Sagittarius A* Emits Hot Wind Equivalent to 25,000 Suns, Explaining Dormant State

Scientists have detected a powerful hot wind emanating from Sagittarius A* (Sgr A*), the supermassive black hole at the center of the Milky Way galaxy, with an energy output equivalent to 25,000 Suns. This groundbreaking discovery offers a crucial explanation for why Sgr A* has long remained relatively quiet compared to the highly active black holes found in other galaxies. The findings indicate that the black hole is actively expelling gas, preventing it from consuming surrounding matter at a higher rate.

The detection, which culminated from five years of observations, was announced by researchers. As noted in a social media post, > "After five years of staring into the void, scientists caught our galaxy’s black hole blowing a hot wind worth 25,000 Suns." The post further elaborated, > "Turns out, instead of devouring everything, it’s been on a cosmic detox, venting gas and staying chill. Who knew even black holes needed a pressure release?"

The research was led by Mark Gorski and Elena Murchikova at Northwestern University, utilizing the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. Their meticulous mapping of the circumnuclear disk around Sgr A* revealed a cone-shaped region devoid of cold gas, which precisely aligned with X-ray emissions from hot matter. This direct observation provided compelling evidence of the hot gas ejection.

This substantial outflow acts as a vital "pressure release valve," expelling material that would otherwise fall into the black hole. This mechanism is key to Sgr A*'s relatively inactive state, where it does not produce the powerful jets characteristic of more active supermassive black holes. The energy required for this wind is too immense to be generated by nearby stars or supernovae, strongly suggesting its origin from Sgr A* itself.

Beyond the hot wind, other factors contribute to Sgr A*'s quiet nature. Studies using NASA's SOFIA observatory have indicated that strong magnetic fields near the black hole can channel gas into orbit around it rather than allowing it to fall in. While Sgr A* is currently dormant, it has shown past activity, including a brief, intense flare approximately 200 years ago, suggesting its quiet phases are part of a dynamic evolutionary process.

The discovery offers significant insights into the evolution of black holes and their host galaxies. Understanding the dynamics of this wind could help scientists determine the spin direction of Sgr A*, a crucial parameter that has been challenging to ascertain. Furthermore, these findings provide a clearer picture of how supermassive black holes influence their galactic environments and regulate processes like star formation by clearing out gas.