After the first photo of a black hole, the first image of its magnetic field arrives: the protagonist is once again the black hole of the galaxy M87, 55 million light years away.
It was obtained by the same collaboration Event Horizon Telescope (Eht), to which the historical photo of 2019 is due.
Images of the magnetic field of the black hole of the galaxy M87 taken with different telescopes (source: EHT Collaboration; ALMA (ESO / NAOJ / NRAO), Goddi et al .; VLBA (NRAO), Kravchenko et al .; JC Algaba, I. Martí -Vidal)
The study, published in Astrophysical Journal Letters, was conducted with the collaboration of the European Southern Observatory (Eso) and with an important Italian participation, with the National Institute of Nuclear Physics (Infn) and the National Institute of Astrophysics (Inaf ).
The image of the magnetic field, on the edge of the black hole, helps to understand how the jets of particles manage to extend beyond the galaxy.
The black hole of the galaxy M87 photographed by the Alma telescope (source: ALMA (ESO / NAOJ / NRAO), Goddi et al.)
Also on this occasion, as happened for the photo of 2019, the researchers of the Eht collaboration worked by connecting eight telescopes around the world, in order to obtain a virtual telescope the size of the Earth, the Event Horizon Telescope.
The 66 antennas of the Alma radio telescope (Atacama large millimeter / submillimeter array) of the Southern European Observatory (Eso) were also used.
In this way, the Eht virtual telescope made it possible to obtain a resolution equivalent to that necessary to measure, from the Earth, an object as large as a credit card on the surface of the Moon.
The galaxy M87 photographed by the Very Large Telescope (source: ESO)
On 10 April 2019, the same researchers of Eht had made public the first photo of a black hole, which showed a bright ring structure with a dark central region: the shadow of the black hole.
Now, with this new photo, I am able to better understand the physics behind the 2019 image.
In the same way that polarized sunglasses help to see better by reducing glare and surface glare. bright, the researchers sharpened the view of the region around the black hole by observing how polarized the light that escapes from it is.
The streaks shown in the image thus made it possible to obtain the map of the magnetic field ends present on the edge of the black hole.
"We can say that we have added another page to the physics of black holes. No one had been able to get this close to the event horizon so far," explains Mariafelicia De Laurentis, of the Federico II University of Naples and Infn. and member of the Scientific Council of Eht.
"Understanding these magnetic fields - he concludes - is essential to understand which parts of the magnetic field are responsible for the high-energy jets emitted by black holes".
