A University of California-Santa Cruz astrophysicist has created basketball-sized models of star farms, revealing features hidden in traditional renderings and animations.
Stellar nurseries are huge clouds of gas and dust in which new stars can form under the influence of the gravity of denser regions known as “lumps”. While false-color photographs and concept art of stellar nurseries are well-known images in popular science, Professor Nia Imara was interested in creating stellar nursery models that captured the complex structural details of these formations.
Imara created the models using data from simulations of star-forming clouds and an advanced 3D printing process in which the fine-scale densities and gradients of the clouds are embedded in a transparent resin. The resulting models are smooth, polished spheres about 8 cm in diameter, in which the clouds appear as delicate, swirling clumps and filaments.
“We wanted an interactive object to help us visualize those structures where stars are formed so that we can better understand the physical processes,” Imara said.
Imara, an accomplished autodidact, and astrophysicist said the idea is an example of science imitating art: “Years ago I sketched a portrait of myself touching a star. Later, the idea just clicked. Star formation within molecular clouds is my area of expertise, so why not try to build one?”
Imara and her collaborators developed a series of nine simulations representing different physical conditions within molecular clouds, then turned the data from the simulations into physical objects via high-resolution photorealistic 3D printing using different materials. While traditional extrusion-based 3D printing can only produce solid objects with a continuous outer surface, they used an inkjet-like process to deposit tiny droplets of opaque resin at precise locations in a surrounding volume of transparent resin, allowing them to create the diffuse shapes. build in fine detail.
Co-author Dr. John Forbes said, “Only aesthetically they are really great to look at, and then you start noticing the complex structures that are incredibly difficult to see with the usual techniques of visualizing these simulations.”
For example, plate-like or pancake-shaped structures are difficult to distinguish in two-dimensional slices or protrusions because a section through a plate simply looks like a filament. Within the spheres, Forbes says, are visible sheets of tiny filaments, which is “baffling” from the perspective of an astrophysicist trying to understand these evolving structures.
The models also show structures that are more continuous than they would appear in two dimensions. Imara explains, “If you’re swinging something through space, you might not realize that two regions are connected by the same structure, so having an interactive object that you can rotate in your hand makes it easier for us to detect these continuities.”
The simulations on which the models are based are designed to investigate the effects of three physical processes that influence the evolution of molecular clouds: turbulence, gravity and magnetic fields. By playing with these variables, such as the strength of the magnetic fields or how fast the gas is moving, the simulations show the impact on the morphology of substructures associated with star formation.
Stars tend to form in clumps and cores located at the intersection of filaments, where the density of gas and dust is great enough for gravity to take over and start star formation. Imara said, “We think the spins of these newborn stars will depend on the structures they form in; stars in the same filament will ‘know’ about each other’s spins.”
The researchers say the models make it possible for anyone to get an idea of how factors such as gravity affect the conditions of star formation. They hope they will serve as tools for education and outreach; Imara plans to use them in an astrophysics course she will be teaching this fall.
In the future, they could try to absorb additional information by exploring the use of color and 3D printing to display observational data from nearby molecular clouds, such as those in the constellation Orion.