Northwestern Detects 1-Parsec Wind From Sgr A*, Solving 50-Year Mystery
Updated
Updated · CBS New York · Jun 4
Northwestern Detects 1-Parsec Wind From Sgr A*, Solving 50-Year Mystery
3 articles · Updated · CBS New York · Jun 4
Summary
Five years of ALMA observations let Northwestern researchers identify a hot outflow from Sagittarius A* that carved a one-parsec cavity about 45 degrees wide near the Milky Way’s center.
A new calibration method removed interference from the black hole’s radio emission, producing maps 100 times deeper and 80 times sharper than earlier attempts that had failed to spot any current wind.
The cavity contains no cold molecular gas, a signature the team said only an energetic black-hole wind could create; stellar winds in the region lacked enough power to sweep it that cleanly.
Chandra X-ray data matched the gas-free cavity, reinforcing the finding that Sgr A* has likely driven a relatively quiet wind for at least 20,000 years.
The result, published in The Astrophysical Journal Letters, resolves a long-standing anomaly because black-hole models have long held that any non-isolated black hole must blow some kind of wind.
Our galaxy's black hole has a 'hot breeze.' Does this celestial wind create vast, uninhabitable 'dead zones' for alien life?
Our galaxy's central black hole was thought to be a quiet giant. Why is it now seen ejecting more matter than it consumes?
Discovery of a Hot Wind from Sagittarius A*: Unveiling the Missing Link in Black Hole Feedback and Galactic Evolution
Overview
Astronomers have confirmed the existence of a hot wind blowing from Sagittarius A*, the supermassive black hole at the center of our galaxy. This discovery is a major step in understanding how black holes affect their surroundings. Detecting the wind was extremely challenging because astronomers had to look through the dense plane of the Milky Way, which is packed with gas, dust, and ionized structures that block visibility. Years of careful observations and advanced imaging techniques finally revealed the faint signals of this wind, providing new insights into the dynamic environment around Sagittarius A*.