It has been close to two years since the world was first introduced to Sagittarius A* (Sgr A*), the supermassive black hole residing at the center of the Milky Way.
A true behemoth, Sgr A* boasts a mass equivalent to 4 million suns and is encircled by hot pockets of swirling gas. Despite its immense size, it sits about 27,000 light-years away from Earth, appearing in the sky only as large as a donut on the moon’s surface.
In a recent study published in the Astrophysics Journal Letter and released by the event horizon telescope (EHT), Sgr A* was captured in polarized light for the first time.
Similar to how sunglasses can filter polarized light from the sun, astronomers utilize polarized light to unveil concealed magnetic fields.
The lines within the image indicate the direction of polarization, which correlates with the structure of the magnetic field surrounding the black hole.
“The spiral pattern observed swirling around the black hole signifies that the magnetic field must also be swirling, indicating a very strong and ordered field,” stated Dr. Sarah Isaun, an Einstein Fellow and co-leader of the project in the NASA Hubble Fellowship Program, as quoted in BBC Science Focus.
The first-ever image of a black hole was unveiled by EHT in 2019, featuring a much grander black hole at the core of the Messier 87 galaxy (M87*).
M87* is approximately 1,000 times heavier than Sgr A*, leading to a slower rotation making it easier to image.
Further developments include astronomers releasing images of the magnetic field encompassing M87* in 2021. Overcoming the challenge of capturing our own supermassive black hole in polarized light took an additional three years.
In a surprising revelation, despite the contrasting sizes of the two black holes, the new images demonstrate strikingly similar magnetic field structures, emphasizing the prevalence of strong magnetic fields in both. This highlights a fundamental feature of supermassive black holes.
Isaun emphasized, “Sgr A* now holds a polarization structure remarkably akin to the larger, more potent M87* black hole, supporting the significance of a robust, well-ordered magnetic field in these entities.”
Previous investigations on M87* disclosed that the encircling magnetic field generates potent jets of energy and matter extending far beyond the galaxy. While astronomers have visualized the jet around M87*, it has remained elusive around Sgr A*. However, recent images unveil remarkable similarities between the two black holes, suggesting the potential existence of jets in both.
Isaun highlighted, “The jets within the host galaxy can stimulate or counteract star formation, exhibiting a fascinating interplay between the dynamics of these emanating jets from these black holes and the evolvement of the host galaxy. There exists a connection.”
“I believe we can extract valuable insights into our galaxy’s history from this connection.”
The upgraded EHT is set to observe Sgr A* once more next month, with astronomers hopeful of uncovering concealed jets and other facets of the galaxy’s central region.
Anticipate further groundbreaking revelations from EHT, potentially including more awe-inspiring images and even real-time video footage in years to come.
About our experts
Sarah Isaun is an observational astronomer and member of the Event Horizon Telescope (EHT) collaboration. Her research focuses on aggregating, calibrating, and visualizing millimeter-wave radio observations of supermassive black holes. She led a project to produce new images of Sagittarius A* in polarized light.
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Source: www.sciencefocus.com
