(Press-News.org) A new image from the Event Horizon Telescope (EHT) collaboration— which includes scientists from the Center for Astrophysics | Harvard & Smithsonian (CfA)— has uncovered strong and organized magnetic fields spiraling from the edge of the supermassive black hole Sagittarius A* (Sgr A*). Seen in polarized light for the first time, this new view of the monster lurking at the heart of the Milky Way Galaxy has revealed a magnetic field structure strikingly similar to that of the black hole at the center of the M87 galaxy, suggesting that strong magnetic fields may be common to all black holes. This similarity also hints toward a hidden jet in Sgr A*. The results were published today in The Astrophysical Journal Letters.
Scientists unveiled the first image of Sgr A*— which is approximately 27,000 light-years away from Earth— in 2022, revealing that while the Milky Way’s supermassive black hole is more than a thousand times smaller and less massive than M87’s, it looks remarkably similar. This made scientists wonder whether the two shared common traits outside of their looks. To find out, the team decided to study Sgr A* in polarized light. Previous studies of light around M87* revealed that the magnetic fields around the black hole giant allowed it to launch powerful jets of material back into the surrounding environment. Building on this work, the new images have revealed that the same may be true for Sgr A*.
“What we’re seeing now is that there are strong, twisted, and organized magnetic fields near the black hole at the center of the Milky Way galaxy,” said Sara Issaoun, CfA NASA Hubble Fellowship Program Einstein Fellow, Smithsonian Astrophysical Observatory (SAO) astrophysicist, and co-lead of the project. “Along with Sgr A* having a strikingly similar polarization structure to that seen in the much larger and more powerful M87* black hole, we’ve learned that strong and ordered magnetic fields are critical to how black holes interact with the gas and matter around them.”
Light is an oscillating, or moving, electromagnetic wave that allows us to see objects. Sometimes, light oscillates in a preferred orientation, and we call it “polarized.” Although polarized light surrounds us, to human eyes it is indistinguishable from “normal” light. In the plasma around these black holes, particles whirling around magnetic field lines impart a polarization pattern perpendicular to the field. This allows astronomers to see in increasingly vivid detail what’s happening in black hole regions and map their magnetic field lines.
“By imaging polarized light from hot glowing gas near black holes, we are directly inferring the structure and strength of the magnetic fields that thread the flow of gas and matter that the black hole feeds on and ejects,” said Harvard Black Hole Initiative Fellow and project co-lead Angelo Ricarte. “Polarized light teaches us a lot more about the astrophysics, the properties of the gas, and mechanisms that take place as a black hole feeds.”
But imaging black holes in polarized light isn’t as easy as putting on a pair of polarized sunglasses, and this is particularly true of Sgr A*, which is changing so fast that it doesn’t sit still for pictures. Imaging the supermassive black hole requires sophisticated tools above and beyond those previously used for capturing M87*, a much steadier target. CfA postdoctoral fellow and SAO astrophysicist Paul Tiede said, “It is exciting that we were able to make a polarized image of Sgr A* at all. The first image took months of extensive analysis to understand its dynamical nature and unveil its average structure. Making a polarized image adds on the challenge of the dynamics of the magnetic fields around the black hole. Our models often predicted highly turbulent magnetic fields, making it extremely difficult to construct a polarized image. Fortunately, our black hole is much calmer, making the first image possible.”
Scientists are excited to have images of both supermassive black holes in polarized light because these images, and the data that come with them, provide new ways to compare and contrast black holes of different sizes and masses. As technology improves, the images are likely to reveal even more secrets of black holes and their similarities or differences.
Michi Bauböck, postdoctoral researcher at the University of Illinois Urbana-Champaign, said, “M87* and Sgr A* are different in a few important ways: M87* is much bigger, and it’s pulling in matter from its surroundings at a much faster rate. So, we might have expected that the magnetic fields also look very different. But in this case, they turned out to be quite similar, which may mean that this structure is common to all black holes. A better understanding of the magnetic fields near black holes helps us answer several open questions—from how jets are formed and launched to what powers the bright flares we see in infrared and X-ray light.”
The EHT has conducted several observations since 2017 and is scheduled to observe Sgr A* again in April 2024. Each year, the images improve as the EHT incorporates new telescopes, larger bandwidth, and new observing frequencies. Planned expansions for the next decade will enable high-fidelity movies of Sgr A*, may reveal a hidden jet, and could allow astronomers to observe similar polarization features in other black holes. Meanwhile, extending the EHT into space will provide sharper images of black holes than ever before.
The CfA is leading several major initiatives to sharply enhance the EHT over the next decade. The next-generation EHT (ngEHT) project is undertaking a transformative upgrade of the EHT, aiming to bring multiple new radio dishes online, enable simultaneous multi-color observations, and increase the overall sensitivity of the array. The ngEHT expansion will enable the array to make real-time movies of supermassive black holes on event horizon scales. These movies will resolve detailed structure and dynamics near the event horizon, bringing into focus “strong-field” gravity features predicted by General Relativity as well as the interplay of accretion and relativistic jet-launching that sculpts large-scale structures in the Universe. Meanwhile, the Black Hole Explorer (BHEX) mission concept will extend the EHT into space, producing the sharpest images in the history of astronomy. BHEX will enable the detection and imaging of the “photon ring” – a sharp ring feature formed by strongly lensed emission around black holes. The properties of a black hole are imprinted on the size and shape of the photon ring, revealing masses and spins for dozens of black holes, in turn showing how these strange objects grow and interact with their host galaxies.
Additional Information
This research was presented in two papers by the EHT collaboration published today in The Astrophysical Journal Letters: "First Sagittarius A* Event Horizon Telescope Results. VII. Polarization of the Ring" (doi: 10.3847/2041-8213/ad2df0) and "First Sagittarius A* Event Horizon Telescope Results. VIII. Physical Interpretation of the Polarized Ring" (doi: 10.3847/2041-8213/ad2df1).
The individual telescopes involved in the EHT in April 2017, when the observations were conducted, were: the Atacama Large Millimeter/submillimeter Array (ALMA), the Atacama Pathfinder Experiment (APEX), the IRAM 30-meter Telescope, the James Clerk Maxwell Telescope (JCMT), the Large Millimeter Telescope Alfonso Serrano (LMT), the Submillimeter Array (SMA), the UArizona Submillimeter Telescope (SMT), the South Pole Telescope (SPT).
Since then, the EHT has added the Greenland Telescope (GLT), which is operated by ASIAA and the CfA, the NOrthern Extended Millimeter Array (NOEMA) and the UArizona 12-meter Telescope on Kitt Peak to its network.
###
About the Event Horizon Telescope (EHT)
The EHT consortium consists of 13 stakeholder institutes; the Academia Sinica Institute of Astronomy and Astrophysics, the University of Arizona, the University of Chicago, the East Asian Observatory, Goethe-Universitaet Frankfurt, Institut de Radioastronomie Millimétrique, Large Millimeter Telescope, Max Planck Institute for Radio Astronomy, MIT Haystack Observatory, National Astronomical Observatory of Japan, Perimeter Institute for Theoretical Physics, Radboud University and the Center for Astrophysics | Harvard & Smithsonian.
About the Center for Astrophysics | Harvard & Smithsonian
The Center for Astrophysics | Harvard & Smithsonian is a collaboration between Harvard and the Smithsonian designed to ask—and ultimately answer—humanity's greatest unresolved questions about the nature of the universe. The Center for Astrophysics is headquartered in Cambridge, MA, with research facilities across the U.S. and around the world.
Media Contact
Amy C. Oliver
Public Affairs Officer
Fred Lawrence Whipple Observatory
Center for Astrophysics | Harvard & Smithsonian
Email: amy.oliver@cfa.harvard.edu
END
Astronomers unveil strong magnetic fields spiraling at the edge of Milky Way’s central black hole
2024-03-27
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
Your genes may raise your heart attack risk during high-stress times
2024-03-27
People with specific genetic traits and those who have anxiety or depression have a significantly higher heart attack risk during periods of social or political stress than at other times, according to a new study being presented at the American College of Cardiology’s Annual Scientific Session. Researchers said the findings suggest opportunities to identify those at elevated risk and perhaps even prevent cardiac events.
Doctors have long noticed that heart attacks tend to spike around certain times, such as the winter holidays, but the reasons ...
ADHD stimulants may increase risk of heart damage in young adults
2024-03-27
Young adults who were prescribed stimulant medications for attention-deficit/hyperactivity disorder (ADHD) were significantly more likely to develop cardiomyopathy (weakened heart muscle) compared with those who were not prescribed stimulants, in a study presented at the American College of Cardiology’s Annual Scientific Session.
The study found that people prescribed stimulants such as Adderall and Ritalin were 17% more likely to have cardiomyopathy at one year and 57% more likely to have cardiomyopathy at eight years compared with those who were not taking these medications. Cardiomyopathy involves structural ...
Getting too little sleep linked to high blood pressure
2024-03-27
Sleeping fewer than seven hours is associated with a higher risk of developing high blood pressure over time, according to a study presented at the American College of Cardiology’s Annual Scientific Session.
While the association between sleep patterns and high blood pressure has been reported, evidence about the nature of this relationship has been inconsistent, according to researchers. The current analysis pools data from 16 studies conducted between January 2000 and May 2023, evaluating hypertension incidence in 1,044,035 people from six countries who did not have a prior history of high blood pressure over a median follow-up of five years (follow-up ranged from 2.4 to 18 years). ...
Beating by overheating: new strategy to combat cancer
2024-03-27
Many new drugs inhibit the processes that cancer cells need to divide rapidly. So as to inhibit the cancer as a whole. But cancer cells have all sorts of workarounds to get around that effect. As a result, the tumor becomes unresponsive to treatment.
That's why researcher Matheus dos Santos Dias is taking a completely different approach. He had to convince some colleagues before he could start working on this quite surprising idea. After all, you're not going to give cancer cells a boost, are you? "We're going against the prevailing view that you can only fight cancer cells by inhibiting them," he knows. "But we had strong evidence that it also works if you overstimulate ...
Secrets of the naked mole-rat: new study reveals how their unique metabolism protects them from heart attacks
2024-03-27
This unusual, subterranean mammal with extreme longevity shows genetic adaptations to low oxygen environments which could offer opportunities for advancing other areas of physiological and medical research in humans, including the development of novel therapeutic approaches.
New research from Queen Mary University of London led by Dr Dunja Aksentijevic in the Faculty of Medicine and Dentistry has revealed that that the genome of the naked mole-rat contains specific adaptations that allow them to survive in low-oxygen, and even no oxygen environments ...
New technique for predicting protein dynamics may prove big breakthrough for drug discovery
2024-03-27
PROVIDENCE, R.I. [Brown University] — Understanding the structure of proteins is critical for demystifying their functions and developing drugs that target them. To that end, a team of researchers at Brown University has developed a way of using machine learning to rapidly predict multiple protein configurations to advance understanding of protein dynamics and functions.
A study describing the approach was published in Nature Communications on Wednesday, March 27.
The authors say the technique is accurate, fast, cost-effective and has the potential to revolutionize drug discovery ...
Risk factors for faster aging in the brain revealed in new study
2024-03-27
The researchers had previously identified a ‘weak spot’ in the brain, which is a specific network of higher-order regions that not only develop later during adolescence, but also show earlier degeneration in old age. They showed that this brain network is also particularly vulnerable to schizophrenia and Alzheimer’s disease.
In this new study, published in Nature Communications, they investigated the genetic and modifiable influences on these fragile brain regions by looking at the brain scans of 40,000 UK Biobank participants aged over 45.
The researchers examined 161 risk factors for dementia, and ranked their impact on this vulnerable ...
Understanding the role of microglia in Alzheimer’s disease
2024-03-27
Leuven, Antwerp, and London, 27 March – Microglia are specialized immune cells in the brain. While they normally protect our brains, they can also contribute to neurodegenerative diseases such as Alzheimer's. The exact mechanism behind this contribution is not yet fully understood due to the complexities involved in studying them in human brain samples. Now, a research team led by Prof. Bart De Strooper (UK-DRI@UCL and VIB-KU Leuven) and Prof. Renzo Mancuso (VIB-UAntwerp) made a xenotransplantation model – mice with stem-cell-derived human microglia in their brains to observe how human microglia respond to the disease environment. Their findings, published ...
Heat, cold extremes hold untapped potential for solar and wind energy
2024-03-27
VANCOUVER, Wash. – Conditions that usually accompany the kind of intense hot and cold weather that strains power grids may also provide greater opportunities to capture solar and wind energy.
A Washington State University-led study found that widespread, extreme temperature events are often accompanied by greater solar radiation and higher wind speeds that could be captured by solar panels and wind turbines. The research, which looked at extensive heat and cold waves across the six interconnected energy grid regions of ...
Looking to the past to prevent future extinction
2024-03-27
During the Late Pleistocene, California — at least at its lower elevations — was teeming with vegetation. While much of North America was covered in Ice Age glaciers, here, mastodons lumbered across verdant meadows, stopping to feed on brush, warily eyeing the forest’s edge for saber-tooth cats on the prowl for their calves.
Humans also flourished along the coastline, which extended hundreds of feet below where it is today.
But by 11,000 years ago, mastodons were extinct. Today, scientists are still debating the reasons for their demise: did human hunting do them in? Climate change? ...