Posted on 03/25/2021 11:23:42 AM PDT by Red Badger
Polarized view of the black hole in M87. The lines mark the orientation of polarization, which is related to the magnetic field around the shadow of the black hole. Credit: EHT Collaboration =====================================================================
Wits University astrophysicists are the only two scientists on African continent that contributed to the study.
The Event Horizon Telescope (EHT) collaboration, a multinational team of over 300 scientists including two astrophysicists from the University of the Witwatersrand (Wits University), has revealed a new view of the massive object at the center of the M87 galaxy: how it looks in polarized light.
This is the first time astronomers have been able to measure polarization, a signature of magnetic fields, this close to the edge of a black hole. The observations are key to explaining how the M87 galaxy, located 55 million light-years away, is able to launch energetic jets from its core.
“We are now seeing the next crucial piece of evidence to understand how magnetic fields behave around black holes, and how activity in this very compact region of space can drive powerful jets that extend far beyond the galaxy,” says Monika Moscibrodzka, Coordinator of the EHT Polarimetry Working Group and Assistant Professor at Radboud Universiteit in the Netherlands.
“This work is a major 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 not possible before,” explains Iván Martí-Vidal, also Coordinator of the EHT Polarimetry Working Group and GenT Distinguished Researcher at the Universitat de València, Spain. He adds that “unveiling this new polarized-light image required years of work due to the complex techniques involved in obtaining and analyzing the data.”
Professor Roger Deane, SARAO/NRF Chair in Radio Astronomy at Wits and his postdoctoral researcher, Dr. Iniyan Natarajan, are the only two scientists in the EHT collaboration that are based on the African continent. On April 10, 2019, the collaboration released the first ever image of a black hole, revealing a bright ring-like structure with a dark central region — the black hole’s shadow. Today’s results reveal that a significant fraction of the light around the M87 black hole is polarized.
“When unpolarized, the oscillations of the electromagnetic fields have no preferred direction. Filters such as polarized sunglasses or magnetic fields in space, preferentially let the oscillations in one direction pass through, thereby polarizing the light. Thus, the polarized-light image illuminates the structure of the magnetic fields at the edge of the black hole,” says Natarajan, who was part of the EHT Polarimetry Working Group.
Black holes have long been known to launch powerful jets of energy and matter far out into space. Astronomers have relied on different physical models of how matter behaves near the black hole to better understand this process. The jet emerging from M87’s core extends at least 5000 light-years from its center, the process behind which is still unexplained.
The observations suggest that the magnetic fields at the black hole’s edge are strong enough to push back on the hot gas and help it resist gravity’s pull. Only the gas that slips through the field can spiral inwards to the event horizon.
To observe the heart of the M87 galaxy, the collaboration linked eight telescopes around the world to create a virtual Earth-sized telescope, the EHT. The impressive resolution obtained with the EHT is equivalent to that needed to measure the size of a cricket ball on the surface of the Moon.
This setup allowed the team to directly observe the black hole shadow and the ring of light around it, with the new polarized-light image clearly showing that the ring is magnetized. The results are published today in two separate papers in The Astrophysical Journal Letters by the EHT collaboration.
“Peering as close as we can to the edge of black holes using cutting-edge techniques is precisely the sort of challenge we relish here at Wits,” says Deane, Founding Director of the newly approved Wits Centre for Astrophysics. “We are in a golden era for radio astronomy, and our involvement in projects like the Event Horizon Telescope and the Square Kilometre Array is at the center of our plan to carry out fundamental research, and train world-class postgraduate students who will become the leading African scientists of tomorrow.”
Natarajan was involved in simulating the black hole polarization observations and was also part of the efforts to calibrate and generate the polarized image. Deane and Natarajan have also written one of the software packages that is being used to simulate black hole observations within the EHT collaboration.
“Our collaboration developed new techniques for analyzing the polarization data, which were validated on simulations before being applied to real observations,” says Natarajan.
“Such challenging projects provide the opportunity to develop techniques which later find wider applicability in the community in ways which can pleasantly surprise us.”
More on this research:
Event Horizon Telescope Images Magnetic Fields at the Edge of M87’s Supermassive Black Hole
Ping!.......................
I posed a similar question to my kids (they like that sort of thing). If you pour a huge mass of charged particles into a black hole, what would that do to the event horizon?
It’s amazing how much stuff they can make up from seeing a meter kick or a line on a photograph.
When I let go of a magnet, it falls to the ground.
Only if there IS GROUND................
True, but in the case of no ground, letting go doesn’t do anything because there is no ground to fall to. I have to throw it somewhere or keep it with me, hence the jet.
The implication made by the author in this article seems to be that under enough gravity, the E and M in light are decoupled, an understanding of which may lead us closer to developing a unified field theory.
I view it as a towel full of water that you wring out. As you twist the towel the water comes out. But if you coat both sides of the towel with a solid coating the water will come out the ends....................
A photo of Michelle Obama’s colon?
Hmm, well, there would be a remnant of every particle on the surface of the black hole, like a 2-d projection of the 3-d particle. Since the charge of the particle counts as information, and the black hole can’t destroy information, the charges must remain on the surface of the black hole, probably contributing to the field around the black hole, since it is spinning and therefore charges on the surface would create a magnetic field.
Makes sense, and I’d venture a guess that the measure of what comes out of those ends is scalar to what goes in elsewhere. Sort of like the residue theorem in complex analysis - you can compute real integrals simply by adding up evaluations performed at singularities.
Kerr-Newman toroidal spatial warp? The donut black hole with the flat singularity in which the tidal forces cancel?? Mouth of a wormhole??? Time travel portal????
I’d be content with a really, really big bang.
Powerful Magnetic Fields Surrounding Black Hole Are Strong Enough to Resist Gravity.................. If Magnetic Force is STRONGER than the Gravity Force, even from a Black Hole, then magnets are or can be made more powerful than we thought...................
If the source of stellar power is fusion, that’s at least suggestive that we can’t reproduce controlled fusion conditions inside a building on Earth. Analogously, natural magnetic fields are unlikely to be matched by artificial ones.
No, but the never-ending stream of grant money will.......................
If you want on or off the Electric Universe/Plasma Ping List, Freepmail me.
Electromagnetism is 1039 orders of magnitude stronger than gravity. That’s 1,000,000,000,000,000,000,000,000,000,000,000,000,000 times stronger than gravity.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.
