How do Magnetic Fields Affect Star Formation and High-Energy-Density Lab Experiments?

The Pillars of Creation in the Eagle Nebula.
These are two Hubble space telescope images of the 'Pillars of Creation' in the Eagle Nebula. The left image captures a visible light view, showing an opaque cloud of gas and dust. On the right, near-infrared light penetrates much of the gas and dust, revealing stars behind the nebula and hidden away inside the pillars. (Images: via NASA, ESA, Hubble Heritage Project.)

The famous Pillars of Creation in the Eagle Nebulae — a star nursery — are believed to result from the hydrodynamic instabilities from magnetic fields that form when plasmas are exposed to high-intensity light from neighboring stars. Stretching roughly 4 to 5 light-years, the Pillars of Creation are a fascinating but relatively minor feature of the entire Eagle Nebula, which spans 70 by 55 light-years.

The nebula, discovered in 1745 by the Swiss astronomer Jean-Philippe Loys de Chéseaux, is located 7,000 light-years from Earth in the constellation Serpens. With an apparent magnitude of 6, the Eagle Nebula can be spotted through a small telescope and is best viewed during July. A large telescope and optimal viewing conditions are necessary to resolve the Pillars of Creation.

Something very similar to the process happening within the Pillars of Creation occurs — at a minute scale — when materials are imploded by converging laser beams during high-energy-density physics and fusion experiments at the Laboratory for Laser Energetics at the University of Rochester.

Magnetic fields are generated by the towering tendrils of cosmic dust and gas sit at the heart of M16, or the Eagle Nebula.
These towering tendrils of cosmic dust and gas sit at the heart of M16, or the Eagle Nebula. (Image: via NASA, ESA, and the Hubble Heritage Team (STScI / AURA))

The aptly named Pillars of Creation, featured in this stunning Hubble image, are part of an active star-forming region within the nebula and hide newborn stars in their wispy columns. Although this is not Hubble’s first image of this iconic feature of the Eagle Nebula, it is the most detailed. Blue colors in the image represent oxygen, red represents sulfur, and green represents nitrogen and hydrogen. The pillars are bathed in scorching ultraviolet light from a cluster of young stars outside the frame. The stars’ winds slowly erode the towers of gas and dust.

Hussein Aluie, associate professor of mechanical engineering at Rochester’s Hajim School of Engineering & Applied Sciences, said:

“You shine the lasers, you evaporate mass off of the surface, and push everything radially inwards, and you have these hydrodynamic instabilities that have modulations similar to the Pillars.”

Plasmas undergoing instabilities generate magnetic fields

To what extent do plasmas undergoing instabilities generate magnetic fields, and how do those magnetic fields further influence plasma instabilities? Aluie said:

“It is well known that magnetic fields can strongly impact how plasmas behave, but the mechanisms for self-generation and amplification of magnetic fields in different types of plasma continue to be a mystery.”

Professor Hussein Aluie posing outdoors.
Hussein Aluie, Associate Professor, Department of Mechanical Engineering Staff Scientist, Laboratory for Laser Energetics, University of Rochester. (Image: University of Rochester)

With funding from a US$390,000 National Science Foundation grant, Aluie will address this mystery with co-PI Riccardo Betti, LLE’s chief scientist and Robert L. McCrory Professor, and Fernando Garcia-Rubio, assistant scientist at the LLE and in Aluie’s Turbulence and Complex Flow Group, who has been developing the theory for this work. The goal is to identify the primary mechanisms by which magnetic fields are self-generated in irradiated plasmas subject to instabilities. The work will involve theoretical analysis and numerical simulations. Aluie said:

“Based on previous research that we and others have done, and hope to develop in more depth, we know that these magnetic fields, even if they are initially small in strength, grow quickly. They affect the way heat moves around the surface of the plasma and evaporates mass, which alters the way the instability forms. And in the case of fusion experiments, it alters the way the target becomes unstable.”

A better understanding of this process could help scientists move closer to achieving fusion as a source of unlimited energy and a better understanding of the formation of nebulae and other astrophysical bodies, Aluie says.

Provided by the University of Rochester [Note: Materials may be edited for content and length.]

Follow us on TwitterFacebook, or Pinterest

RECOMMENDATIONS FOR YOU