Astronomers have confirmed the presence of a strong cosmic wind originating from Sagittarius A*, the supermassive black hole at the galaxy’s core.
This significant finding offers the clearest insight so far into how this massive object influences its nearby environment, possibly resolving a space science mystery that has persisted for half a century.
While black holes are renowned for their intense gravitational pull that draws in nearby matter, they also eject powerful jets of material into space.
Theoretical physicists have long predicted that as gas and matter spiral into a black hole at nearly the speed of light, the enormous energy produced causes some of the hot material to be expelled as cosmic winds. However, this phenomenon had not been directly observed from Sagittarius A* until recently.
“Unless a black hole exists in a perfect vacuum, it must blow a wind somehow,” said Mark Gorski of Northwestern University, who co-led the study. “With new observations, this is the first time we’ve had a clean enough view to see the wind’s imprint.”
The breakthrough was made possible by five years of deep-sky observations from the ALMA observatory in Chile. The team produced the clearest image to date of the cold molecular gas around the black hole.
Using advanced image processing to eliminate the black hole’s intense radio emissions, they uncovered a large, cone-shaped cavity entirely lacking cold gas within three light-years of the center. The researchers deduced that a hot, energetic wind emanating directly from the black hole was likely responsible for creating this vast void.
Data from NASA’s Chandra X-ray Observatory confirmed the findings, showing bright X-ray emissions slotting perfectly into the exact region where the cold gas was missing.
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Astrophysicists estimate that this cosmic wind has been active for at least 20,000 years. The discovery also confirms that our galaxy’s central black hole is currently in a quiet phase, unlike the active “fireworks stage” seen in other galaxies.
“Sagittarius A* finally gives us a window into the life of a black hole in this quiet state,” said co-lead researcher Elena Murchikova, noting that the findings prove our galaxy’s black hole behaves consistently with theoretical models.