Search Here

A new groundbreaking study that provides new insight into galactic evolution has found that our milky way galaxy might have formed the inside-out. 

The researchers conducted a chemical analysis of stars throughout the Milky Way before reaching the unexpected conclusion. A team of researchers led by Gerry Gilmore, a Cambridge University professor of astronomy, tracked individual stars throughout the galactic disc and determined the pattern in which formation took place. 

The new findings also confirm the previous theories that regions of galaxy's disc were first to form.

They based their conclusion on the measurements of each star's "metallicity". Metallicity is the concentrations of chemicals other than hydrogen and helium. The two fundamental ingredients of stars are hydrogen and helium. Theoretically, older stars will have much lower quantities of elements other than hydrogen and helium, therefor they will also have lower metallicity. 

"The different chemical elements of which stars - and we - are made are created at different rates - some in massive stars which live fast and die young, and others in sun-like stars with more sedate multi-billion-year lifetimes," said Gilmore who is also a lead investigator on the Gaia-ESO Project in a press release.

Massive stars also have the tendency to lead a short life with a violent end. The violent end produces huge amounts of magnesium while going supernova. The deaths of such stars can also form a neutron star or in some cases black hole. 

"We have been able to shed new light on the timescale of chemical enrichment across the Milky Way disc, showing that outer regions of the disc take a much longer time to form," said study leader Maria Bergemann from Cambridge's Institute of Astronomy, according to RedOrbit. "This supports theoretical models for the formation of disc galaxies in the context of Cold Dark Matter cosmology, which predict that galaxy discs grow inside-out."

Researchers also noted that the work provided more detailed regarding so-called "double structure" in the Milky Way's disc. 

The findings have been detailed in an article published in Astronomy and Astrophysics.