Dr. Sven Buder, from the ARC Centre of Excellence for All-Sky Astrophysics in 3 Dimensions (ASTRO 3D) and the Australian National University (ANU), said even though the Milky Way is the Earth's home galaxy, it remains unclear how it formed and eventually evolved.
As specified in a Cosmos report, Australian researchers recently examined the light in the Milky Way from hundreds of thousands of stars to determine which ones originated from within it and which ones formed in other galaxies and were blended into ours long, long time ago.
The Milky Way had eaten up lots of tinier galaxies, but until recently, there was no sufficient evidence to support it, said Buder, the first author of the study.
That is because images of the star in the Milky Way look the same, whether they originated inside or outside the galaxy and before they merged into the galaxy.
600,000 Stars Examined
In the study published in the Monthly Notices of the Royal Astronomical Society, the researchers examined the light from stars to help scientists better understand what went in to create the Milky Way seen today.
The research team from the Galactic Archaeology with HERMES or GALAH Survey used the largest optical telescope of Australia, the Anglo-Australian Telescope (ATT), to collect the light from over 600,000 stars and spit it with the High Efficiency and Resolution Multi-Element Spectrograph or HERMES instrument.
Similar to the manner water droplets in the atmosphere are splitting white light into its components to create rainbows, the study investigators divided the light into its different wavelengths to get 600,000 stellar spectra signatures.
Each comprises specific bands of light corresponding to the discharge of a spectrum of various chemical elements that act like small barcodes that differ according to the chemical composition of a star.
A new Australian study has analysed the light from 600,000 stars in the Milky Way to identify which ones originated within it, and which formed in other galaxies and were blended into ours in the distant past. “Although the Milky Way is our home galaxy,... https://t.co/vIaxv8ZHr0
— Cosmos (@CosmosMagazine) February 24, 2022
'Stellar Barcodes'
By scanning the said "stellar barcodes," the research team was able to measure how abundant 30 elements - iron, sodium, manganese, and magnesium - were and how they occurred in various concentrations depending on where the star was born, Buder explained.
This approach, also called chemical tagging, looks at the composition of a percentage of iron, manganese, sodium, and magnesium to determine if a star formed within the galaxy or was absorbed from a satellite galaxy.
This early phase in rebuilding the early Milky Way provides an understanding of the size of the galaxies it consumed in its early phases.
It could answer questions as well, about many of its special features, for instance, the galaxy's two distinct groups of stars in the disc that's seen as the "milky band in the sky."
Milky Way Spread Out Throughout the Night Sky
The Milky Way spread out throughout the night sky is a "familiar sight," and when one looks at it, they are actually staring into the center of the galaxy with its billions of stars.
Unknown to many, one is looking at two-star populations, one much older than the other, according to Buder. He added that the old stars have moved and thus, they look like they bulge out of the Milky Way's main plane, while the younger stars form a much simmer band in the plane.
However, it remains unknown why this has happened. The latest findings of the remains of gigantic, galactic collisions may contribute to such insight.
Related information about the Milky Way is shown on the Science Channel's YouTube video below:
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