Once a week.
Subscribe to our weekly newsletter.
Study: spinning black holes power jets with magnetic reconnection
A new study discovers how blazars shoot out jets of radiation towards Earth.
- New research discovers what mechanism powers radiation jets from blazars.
- Scientists found that magnetic reconnection is responsible for boosting the cores of the jets.
- The study's conclusion is like deciphering a "hieroglyph in the black hole alphabet," says author.
A new study sheds light on the hidden mechanisms propelling plasma jets that shoot out from spinning black holes.
One of the most dramatic space events occurs when a black hole powers up a blazar, a region of space producing a huge jet of radiation streaming towards Earth. These can reach hundreds of thousands of light years into space.
What's unusual, scientists noticed, is that while we can see the jet, the black hole emitting it stays hidden. All we can gauge about its existence is a shadow courtesy of bent light rays near the black hole. The jet's core, however, appears to be located at the distance of over a thousand times the shadow, prompting the question – how did it get there? How does the energy from the black hole reach the jet's core? And where does the energy for the blast of particles come from in the first place?
Using NASA's space telescope Fermi-LAT to observe quasar 3C279 (also housing a black hole), astrophysicist Amit Shukla found that the jet's core, located in the millimeter wavelength range, emits high-energy gamma radiation that constantly flickers, its brightness able to double within a few minutes. This pattern of changes corresponds to the process of magnetic reconnection, spotted in astrophysical objects that have strong magnetic fields, as reports the press release on the study. This process can also be influenced by solar activity.
While reconnection is taking place, invisibly stored energy is released from the magnetic field in the form of "mini-jets". Accelerated particles within these jets are responsible for the observed gamma radiation.
Shukla, currently of the Indian Institute of Technology in Indore, India, conducted a part of the research while working at the Julius-Maximilians-Universität (JMU) Würzburg in Bavaria, Germany.
"I saw how the analysis of the data revealed the special pattern of magnetic reconnectionin the light curve," explained Shukla. "It felt as if I had suddenly deciphered a hieroglyph in the black hole alphabet."
Professor Karl Mannheim, head of the JMU Chair of Astronomy and co-author of the paper, shared that spacetime near the black hole they examined is "forced to swirl around" in so-called "corotation." He further elucidated the events, highlighting that "Magnetic fields anchored to the plasma around the black hole expel the jet slowing down the black hole's rotation and converting part of its rotational energy into radiation."
Check out their study published in Nature Communications.
- 4 Things That Currently Break the Speed of Light Barrier - Big Think ›
- New data reveals Earth closer to a black hole and 16,000 mph faster - Big Think ›
- Columbia study finds new way to extract energy from black hole - Big Think ›
Some mysteries take generations to unfold.
- In 1959, a group of nine Russian hikers was killed in an overnight incident in the Ural Mountains.
- Conspiracies about their deaths have flourished ever since, including alien invasion, an irate Yeti, and angry tribesmen.
- Researchers have finally confirmed that their deaths were due to a slab avalanche caused by intense winds.
a: Last picture of the Dyatlov group taken before sunset, while making a cut in the slope to install the tent. b: Broken tent covered with snow as it was found during the search 26 days after the event.
Photographs courtesy of the Dyatlov Memorial Foundation.<p>Finally, a <a href="https://www.nature.com/articles/s43247-020-00081-8" target="_blank">new study</a>, published in the Nature journal Communications Earth & Environment, has put the case to rest: it was a slab avalanche.</p><p>This theory isn't exactly new either. Researchers have long been skeptical about the avalanche notion, however, due to the grade of the hill. Slab avalanches don't need a steep slope to get started. Crown or flank fractures can quickly release as little as a few centimeters of earth (or snow) sliding down a hill (or mountain). </p><p>As researchers Johan Gaume (Switzerland's WSL Institute for Snow and Avalanche Research SLF) and Alexander Puzrin (Switzerland's Institute for Geotechnical Engineering) write, it was "a combination of irregular topography, a cut made in the slope to install the tent and the subsequent deposition of snow induced by strong katabatic winds contributed after a suitable time to the slab release, which caused severe non-fatal injuries, in agreement with the autopsy results."</p><p>Conspiracy theories abound when evidence is lacking. Twenty-six days after the incident, a team showed up to investigate. They didn't find any obvious sounds of an avalanche; the slope angle was below 30 degrees, ruling out (to them) the possibility of a landslide. Plus, the head injuries suffered were not typical of avalanche victims. Inject doubt and crazy theories will flourish.</p>
Configuration of the Dyatlov tent installed on a flat surface after making a cut in the slope below a small shoulder. Snow deposition above the tent is due to wind transport of snow (with deposition flux Q).
Photo courtesy of Communications Earth & Environment.<p>Add to this Russian leadership's longstanding battle with (or against) the truth. In 2015 the Investigative Committee of the Russian Federation decided to reopen this case. Four years later the agency concluded it was indeed a snow avalanche—an assertion immediately challenged within the Russian Federation. The oppositional agency eventually agreed as well. The problem was neither really provided conclusive scientific evidence.</p><p>Gaume and Puzrin went to work. They provided four critical factors that confirmed the avalanche: </p><ul><li>The location of the tent under a shoulder in a locally steeper slope to protect them from the wind </li><li>A buried weak snow layer parallel to the locally steeper terrain, which resulted in an upward-thinning snow slab</li><li>The cut in the snow slab made by the group to install the tent </li><li>Strong katabatic winds that led to progressive snow accumulation due to the local topography (shoulder above the tent) causing a delayed failure</li></ul><p>Case closed? It appears so, though don't expect conspiracy theories to abate. Good research takes time—sometimes generations. We're constantly learning about our environment and then applying those lessons to the past. While we can't expect every skeptic to accept the findings, from the looks of this study, a 62-year-old case is now closed.</p><p> --</p><p><em>Stay in touch with Derek on <a href="http://www.twitter.com/derekberes" target="_blank">Twitter</a> and <a href="https://www.facebook.com/DerekBeresdotcom" target="_blank" rel="noopener noreferrer">Facebook</a>. His most recent book is</em> "<em><a href="https://www.amazon.com/gp/product/B08KRVMP2M?pf_rd_r=MDJW43337675SZ0X00FH&pf_rd_p=edaba0ee-c2fe-4124-9f5d-b31d6b1bfbee" target="_blank" rel="noopener noreferrer">Hero's Dose: The Case For Psychedelics in Ritual and Therapy</a>."</em></p>
As patients approached death, many had dreams and visions of deceased loved ones.
One of the most devastating elements of the coronavirus pandemic has been the inability to personally care for loved ones who have fallen ill.
Research reveals a new evolutionary feature that separates humans from other primates.
- Researchers find a new feature of human evolution.
- Humans have evolved to use less water per day than other primates.
- The nose is one of the factors that allows humans to be water efficient.
A model of water turnover for humans and chimpanzees who have similar fat free mass and body water pools.
Credit: Current Biology
Being skeptical isn't just about being contrarian. It's about asking the right questions of ourselves and others to gain understanding.