A team of scientists has found the magnetic fields that power the Milky Way’s supermassive black hole, right outside its event horizon. The team theorizes that this magnetic field is what makes the black hole so powerful.
Understanding Magnetic Fields Will Help Us Understand the Universe
This is the first instance where magnetic fields are directly visible from the event horizon. The Milky Way is one of many galaxies sporting a supermassive black hole at its core, but having spotted these magnetic fields brings some changes to the game. The team of scientists used the Event Horizon Telescope to observe the magnetic fields around Sagittarius A. By putting the network of EHTs to work, scientists were able to see even compact black holes.
A Different Kind of Astronomical Exploration
This new adventure sets the astronomical community on a different kind of journey, and they hope to capture the black hole’s event horizon within the next couple of years. What they’re looking for now is for polarized light, but not just any kind. There’s a specific kind of signature that a magnetic field leaves behind, and it can be traced through that sort of polarized light. This could help retrace the magnetic field itself and discover patterns of neighboring ones.
Further research is naturally necessary in order to discover what exactly is it that causes the high-energy jets that black holes shoot. On the view that the team has acquired so far, they commented that the magnetic fields are dancing all around the place. The astronomical community is once again thrown in a journey that it was not prepared for but is only too happy to take on as they go on to discover more things about the structure of our galaxy, from how it came to be and how it is now.
An ancient practice of ritualistic cleansing in South African agricultural communities has led researchers to record a magnetic field history of the region that is believed to play a major role in the reversal of Earth’s magnetic poles. The study, which was the first of its kind, was published in the journal Nature Communications.
Study is First to Record Magnetic Field History in South Africa
Three universities teamed up to acquire the first record of magnetic fields in South Africa using minerals from the Iron Age and archaeological data from ritualistic burning ceremonies in agricultural settlements.
Research findings revealed that with the archaeological evidence and the current weakening of the magnetic fields, South Africa’s core region may be the genesis of the most recent (as in 800,000 years ago recent) and even future pole reversals, which take nearly 15,000 years to complete once started.
Their data is groundbreaking in the field of earth sciences and geophysics because it suggests that pole reversals don’t begin in random locations as previously thought.
How Archaeology and Minerals Revealed the Importance of the Magnetic Fields
Tarduno and his research team wanted to collect concrete evidence to accurately record South Africa’s magnetic fields from the Iron Age rather than use estimates from models using approximate data collected around the world. They turned to archaeologists for extra help.
These experts on ancient African rituals and practices explained the early practices of cleansing villages through burning huts and grain bins. While it seems like a rather unimportant event for geophysicists, this practice of igniting the village would have created a fire that reached over 1000 degrees Celsius as it consumed the clay floors of the structures.
This fire would be so scorching hot it would burn through, erasing the old information stored in the magnetite while creating a new record of magnetic information, like field strength and direction.
So, in other words, they would be able to actually see when the magnetic intensity in the area had increased or decreased thanks to the practices of these ancient Africans.
That’s exactly what happened too! Tarduno’s team found a 30% decrease in magnetic field intensity in the Iron Age (1225 to 1550 AD). This parallels what is happening today in the region, leading the researchers to the conclusion that this gradual weakening may reappear every few (thousand) years.
Earth Sciences, Geophysics, and Even More Technical Understanding of the Magnetic Fields
The research data was collected from sites along Zimbabwe and Botswana, focusing near the Limpopo River. The sites were all within a region with an extremely weak magnetic field strength called the South Atlantic Anomaly (SAA).
Other research has shown Earth’s magnetic field in the North and South Poles has decreased 16% of the past nearly 200 years with most of the weakening has occurred in the SAA. Some scientists believe this is the first sign of the Earth going into a pole reversal. However, the research team has said that weakening fields may recover without the poles reversing. It happens all the time!
Meanwhile, their study has proven, for the first time, that the low magnetic field strength in the Southern Hemisphere’s SAA is a result of geology. This region features a core that is overlain with hot, dense mantle rock that is 3000 km below the surface and 6,000 km across the region.
So How Does South Africa Fit Into This?
The researchers hypothesized that the specific region in South Africa actually affects Earth’s magnetic field as the liquid iron within the Earth shifts its flow near the region thanks to the special feature of the hot, dense mantle rock. This shift causes irregularities in the field, which results in lesser magnetic intensities.
The area, which is called a Large Low Shear Velocity Province (LLSVP), is theorized to perhaps be the trigger for magnetic pole reversals as the weak magnetic field gets larger.
However, the research team pointed out that though the new data is interesting, it cannot predict or conclusively say that we are in a reversal or will soon be in one. Instead, it simply suggests that the latest research on magnetic fields in South Africa shows a possible pattern in Earth’s pole reversals, which in itself is pretty impressive.
Two years ago, scientists identified a gigantic magnetar near the Milky Way’s supermassive black hole. Magnetars are collapsed neutron stars with extremely powerful magnetic fields. This particular magnetar happens also to be the closest interstellar entity to the 4-million-solar mass black hole in the middle of the Milky Way galaxy, at a distance of approximately 0.3 light-years (at least 2 trillion miles). In recent discoveries, the magnetar — nicknamed SGR 1745-2900, for research purposes — appears to have not only a higher observed amount of x-rays than previously observed magnetars, but also maintains much higher surface temperatures.
Into the heart of the Milky Way’s darkness — light at the nucleus
It all started when astronomers wanted to observe the circuit of the magnetar around the black hole (called the “sagittarius A-star”) at the center of the Milky Way. Scientists have long concluded that our entire galaxy revolved around this black hole, and until recently did not detect the one galactic body that lives appallingly close to the black hole. Scientists are predicting that it sits at least 2 trillion miles away from the center of the hole. This seems like an indomitable distance, but when the magnitude of the black hole’s 4-million-sun mass is factored in, the position of the magnetar seems exceedingly precarious.
This magnetar, observed using NASA’s Chandra X-ray Observatory and the ESA’s XMM-Newton, is showing peculiar signs. The studies derived from the space telescopes have indicated specifically that the magnetar’s surface is much hotter than expected of its star type, and that its x-ray emissions appear to be lowering at a rate slower than that of other observed magnetars. Scientists first turned to the phenomenon of “starquakes” to expand on the theory for an explanation. When neutron stars form, a crust develops on its condensed surface. In some cases, this crust will crack and fracture, just like earth’s surface does during an earthquake.
Ultimately, however, the researchers dispelled this possible explanation, since they garnered information showing that the speed at which surface temperatures are cooling, and at which the light of x-rays on the star is fading, didn’t exactly match the projections given by the star-quake mechanism.
Particles in magnetic fields may account for magnetar’s high heat
Perhaps a likelier explanation for the magnetar’s dauntingly high temperatures and high supply of x-rays lies in the charged particles trapped in magnetic fields above the star’s surface. Twisted in bundles, these particles (which are created when neutron stars form) may constantly batter the surface below, administering an increased layer of heat on it.
Ever since the concept of “matter” was introduced to our understanding, scientists and enthusiasts alike have been hindered by the mystery surrounding anti-matter. Based on existing theories, the Big Bang would have presumably produced both matter and anti-matter in entirely equal amounts. In this scenario, they would have instantly canceled each other out. In the end, matter “won” in the universe, creating all that exists to the human eye today. Recently, however, NASA’s Fermi Gamma-ray Space Telescope has picked up bizarre high-energy light that could explain how matter ultimately overpowered anti-matter.
The telescope discovery shows signs of a critical magnetic field
To delve into these tensions between matter and anti-matter, we have to examine the evidence. Many scientists claim unequivocally that the universe contained equal amounts of both matter and anti-matter (with equal yet opposing charges) since its conception. Currently, the presence of anti-matter is diminished, and the true mystery that lingers searches for a precise explanation as to why matter dominated — and why it even exists — in the universe.
The specific gamma light rays that the Fermi telescope distinguished took on a spiral-shaped imprint, informing researchers that they most probably sprung from a magnetic field that had formed nanoseconds after the Big Bang. They speculate that within this magnetic field lies the evidence that the amount of matter truly surpasses that of anti-matter.
Tanmay Vachaspati, a physics professor at Arizona State University and the leader of this research, has found that properties identified in the gamma ray data indicate an extremely large production of matter over anti-matter in our early universe. Further analysis of the ray’s imprints showed that the magnetic field is primarily left-handed. This is especially significant, since anti-matter would have largely produced fields of a right-hand orientation.
If correct, magnetic field theory could lead to more finds on anti-matter
Despite the great feasibility of this explanation, there remains the slightest margin of error. The next step would be to gather even more data given by the Fermi telescope, and extract additional signs that indicate the solid presence matter, and to prove the correlation between matter and the magnetic field, as well as the near-absolute nonexistence of anti-matter in the field.
