Two years ago he had already become a ‘star’ with his shots on all media but Now
the black hole at the center of the galaxy M87 was photographed as we have never seen it before, providing a myriad of information to scientists. The scientific collaboration Eht-Event Horizon Telescope, which in 2019 had published the first ‘photo’ of a black hole, has now managed to create a new representation of the enormous astrophysical object at the center of the galaxy M87: it is the image of the black hole as it appears in polarized light.
It is the first measure of the polarization of light – phenomenon indicating the presence of magnetic fields – in a region practically on the ‘edge’ of a black hole, on the so-called event horizon. “The result provides a fundamental contribution” to explain how the galaxy M87, which is 55 million light years away from us, emits energetic jets of particles from its core. It all starts on April 10, 2019 when EHT scientists showed the world the first ever image of a black hole, a ‘photo’ that showed a bright ring structure with a dark central region: the shadow of the black hole. precisely. Since then, the team has delved further into the analysis of data collected in 2017 on the supermassive astrophysical object at the heart of the galaxy M87, succeeding in observing that a significant fraction of the light around M87’s black hole is polarized. “This work represents a milestone in this field because, by studying the polarization of light, it is possible to obtain information that allows us to better understand the physics behind the image of 2019 ” mark Infn, Inaf and Federico I University
I of Naples announcing today the research results that involved over 300 researchers of multiple organizations and universities around the world.
From this study, in fact, valuable information is obtained, useful for understanding the behavior of magnetic fields around black holes and the processes that, in these very dense regions of space, are able to produce jets so powerful that they extend far beyond the galaxy. “Understanding these magnetic fields is critical, and no one has been able to get this close to the event horizon until now.” explains Mariafelicia De Laurentis, professor at the Federico II University of Naples and researcher at the Infn– National Institute of Nuclear Physics, member of the Scientific Council of Eht and coordinator of the Gravitational Physics Input group of the collaboration. “Our measurements-continues De Laurentis- provide direct evidence of this phenomenon confirming decades of theoretical work, which are also fundamental in determining which parts of the magnetic field are responsible for the high-energy jets emitted by black holes. We can say that we have added another page to black hole physics. “” This new polarized light image is based on the same data collected in 2017, but it took years of work to develop the complex data analysis techniques, and to validate them through simulations “adds Ciriaco Goddi, researcher at the Dutch universities of Nijmegen and Leiden and associate researcher at the National Institute of Astrophysics (INAF).
Goddi points out that “the very powerful relativistic jets launched by supermassive black holes such as the one at the center of the galaxy M87 have been studied over the years with various instruments, including the Hubble Space Telescope, but only now have we been able to obtain a complete description of the magnetic field structures that surround them. “Scientists explain that” light becomes polarized as it passes through certain filters: this is what happens, for example, when it passes through the lenses of polarized sunglasses, which therefore they reduce glare and glare and allow us to see better. A similar phenomenon occurs when light passes through very hot regions of space that are pervaded by magnetic fields “.
Similarly, the scientists were able to refine their view of the region around the black hole studying the polarization of the light coming from there. In particular, the intensity and orientation of the polarization – visible in the image in the form of streaks – made it possible to map the magnetic field lines present on the inner edge of the black hole. “It is interesting to note that only part of the plasma ring surrounding the black hole, the one seen in the lower right image, is significantly polarized, and there is evidence that the polarization varies over the course of the week. during which we made the observations “, comments Nicola Marchili, Inaf researcher and member of the Eht scientific team at the Italian node of the Alma Regional Center, hosted at the INAF headquarters in Bologna, together with Elisabetta Liuzzo and Kazi Rygl.
“The polarized light image obtained – Marchilli underlines – allows us to obtain interesting additional information on what produces the emission that the original image of 2019 was unable to provide, and also allows us to estimate the density and temperature of the plasma” . The luminous jets of energy and matter, which escape from the core of M87 and extend for at least 5,000 light years from its center, they are one of the most mysterious and energetic phenomena in the galaxy. Most of the matter near the edge of a black hole rushes into it. However, some of the particles manage to escape moments before being captured, and are thus thrown into space in the form of jets. Scientists have used several models of how matter behaves near a black hole to better study this process, but have not yet been able to understand exactly how such large jets can be launched from its central region, which is as small as the system. Solar, nor how matter falls into the black hole.
With this new image of the black hole and its shadow in polarized light, scientists have finally been able to look for the first time into the region just outside the black hole where this interaction is taking place between the matter flowing inside and the matter being ejected. . The observations thus provide new information on the structure of the magnetic fields just outside the black hole, and the Eht collaboration has thus discovered that only theoretical models with strongly magnetized gases can explain what is seen on the black hole’s event horizon. The new data, in fact, indicate that the magnetic fields at the edge of the black hole are strong enough to repel the hot gas and help it resist the force of gravity, leaving only part of it spiraling inward, up to the event horizon. of the gas, the one that manages to slip through the magnetic field.
To observe the heart of the M87 galaxy, the collaboration connected eight telescopes around the world to create an Earth-sized virtual telescope, the Event Horizon Telescope. Among them also contributed Alma, the Atacama Large Millimeter-submillimeter Array, with its 66 high-precision antennas in the desert of Chile, strategically located on the globe to connect the entire Eht network.
The impressive resolution obtained with Eht is equivalent to what would be needed to measure from Earth an object as large as a credit card on the surface of the Moon.. This setup allowed the team to directly observe the black hole’s shadow and the ring of light around it, with the new polarized light image clearly showing that the ring is magnetized. The findings are published today in two separate articles in The Astrophysical Journal Letters from the Eht collaboration. Furthermore, a third article in the same journal, led by Goddi along with the entire collaboration, details the observations made with Alma, showing how the magnetic field structures extend from the inner edge of the black hole to well beyond the galaxy’s core. M87 for thousands of light years. The research involved over 300 researchers from multiple organizations and universities around the world. Eht is making rapid progress, with technological updates to the network and the addition of new observatories. Future Eht observations will more accurately reveal the magnetic field structure around the black hole and will give further insights into the physics of hot gases in this region.