In a discovery that draws an unexpected parallel between holiday cooking and celestial phenomena, astronomers have identified a crucial force that helps galaxies efficiently form new stars—much like the lid of a pressure cooker helps create the perfect Christmas pudding.
Published in Monthly Notices of the Royal Astronomical Society | Estimated reading time: 4 minutes
An international research team led by Dr. David Clements of Imperial College has uncovered evidence of magnetic fields deep within merging galaxies, solving a long-standing astronomical puzzle about efficient star formation. This discovery, made in a system known as Arp220, reveals how nature creates ideal conditions for cooking up new stars in galactic kitchens.
“This is the first time we’ve found evidence of magnetic fields in the core of a merger,” said Dr. Clements, “but this discovery is just a starting point. We now need better models, and to see what’s happening in other galaxy mergers.”
The research team utilized the Submillimeter Array (SMA) on Maunakea in Hawaii to peer into Arp220, one of the brightest objects in the extragalactic far-infrared sky. This remarkable system emerged from the collision of two gas-rich spiral galaxies, triggering intense star formation in its nuclear regions.
Drawing an illuminating parallel with holiday cooking, Dr. Clements explains that just as a pressure cooker needs its lid and weight to maintain the perfect conditions for steaming a pudding, merging galaxies require magnetic fields to create ideal conditions for star formation. Without these magnetic fields, the intense energy from star formation could cause the gas needed to form new stars to disperse too quickly, much like an overheating pressure cooker boiling over.
The discovery could explain why some galaxies form stars more efficiently than others. In particular, it may help explain the phenomenon of starbursts—periods of extremely rapid star formation that seem to defy the normal relationship between star formation rate and galactic mass. The magnetic fields appear to act as a binding force, holding star-forming gas together longer and resisting its natural tendency to expand and dissipate when heated by young, hot stars or supernovae.
Glossary
- Starburst
- A period of extremely rapid star formation in a galaxy, occurring at rates higher than typical star-forming galaxies.
- Ultraluminous Infrared Galaxy
- A galaxy that emits exceptionally high amounts of infrared radiation, often due to intense star formation or active galactic nuclei.
- Far-infrared Sky
- The cosmic background radiation composed of integrated light from distant galaxies’ dust emissions, representing about half of all starlight.
Test Your Knowledge
What is the name of the galaxy system where researchers discovered the magnetic fields?
The magnetic fields were discovered in Arp220, a system of two merging galaxies that is one of the brightest objects in the extragalactic far-infrared sky.
How does the pressure cooker analogy relate to star formation?
Just as a pressure cooker needs its lid and weight to maintain cooking conditions, galaxies need magnetic fields to maintain the right conditions for star formation and prevent the gas from dispersing too quickly.
What role do magnetic fields play in the star formation process of merging galaxies?
Magnetic fields act as a binding force that holds star-forming gas together longer, resisting its tendency to expand and dissipate when heated by young stars or supernovae, thus enabling more efficient star formation.
Why is this discovery significant for our understanding of starburst galaxies?
The discovery helps explain why starburst galaxies can form stars more efficiently than normal galaxies, potentially resolving the puzzle of why they deviate from the typical relationship between star formation rate and galactic mass.
Enjoy this story? Subscribe to our newsletter at scienceblog.substack.com.