Why Sagittarius A Spins Oddly: New Insights from the Event Horizon Telescope

The peculiar spin of Sagittarius A* could be the consequence of a merger with another supermassive black hole.

Scientists now think they may know why Sagittarius A*, also known as Sagittarius A Star, the supermassive black hole at the center of the Milky Way, is spinning in an odd manner. Researchers hypothesize that this cosmic giant most likely combined with another black hole billions of years ago based on fresh data from the Event Horizon Telescope. The black hole's fast, misaligned spin, which is different from the direction of the rest of the galaxy, would be explained by this enormous impact.

The Merger's Function in the Evolution of Black Holes

Sagittarius A* is a huge object that is 4 million times the mass of the Sun and is situated 26,000 light-years from Earth. Astronomers have long been perplexed by its quick rotation and peculiar tilt, but fresh evidence suggests a violent past.

The University of Nevada, Las Vegas (UNLV) astronomer Yihan Wang headed a team of researchers who concluded that a merger with another supermassive black hole would be the most likely explanation for the black hole's peculiar spin. Their findings were published in the journal Nature. This event might have had a significant impact on the spin of Sagittarius A* and occurred approximately 9 billion years ago.

It is thought that supermassive black holes expand through merging with other black holes formed by galaxy collisions, in addition to taking up surrounding gas and dust. Co-author of the paper and UNLV physics and astronomy professor Bing Zhang indicated that the merger most likely occurred following a collision between the Milky Way and the Gaia-Enceladus galaxy. This provides important support for the idea that black holes can grow by merging with other similar objects.

Subsequent Findings Wait for

Future space-based initiatives like the Laser Interferometer Space Antenna (LISA), scheduled for deployment in 2035, are expected to contribute to the understanding of the supermassive black hole's evolutionary history. With the use of these instruments, gravitational waves from these kinds of mergers will be detected, offering further information about the dynamic evolution of galaxies and their black holes.