According to a new study, our galactic home, the Milky Way, may not be a regular spiral galaxy, as considered until now.
Specialists used their knowledge of the Milky Way and its surroundings in creating models which could help further our understanding of the rest of the Universe. However, as pointed out by the research team, these models will likely not hold if their base galaxy is proven to be an oddity.
The Milky Way, Not So Run-of-the-Mill, or Perhaps Totally Normal
Scientists have long since been studying our home galaxy, though there is still much to be learned about it. Our solar system was noted to be situated on the outer edge of this spiral armed galaxy.
Besides it, this gigantic galaxy also hosts billions of other stars, as well as a number of other, smaller satellite galaxies that surround it. Scientists analyze these smaller satellite galaxies to understand their host galaxy better.
However, according to a new study on the matter, this is also where the discrepancies arise. Early research results seem to suggest that the Milky Way may, or may not be, a typical galaxy.
The satellite galaxies of some of the Milky Way’s “siblings” – massive galaxies comparable in their environment and luminosity – are still seemingly very active. They were noted to be actively producing new star.
However, the Milky Way’s satellites appear to be rather “tranquil” and also “mostly inert”. This is according to the results of the SAGA (Satellites Around Galactic Analogs) Survey.
“The SAGA Survey aims to determine dwarf galaxy satellite systems around 100 Milky Way analogs,” as stated on the SAGA website.
Eight sibling galaxies have revealed some 16 satellite galaxies. The Sloan Digital Sky Survey detected another 13 satellite galaxies, which brings the total currently known number to 29.
The SAGA Survey reported studying only eight of time, so far. As such, current research findings are still preliminary, and cannot yet be used to reach a firm conclusion.
However, the survey team is looking to analyze another 17 satellite galaxies over the following two years. It will be doing so to try and establish whether the Milky Way is an “outlier” or “totally normal”.
“Our work puts the Milky Way into a broader context. The SAGA Survey will provide a critical new understanding of galaxy formation and of the nature of dark matter,” states Risa Wechsler, a study co-author, Stanford University astrophysicist.
The paper with the preliminary study results was published in the journal Astrophysical Journal.
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