How much does a black hole change in a year? Scientists may now have an idea, after taking a fresh look at the very first black hole to be imaged – the supermassive black hole M87*, located at the center of the Messier 87 galaxy. Having previously observed the bright halo of matter whipping around the black hole at almost the speed of light, the team will now look even more closely at the movement of material within that halo.
The new observations, made with the Event Horizon Telescope (EHT), provide the most detailed, real-time view yet of how matter swirls around supermassive black holes. The findings were published in the journal on January 22 Astronomy and astrophysics.
As matter falls into a black hole, it also circles around it like water flowing down a drain. The way this ‘accretion disk’ of infalling matter spins can tell scientists a lot about a given subject black hole — for example, its size and orientation in space. It also provides insight into how gas and dust behave near the event horizon, the boundary beyond which nothing, not even light, can escape.
In their new study, the researchers used data collected from M87* in 2017 and 2018 to image the black hole’s accretion disk and create computer models. They noticed that the brightest part of the disk had rotated 30 degrees from year to year.
Related: The supermassive black hole in the Milky Way is spinning incredibly fast and at the wrong angle. Scientists may finally know why.
These new observations confirm that M87*’s rotation axis points away from Earth. Moreover, the outer plasma ring likely rotates against the spin of the black hole, the team found.
‘When gas spirals into a black hole from far away, it can flow in the same direction that the black hole is spinning, or in the opposite direction’ Leon Sosapanta Salasan astronomer at the University of Amsterdam and co-author of the new study, said in a statement. “We have determined that the latter case is more likely.” This supports scientists’ existing models of how matter moves around supermassive black holes. The study is a milestone in our understanding of how the matter swirling around a black hole ebbs and flows. “This work highlights the transformative potential of observing black hole environments as they evolve over time,” study co-author Hung-Yi Puan assistant professor at National Taiwan Normal University said in the statement. The research also helped confirm that the supermassive black hole is about 6.5 billion times the mass of our Sun.
Ultimately, this kind of research will deepen our understanding of the evolution of the cosmos. Supermassive black holes are at the heart of every major galaxy we know; Learning their secrets could help us determine how galaxies form and die.
