Physicists use outflow method to measure the rotational speed of Sagittarius A* and observe the Lense-Thirring effect
A new study has revealed that the supermassive black hole at the center of our galaxy, Sagittarius A*, is spinning rapidly and causing changes in space-time. Physicists used NASA’s Chandra X-ray Observatory to observe the black hole and calculated its rotational speed using the outflow method. The study’s findings shed light on the Lense-Thirring effect, where a spinning black hole drags space-time along with its rotation. This phenomenon has important implications for understanding the role of black holes in galaxy formation and evolution.
Spinning Black Holes and the Lense-Thirring Effect
The outflow method, developed by physics professor Ruth Daly, was used to determine the spin of Sagittarius A*. This method analyzes radio waves and X-ray emissions from the accretion disk surrounding black holes. The researchers confirmed that Sagittarius A* is spinning, which results in the Lense-Thirring effect. This effect occurs when the rotation of a black hole causes space-time to be dragged along with it. Daly explains that this alters the shape of space-time, creating a non-linear and football-like appearance.
Understanding the Role of Black Holes
The alteration of space-time by spinning black holes has significant implications for astronomers. Daly emphasizes that this phenomenon provides valuable insights into the role black holes play in galaxy formation and evolution. By studying the dynamics and impact of spinning black holes, astronomers can gain a better understanding of how galaxies are shaped and evolve over time.
Measuring Spin Angular Momentum
The spin of a black hole is measured on a scale from 0 to 1, with 0 indicating no spin and 1 representing maximum spin. Previous research had not determined a consensus value for the spin of Sagittarius A*. However, using the outflow method, the researchers found that Sagittarius A* has a spin angular momentum value between 0.84 and 0.96. In comparison, M87*, a black hole in the Virgo galaxy cluster, was found to have a spin value of 1 (with a larger uncertainty of plus or minus 0.2), which is close to the maximum for its mass.
The Difference in Spin Rates
Although Sagittarius A* and M87* were found to have similar spin rates, Daly explains that Sagittarius A* spins more rapidly due to its smaller mass and shorter distance to cover. This difference in spin rates provides insights into the formation and evolution of black holes. The study suggests that Sagittarius A* likely gained a significant portion of its mass through the accretion of surrounding gas.
Implications for Galactic History
Understanding the mass and spin of black holes is crucial for unraveling their formation and evolution. Black holes formed through mergers of smaller black holes typically have a low spin value. On the other hand, black holes formed through gas accretion exhibit a high spin value. The rapid spin of Sagittarius A* suggests that a considerable portion of its mass originated from accretion. This knowledge contributes to our understanding of the history and structure of our galaxy and may even provide insights into the existence of intriguing objects such as wormholes.
Conclusion: The recent study on the spinning supermassive black hole Sagittarius A* highlights the fascinating phenomenon of the Lense-Thirring effect, where a rotating black hole alters space-time around it. By using the outflow method, physicists have determined the spin of Sagittarius A* and its implications for galaxy formation and evolution. This research provides valuable insights into the dynamics of black holes and their role in shaping the universe. Understanding the properties of black holes is crucial for unraveling the mysteries of our galaxy and beyond.
Leave a Reply