Astronomers from the National Science Foundation's (NSF) NoirLab have found evidence of a mass migration of stars into the Andromeda Galaxy, one of the Milky Way's neighboring galaxies.
Star motions exhibit complex patterns indicating migratory history similar to the Milky Way. The new findings were attained using the NSF's NOIRLab program's Dark Energy Spectroscopic Instrument, which was mounted on Kitt Peak National Observatory's Nicholas U. Mayall 4-meter Telescope.
(Photo : AFP via Getty Images)
SPACE: Picture released 04 October 2006 by the European Space Agency shows one-half of the Hubble Space Telescope field of view with nine stars that are orbited by planets with periods of a few days.
7,500 Stars in Andromeda
The astronomers studied the motions of almost 7,500 stars in the inner halo of Andromeda, which is also known as Messier 31 (M31).
They found patterns in their positions and motions that indicated how these stars originated as a component of an earlier galaxy that joined M31 2 billion years ago.
Arjun Dey, an astronomer at NSF's NOIRLab and the lead author of the study, said that the latest analyses of the Milky Way's closest massive galactic neighbor, the Andromeda Galaxy, provide proof of a galactic immigration event in vivid detail.
"Although the night sky may seem unchanging, the Universe is a dynamic place. Galaxies like M31 and our Milky Way are constructed from the building blocks of many smaller galaxies over cosmic history," Dey said in a statement.
This investigation provides information on the past of our galaxy and our planetary neighbors.
During a galactic merger 8-10 billion years ago, most of the stars in the Milky Way's halo were created in another galaxy and eventually moved into our own, according to NOIRLab.
Milky Way's Past
Astronomers can gain insight into one of the most important historical occurrences in the Milky Way's past by examining the remnants of a comparable but more recent galaxy merger found in M31.
The team looked to DESI to learn more about the migration's past in M31. Tens of millions of galaxies and quasars in the local Universe can be mapped by the Dark Energy Survey Instrument (DESI) since it was built to determine the impact of dark energy on the Universe's expansion.
With the ability to measure the spectra of more than 100,000 galaxies per night, it is the most potent multi-object survey spectrograph in the world, according to NOIRLab. The advanced telescope was crucial in surveying the inner halo of Andromeda.
The team now intends to examine more of M31's peripheral stars using the unmatched capabilities of DESI and the Mayall Telescope to unveil its structure and immigration history in extraordinary detail.
The findings of the study were published in The Astrophysical Journal.
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