Distant 'teenage galaxies' surprise astronomers with unexpected heavy elements - Space.com

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The deeper we look into space, the further back in time we see. Light emanating from some of the younger galaxies in our universe has to travel for billions of years to reach us, getting picked up by our instruments, rich with information from the cosmic dawn. And not only can this light tell us where we have come from, but where we might be headed.

To understand the evolution of several of these early universe, "teenage" galaxies, a Northwestern University-led team of astrophysicists have inspected data from the James Webb Space Telescope (JWST), which gazed back to realms that formed just two-to-three billions years after the Big Bang.

The observations have thrown up some intriguing surprises.

Specifically, the team analyzed results from the Chemical Evolution Constrained using Ionized Lines in Interstellar Aurorae (CECILIA) Survey to find that, not only do these galaxies appear hotter than expected, but they also seem to host heavy elements, like nickel.

A black and white image showing various galaxies studied with a diagram at the bottom indicating what elements were identified within. — Light from 23 distant galaxies, identified with red rectangles in the Hubble Space Telescope image at the top, were combined to capture incredibly faint emission from eight different elements, which are labelled in the JWST spectrum at the bottom. Although scientists regularly find these elements on Earth, astronomers rarely, if ever, observe many of them in distant galaxies. (Image credit: Aaron M. Geller, Northwestern, CIERA + IT-RCDS )

The researchers focused on 33 distant galaxies for a continuous 30 hour period. They then combined wavelengths of light collected from 23 of those galaxies to create a composite picture of what's happening in these structures — these spectra contain clues regarding things like their average temperatures and what elements might be lurking within.

"This washes out the details of individual galaxies but gives us a better sense of an average galaxy. It also allows us to see fainter features," Allison Strom, lead author of the study and assistant professor of physics and astronomy at Northwestern University, said in a statement.

The composite picture of the galaxies contained eight identifiable elements: Hydrogen, helium, nitrogen, oxygen, silicon, sulfur, argon and nickel. While the lighter elements were expected, the presence of nickel, which is heavier than iron in the periodic table, came as somewhat of a surprise.

"Never in my wildest dreams did I imagine we would see nickel," Strom said.