Two years on from revealing to the world the first-ever image of a black hole, an international team of researchers from the Event Horizon Telescope (EHT) collaboration has released a stunning new image showing the black hole in polarized light.
With the updated image, viewers can see the bright magnetic fields surrounding the cosmic giant — located in the Messier 87 (M87) galaxy — in new detail. The image also brings the scientific community a step closer to understand the M87 galaxy's ability to launch enormous "energetic jets from its core."
"In the same way polarised sunglasses help us see better by reducing reflections and glare from bright surfaces, astronomers can sharpen their vision of the region around the black hole by looking at how the light originating from there is polarised," EHT explained in a press statement accompanying the new image.
For the first time, EHT scientists have mapped the magnetic fields around a black hole using polarized light waves. With this breakthrough, we have taken a crucial step in solving one of astronomy’s greatest mysteries.— Event Horizon 'Scope (@ehtelescope) March 24, 2021
Credit: EHT Collaboration#MagnetizedBlackHole #EHTBlackHole pic.twitter.com/sey42kAMSx
"Specifically, polarisation allows astronomers to map the magnetic field lines present at the inner edge of the black hole," they continued.
Over 300 researchers collaborated on the EHT project. Their collective findings were published on Wednesday, March 24, in two separate papers in The Astrophysical Journal.
The researchers explained that this is "the first time astronomers have been able to measure polarisation, a signature of magnetic fields, this close to the edge of a black hole."
EHT scientists revealed the first-ever image of a black hole in April 2019. The image of the supermassive black hole, 55 million light-years away from Earth, constituted an enormous scientific breakthrough that promises to yield new information about the role these space giants played in the formation of the universe.
The M87 supermassive black hole viewed in a new light
The new image provides a different perspective on the M87 black hole, with the polarized light showing bright streaks of light for the celestial object's magnetic field.
"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," said Monika Mościbrodzka, coordinator of the EHT Polarimetry Working Group and a professor at Radboud Universiteit in the Netherlands.
The "energetic jets" that are launched from M87's core extend at least 5,000 light-years from the black hole's center, EHT says. Though most of the matter surrounding M87 falls into the event horizon, some surrounding particles are instead blasted far into space in a massive jet stream. This process has long remained a mystery to scientists.
The newly released image potentially sheds new light on this phenomena: the polarized light perspective enables the scientists to examine the region just outside the black hole in never-before-seen detail, the researchers explain.
"This work is a major milestone: the polarisation 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," said Iván Martí-Vidal, coordinator of the EHT Polarimetry Working Group and researcher at Spain's Universitat de València.
Investigating the 'energetic jets' shooting from M87
With their new findings, the researchers believe magnetized gas might be behind the enormous jets shooting away from M87.
Fields at the edge of the black hole are strong enough to "push back on the hot gas and help it resist gravity's pull," explained Jason Dexter, coordinator of the EHT Theory Working Group and a professor at the University of Colorado Boulder.
"Only the gas that slips through the field can spiral inwards to the event horizon," Dexter continued.
More research is needed, however: EHT researchers said that future observations will allow them a greater understanding of how M87's magnetic field structure changes over time.
The first-ever image of a black hole and the new polarized light image were produced thanks to eight telescopes linked together as part of the EHT collaboration, creating a virtual Earth-sized telescope. The image is also the product of years of honing "complex techniques" in data analysis, the researchers said.
Still, they are only at the beginning of a project that aims to vastly expand our understanding of the universe:
"Even now we are designing a next-generation EHT that will allow us to make the first black hole movies," said Sheperd Doeleman, founding director of the EHT. "Stay tuned for true black hole cinema."