Physicists spend 3 months simulating the birth of a star

Astrophysicists have developed the first high-resolution 3D model of a gas cloud agglomerating to form a star, and it's amazing. It could take up to three months to simulate on the world's fastest supercomputer.

The "interstellar furnace" model (which stands for "star formation in a gaseous environment") allows users to fly through a colorful cloud of gas as it gathers to form stars around it. The researchers hope this visually stunning simulation will help them explore many of the unanswered questions about star formation, such as: Why is the process so slow and inefficient? What are the factors that determine whether a star is good or bad? Why do stars tend to cluster together?

The computational framework can simulate clouds of gas a hundred times larger than before, allowing scientists to model star formation, evolution, and dynamics while taking into account jets, radiation, winds, and even supernovae (nearby stellar explosions).

Claude Andre Faucher Giguel, an astrophysicist and senior author at Northwestern University, said in a statement, "Star formation is largely a central problem in astrophysics. It is a very challenging problem because of the range of physical processes involved. This new simulation will help us directly address fundamental questions that previously could not be answered definitively."

The formation of stars can take tens of millions of years. Stars rolling in from turbulent dust and gas gradually grow into protostars with mild light, then form stars like our Sun, which are formed from giant spheres of fused power. When studying the night sky, astrophysicists can glimpse brief snapshots of stellar evolution, but they need to use accurate simulations to observe and study the entire process.

Michael Gruden, a postdoctoral researcher at Northwestern University, said in a statement: "When we look at star formation in any given region, we see the scene of star formation frozen in time. Stars also form in dust clouds, so they are mostly hidden."

The model is so large that it could take up to three months to run simulations on one of the world's largest supercomputers located at the Texas Advanced Computing Center. It is this enormous size and computational complexity that makes the predictions of this new model more accurate, the researchers say.

People have been simulating star formation for decades, but Interstellar Forge is a technological leap forward," Grudick said. Other models can only simulate the tiny clouds that form stars, not entire clouds at high resolution. Without seeing the big picture, we missed a lot of factors that could have affected the star's performance."

The simulations start with a gas cloud floating in space (which is millions of times more massive than our sun). As time goes on, the gas cloud evolves. It rotates around itself, forms a larger structure, and then breaks off again. As a result of this creative destruction, the remaining small gas pockets are gravitationally attracted and become hotter and hotter due to constant friction, eventually becoming stars. The birth of a star culminates in two huge jets of gas ejected outward from its poles, penetrating the surrounding clouds.

Astrophysicists use simulations to understand the role of these gas jets in determining the mass of a star. When they run simulations without the jets, they get stars that are much larger than usual - about 10 times the mass of the Sun. When the jets recombine, they produce a more realistic-sized star with about half the mass of the Sun.

The jets disturb the flow of gas into the star," Grudick said. They essentially blow away gas that could eventually enter the star and increase its mass. One suspects this may be happening, but by simulating the whole system, we have a deep understanding of how it works."

By giving them a better understanding of star formation, the researchers also believe their simulations could provide some important insights into how galaxies propagate through the universe and how heavy elements, such as carbon and nitrogen, form key components of complex life.

If we can understand the formation of stars, then we can understand the formation of galaxies," Grudick said. By understanding the formation of galaxies, we can learn more about what the universe is made of. Understanding where we came from and where we fit in the universe ultimately depends on understanding the origin of stars."