Saturday, October 26, 2024

Massive stars born from violent cosmic collapse: New process of star formation challenges turbulent core model

Overview of an example high-mass starless clump (HMSC) G022.5309-0.1927
Credit: The Astrophysical Journal Letters (2024). DOI: 10.3847/2041-8213/ad7b08

Controlled chaos is a key part of forming massive stars. An international team of astronomers has observed evidence that massive stars can be born from rapidly collapsing clouds of gas and dust, challenging long-held assumptions about star formation.

The heavy elements that heavy stars create, like iron or calcium, are scattered across the universe when they collapse as supernovas. These elements become part of new stars, new planets—and everything in between.

The research team analyzed 44 high-mass starless clumps (HMSCs) using the Green Bank Telescope (GBT). The scientists discovered that nearly all of these stellar nurseries (43 out of 44) are in a "sub-virial" state, meaning they lack sufficient internal energy to resist gravitational collapse.

This research, led by Prof. Ke Wang of Peking University's Kavli Institute for Astronomy and Astrophysics, contradicts the prevailing turbulent core model, which assumed these regions were in equilibrium before star formation began. The results are published in The Astrophysical Journal Letters.

As Wang explains, "Instead, the data we saw suggests a more dynamic process involving rapid collapse. HMSCs are undergoing an almost free-fall collapse, explaining why genuine massive prestellar cores are so rarely observed. To prevent collapse, these regions would require unusually strong magnetic fields. These fields are the invisible scaffolding of the universe, holding things up in ways astronomers are just beginning to understand."

This research used the Radio Ammonia Mid-Plane Survey (RAMPS) survey on the GBT. This survey focuses on 24 square degrees of the Galactic Plane, and provides valuable data for understanding the formation of high-mass stars, the structure and composition of molecular clouds, and the dynamics and evolution of our galaxy.

This discovery provides crucial insight into the birth of massive stars, which are responsible for creating the heavy elements essential for life. "The universe is a giant puzzle, and surprising findings like this are a sweet part of life as an astronomer," adds Fengwei Xu, co-author of the paper.

Existing theoretical models will need to adapt to account for this more violent and rapid star formation process. The team plans to use high-resolution telescopes like the Atacama Large Millimeter/submillimeter Array to further confirm their findings and probe the earliest moments of massive star formation, and future magnetic field measurements within HMSCs.




More information: Ke Wang et al, Massive Star Formation Starts in Subvirial Dense Clumps Unless Resisted by Strong Magnetic Fields, The Astrophysical Journal Letters (2024). DOI: 10.3847/2041-8213/ad7b08

Journal information: Astrophysical Journal Letters

Provided by National Radio Astronomy Observatory



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