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
When a magnet is laying on the ground and I position another magnet above it, with the polarity correctly aligned, I can lift that magnet up!
I can lift tons of iron scrap up given a strong magnet and a crane. I can make a huge train, "levitate" off of the ground given electromagnets and electric currents.
Gravity is weak.
I’d be tickled with an old fashioned tug.
Sounds like another piece of evidence for the much-derided “electric universe” hypothesis.
I have another question. Has anyone ever estimated the amount of sheer instantaneous information incorporated in any amount of single particle matter and compared it to Einsteins E=MC2 equation? What happens if they are one and the same? Could it be that information is equal to energy? Do we even have any meaningful mathematical way of quantifying information? Just asking. Way beyond my scope in any case.
Closest I can think of that’s related to the this question is the Landauer principle
https://physicsworld.com/a/landauer-principle-passes-quantum-muster
Erasure of information has associated with it a minimum amount of waste heat.
If you calculated the relativistic mass for the amount of energy dissipated, you might get your answer. But I might be just blowing a bunch of hot air.
I know its been a while since I read your response and I have been thinking about it from time to time. One of the things that sticks out in my mind is the term “Relativistic”. I was just watching a video today about micro black holes and their possible explanation if they even exist. Could this be an explanation for dark matter? The thing that I found fascinating was why if black holes lose energy “Hawking radiation” at all and eventually evaporate down, would this explain dark matter if they eventually reached a stable point? The explanation seemed to be that they simply get too small to quantumely vibrate internally anymore. Apparently they were all created after the first few micro nanoseconds which didn't actually exist after the "Big Bang". That whole relativity thing again. The guy that was giving the presentation asked the obvious question. What then happens to all that left over information? Interesting thought huh?
Regarding left over information, you might enjoy this article.
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