Surprising elements have been spotted in strangely hot ‘teen’ galaxies
Did you go through a heavy metal phase when you were a teenager? If yes, then you may have something in common with “teenage” galaxies. They are also interested in the heavy metal: nickel. This surprising discovery is just one of many among galaxies that formed in the first 3 billion years after the Big Bang.
The team combined the light spectra of 23 of the 33 teenage galaxies observed last summer to create a composite image of an ordinary young galaxy. This allowed them to highlight some common compositional ideas. Having eight elements literally shined. Hydrogen, helium, nitrogen, oxygen, silicon, sulfur, argon and nickel were discovered.
“Never in my wildest dreams did I imagine we would see nickel,” lead author Alison Strom of Northwestern University said in a statement. “Even in nearby galaxies, people don’t notice this. There has to be enough elements in the galaxy and the right conditions to observe them. No one ever talks about observing nickel. The elements have to be gas glowing for us to be able to see them. So, for us to be able to Seeing nickel, there may be something unique about stars within galaxies.
But it wasn’t just the presence of nickel that was unusual. Galaxies tend to be at higher temperatures. The hot pockets of teenage galaxies have a temperature of more than 13,350 °C (24,062 °F), much higher than the current universe’s temperature of about 9,700 °C (17,492 °F).
These galaxies were different. We want to understand those differences and how they change over time. Together, this will provide a more accurate picture of the evolution of galaxies over the epochs of the universe.
“These teenage years are really important because that’s when the most growth occurs,” Strom said. “By studying this, we can begin to explore the physics that makes the Milky Way look like the Milky Way — and why it might look different from its neighboring galaxies.”
The observations were made by the James Webb Space Telescope as part of the CECILIA (Chemical Evolution Constrained Using Ionized Lines in Interstellar Aurora) survey. The back name honors Cecilia Payne-Gaposchkin, one of the first women to earn a doctorate in astrophysics. Her research allowed humanity to learn about the elements found in stars and galaxies.
“Naming our JWST survey after Cecilia Payne-Gaposchkin was intended to honor her pioneering studies on the chemical composition of stars,” explained Gwen Ruddy, a scientist at Carnegie Observatories who co-led the Cecilia survey with Strom. “Alison and I realize that our work revealing the chemistry of these very early galaxies builds on their legacy.”
The study was published in The Astrophysical Journal Letters.