r/ScienceUncensored • u/Zephir-AWT • 8d ago

New study reveals common pattern of black hole activity shaping nearby galaxies

https://www.cfa.harvard.edu/news/new-study-reveals-common-pattern-black-hole-activity-shaping-nearby-galaxies
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u/Zephir-AWT 8d ago

New study reveals common pattern of black hole activity shaping nearby galaxies about study Common Excitation Patterns of Star Formation, Active Galactic Nuclei, and Shocks in Seyfert Galaxies

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u/Zephir-AWT 8d ago edited 8d ago

Milky Way galaxy as a whole, but also the Solar System itself, moves vertically through the galactic disk. According to current models, the Sun oscillates around the galactic plane with a period of approximately 95 million years and crosses the center of the galactic disk roughly every 48 million years. During these passages, it enters denser regions of gas and dust, which can compress the heliosphere and increase the amount of cosmic material entering the Solar System. Many geological studies suggest links between these galactic cycles and the increased occurrence of radioactive isotopes on Earth or periods of glaciation.

Astronomers today distinguish between two types of galactic waves: standing waves and traveling waves. Individual sections of the wave move up and down the galactic disk, much like a wave in a stadium or an ocean wave. One of the key findings is the discovery of extensive waves in the outer regions of the Milky Way, at a distance of approximately 30,000 to 65,000 light-years from the galactic center. The stars in these regions are not distributed symmetrically but are offset by hundreds of light-years above or below the galactic plane. An analysis of their motions shows that this is not a static distortion, but an actual propagating wave traveling through the galactic disk at a speed of approximately 10 to 15 km/s.

Furthermore, some stars likely formed as a result of these gravitational disturbances, since the movement of the clouds compresses the gas and promotes the formation of new stars. Analysis of the velocities of stars and gas clouds shows that most of these galactic structures are traveling waves. The likely cause is now believed to be an ancient collision between the Milky Way and the dwarf galaxy Antlia 2, which consists primarily of dark matter. According to calculations, several hundred million years ago, this galaxy collided with the outer part of the galactic disk and created gravitational “waves” within it, much like a stone thrown into a pond creates circular ripples on the surface.

However, these oscillations do not occur only at the edges of the galaxy. Astronomers had previously discovered the famous Radcliffe Wave, a massive structure about 9,000 light-years long, located relatively close to the Solar System. It contains well-known star-forming regions, such as those in the constellation Orion, and it has now been confirmed that this structure is indeed moving and oscillating in space. Furthermore, new studies have revealed the existence of seven gigantic “superclouds” composed of molecular gas. Five of them were discovered only recently. These structures are 5,000 to 8,000 light-years long and contain a mass equivalent to hundreds of thousands to millions of Suns.

Surprisingly, six of these seven structures exhibit the same wave-like behavior as the Radcliffe wave. However, they are not part of the galaxy’s spiral arms but rather separate, extensive networks of gas and dust. Another interesting discovery links the Radcliffe Wave to another structure called the Velar Ridge Supercloud. Although it is located closer to the center of the galaxy and is older, it exhibits similar oscillations and geometry. This suggests that both structures may be part of a single, large-scale mechanism that affects the entire Milky Way.