This is an image of polarized light in the vicinity of the supermassive black hole in the center of the M87 galaxy. The collaboration of Event Horizon Telescope – a global network of radio antennas – noticed it. The lines indicate the orientation of the polarized light, which is directly related to the magnetic field lines of the black hole. Thus, for the first time, we have an image that shows the “signature” of the magnetic fields around a black hole. Image via EHT / ESO.
In 2019, astronomers launched the first direct image of a black hole, a feat that has made headlines and minds crazy around the world. The black hole was a supermassive one – millions of times the mass of our sun – in the heart of a relatively close galaxy known as M87. On March 24, 2021, the Event Horizon Telescope – the same global collaboration that captured the black hole of the M87 – launched a new image showing the polarized light in this black hole. The polarization of light gives astronomers a signature (a representation) of the magnetic field of a black hole for the first time.
Astronomers have published their results in two papers (here and here) in peer review Astrophysical Journal Letters on March 24, 2021, with a third accepted for publication soon (here).
The black hole in the M87 sends huge jets – matter evacuated at almost the speed of light – from its core. These observations are a key to understanding how this happens, these astronomers said. Astronomer Monika Moscibrodzka of Radboud University in the Netherlands said in a statement:
We see the following crucial evidence to understand how magnetic fields behave around black holes and how activity in this very compact region of space can lead to powerful jets that extend far beyond the galaxy.
Another astronomer involved in the project – Andrew Chael at the Princeton Center for Theoretical Science – went on to explain:
Recently published polarized images are essential for understanding how the magnetic field allows black holes to “eat” matter and launch powerful jets.
When you measure light emanating from an astronomical source, sometimes part of it is polarized, in the same way that light passes through a pair of polarized sunglasses. Instead of lenses, however, magnetic fields in the hot regions of space polarize astronomical light. Thus, using telescopes to measure how light is polarized will give you direct information about the magnetic fields that caused it.
Another member of the team at this black hole study – Jason Dexter of the University of Colorado, Boulder – explained:
Observations suggest that the magnetic fields at the edge of the black hole are strong enough to push back the hot gas and help it withstand gravity. Only gas that slides through the field can spiral inward to the horizon of events.
M87 is a huge elliptical galaxy located 55 million light years from us. Its central supermassive black hole is one of the most massive known and, like a cosmic reflector, a jet of subatomic particles traveling at almost the speed of light flows from it, up to about 6,000 light-years. Image via NASA / ESA / Hubble Heritage team.
M87 is a huge elliptical galaxy – made up mainly of older stars and does not have the well-known spiral pattern of disk galaxies – which is relatively close, 55 million light-years away, in the group of Virgo galaxies. It is about twice the mass of our own Milky Way galaxy and contains about 10 times as many stars. Another strange thing about this galaxy is that it has an unusual number of globular clusters of stars, about 12,000 of them, which can be compared to the humbler number of 200 in the Milky Way.
The supermassive black hole of M87 is, in direct relation to the size of its host galaxy, one of the most massive we know.
A diagram of the M87 and its jet emanating from the central black hole. Top: An image in visible (optical) light shows the jet stretching thousands of light-years from the center. The following 3 images show the inner parts of the jet and the central region of the black hole in polarized light, thus indicating how the magnetic fields behave in these regions. Each image is getting closer and closer to the supermassive black hole. The horizontal line is an indicator of the scale of each image, given in light years. Read more about this image at ESO.
Bottom line: Astronomers have launched a new image of the supermassive black hole in the center of the nearby M87 galaxy, this time showing the signatures of magnetic fields.
Source: The first results of the Orizont M87 telescope. ARE YOU COMING. Ring polarization
Source: The first results of the Orizont M87 telescope. VIII. The structure of the magnetic field near the event horizon
Source: Polarimetric properties of ALMA event horizon telescope targets
Through ESO
