Astronomers detect signs of wind from Milky Way’s central black hole

The feature measures about three light-years long with a 45-degree opening angle and points directly back to the black hole. Researchers created the map using the Atacama Large Millimeter/Submillimeter Array in Chile and confirmed the presence of hot plasma with NASA’s Chandra X-ray Observatory.

A* contains roughly four million times the mass of the sun. For more than fifty years, scientists have expected the object to expel some material in the form of wind or jets, yet no recent evidence had been found. Earlier observations had detected signs of past eruptions dating back more than twenty thousand years. The new data indicate activity within a much more recent period.

How the wind was identified The cavity appears empty of cold gas while adjacent regions remain dense, a pattern consistent with hot gas pushing outward. One researcher compared the process to a hair dryer moving air through wet hair. The same study notes that the wind is weaker than outflows seen in other galaxies, which may explain why it had not been detected until instruments improved.

Researchers plan to extend the gas map to a wider area and to track the motion of clouds approaching the black hole to measure how much material it consumes.