area of the black hole in which this interaction occurs between the incoming matter and the expelled matter.
Observations of theoretical interpretation
These observations provide new information about the structure of the black hole’s fringe magnetic field. The research team found that only theoretical models with strongly magnetized gases could explain what they saw in the event horizon.
“The observations show that the magnetic field at the edge of the black hole is strong enough to retain the hot gas and help it resist gravity. Only the gas that slides through the gas field can rotate to the event horizon”, Jason DexterHe is an assistant professor at the University of Colorado at Boulder and the coordinator of the EHT theoretical working group.
“The part of the surrounding matter that did not fall into the black hole is dragged by the magnetic field, producing the powerful jets we observe in the active nuclei of galaxies (such as M87), which we have not observed until now,” he said. Jose Luis GomezHe is the coordinator and leader of the EHT team of the Institute of Astrophysics of Andalusia (IAA-CSIC), which also includes researchers Rocco Lico, Zhao Guangyao, Antonio Fuentes and Antxon Alberdi. Lico added: “A variety of analytical techniques for EHT data have been used to confirm these results, which allows us to limit the physics that produces and supplies these extreme objects.”
Consortium of 8 telescopes and 300 researchers
In order to observe the heart of the M87 galaxy, this collaboration will connect eight telescopes from all over the world, including IRAM radio telescope At 30 meters from Pico Veleta (Mountains of Sierra Nevada), a virtual telescope was created, the size of which is equivalent to the Earth, or EHT. The impressive resolution obtained with EHT is equivalent to the resolution required to measure the length of a credit card on the surface of the moon.
This allows the team to directly observe the shadow of the black hole and the surrounding halo. The new polarized light image clearly shows that the black ring has been magnetized.The results were published today in two separate articles Astrophysical Journal Letter Co-signed by EHT. The research involved more than 300 researchers from multiple organizations and universities around the world.
“EHT is developing rapidly. Various telescopes including EHT have undergone technical updates, including the addition of new observatories. We hope that future EHT observations will more accurately reveal the magnetic field structure around the black hole and tell us more about it. The physical principles of the heat in the area,” he concluded Zhonghu ParkHe is a member of the EHT collaboration and a researcher at the Academia Sinica (Researcher at the Taipei Institute of Astronomy and Astrophysics, Taiwan)
The location of the participating telescopes for the Event Horizon Telescope (EHT) and the Global mm-VLBI Array (GMVA). / ESO /O.Futak
Results of the first batch of M87 Event Horizon telescopes. VII: Polarization of the ring / VIII: Magnetic field structure near the event horizon / Goddi, Martí-Vidal, Messias and EHT cooperation: the polarization characteristics of ALMA’s event horizon telescope target. ApJL, 2021.