EVANSTON — Researchers reported on June 4 that they found evidence of a wind blowing from Sagittarius A*, the supermassive black hole at the center of the Milky Way. Observations show a cone-shaped gap near the black hole that is devoid of cold carbon monoxide.
Astrophysicist Lena Murchikova and astronomer Mark Gorski collected more than 100 hours of observations of the black hole over five years. They used the Atacama Large Millimeter/Submillimeter Array radio telescopes. Researchers used a new data processing method to detect materials 100 times fainter than previous limits and produce an image 80 times sharper.
Researchers concluded that the cone-shaped gap and earlier X-ray observations of hot gas in the region indicate a hot wind flowing outward from the black hole. Murchikova said, "We have never seen gentle breezes from black holes, but likely that is what they do most of their lives. Now, for the first time, we see this gentle breeze from the black hole." The black hole is currently consuming material at a minimal rate.
Gorski said, "Supermassive black holes throughout the universe live most of their time in a quiet state. So these findings tell us that even though most black holes are pretty quiet, they are still having an impact." Black hole winds can slow star formation, limit material accretion, or trigger star formation by compressing dust clouds.
Astrophysicist Rebecca Diesing said, "The potential discovery of a wind coming from Sagittarius A* is indeed a big deal. It would demonstrate that our supermassive black hole is not unique, that it produces a wind just like those in other galaxies." Diesing said that future observations could confirm the wind by measuring gas velocity or tracking changes in the void edges over time. Astronomers discovered the black hole in the 1970s.