On Wednesday, astronomers made a significant announcement, revealing the discovery of a robust and intricately arranged magnetic field, spiraling around the supermassive black hole situated at the heart of the Milky Way. This finding unveils previously undisclosed attributes of the immensely potent entity residing within our galaxy.
The configuration of this magnetic field, extending from the periphery of the black hole known as Sagittarius A* (Sgr A*), bears a striking resemblance to the magnetic field enveloping the sole other black hole ever captured in an image, which exists in a larger form at the core of a neighboring galaxy called Messier 87 (M87). According to the researchers, this similarity suggests that robust magnetic fields might be a prevalent characteristic among black holes.
Researchers noted that the magnetic field surrounding the black hole in M87, known as M87*, facilitates the emission of potent jets of material into space. This suggests that although similar jets haven’t been observed yet around Sgr A*, they could potentially exist and might become observable in the near future, they suggested.
The researchers unveiled a fresh image depicting the surroundings of Sgr A* in polarized light, marking the first time the magnetic field structure has been revealed. This polarized light originates from subatomic particles known as electrons orbiting along magnetic field lines. Sgr A* boasts a mass 4 million times that of our sun and resides approximately 26,000 light-years away from Earth, equivalent to a distance of 5.9 trillion miles (9.5 trillion km).
“Astronomer Sara Issaoun, from the Center for Astrophysics – Harvard & Smithsonian and one of the research co-leaders, remarked, ‘For some time, we’ve held the belief that magnetic fields play a pivotal role in the feeding and expulsion of matter from black holes in formidable jets.’ Issaoun continued, ‘This latest image, coupled with the remarkably analogous polarization structure observed in the significantly larger and more potent M87* black hole, underscores the vital importance of robust and organized magnetic fields in the interactions of black holes with the surrounding gas and matter.'”
“Black holes, being incredibly dense entities with gravity so intense that even light cannot escape, present formidable challenges for observation,” explained astronomer Angelo Ricarte from the Center for Astrophysics. “The observed organization of the magnetic field into a spiral, akin to M87*, suggests that the black hole has the capacity to generate highly efficient jets that extend into the galaxy.”
The latest image, akin to previous portrayals of Sgr A* and the M87 black hole, was captured utilizing the Event Horizon Telescope (EHT), an international scientific collaboration that leverages a global network of observatories to collectively observe radio sources associated with black holes.
The event horizon of a black hole marks the boundary beyond which anything—be it stars, planets, gas, dust, or any form of electromagnetic radiation—is inevitably drawn into oblivion.
“By capturing polarized light emitted by the intensely hot gas near black holes, we can directly discern the structure and potency of the magnetic fields that permeate the flow of gas and matter consumed and expelled by the black hole,” stated Issaoun. “Compared to prior findings, the analysis of polarized light offers deeper insights into astrophysical phenomena, the characteristics of the gas, and the mechanisms involved as a black hole consumes matter,” she emphasized.
Light, an oscillating electromagnetic wave enabling the visibility of objects, can sometimes oscillate in a particular orientation, a phenomenon known as polarized light.
The M87 black hole, situated at the center of a vast elliptical galaxy, possesses a mass six billion times that of our sun. It emits a formidable jet of plasma—a state of matter so hot that some or all of its atoms are ionized into subatomic particles like electrons and ions—that is observable across all wavelengths. Researchers note mounting evidence suggesting the existence of a jet emanating from Sgr A*.
“We’re particularly intrigued by the prospect of a potent jet. With advancements in our instrumentation anticipated in the coming years, if such a jet exists, we should be able to discern it from the data,” remarked Ricarte.
These findings have been detailed in the Astrophysical Journal Letters.
