Our home Milky Way doesn’t look particularly strange as a galaxy. moderately sized spiral some twists suggest destructive past.
But astronomers have discovered a peculiarity never seen before in any galaxy studied: the Milky Way is too large for its surroundings.
Specifically, it seems too large for the neighborhood in which it is located. local seatThis flat arrangement of galaxies shares similar velocities and relatively empty Spaces called voids on both sides.
As an example of a “wall of space”, our local sheet is local void In one direction from the southern void.
The relationships between galaxies in the local sheet seem to have a strong influence on their behavior.For example, their similar speed Proportional to the expansion of the universe. Outside the space wall environment, these velocities would have a much wider range.
To determine the effects of the environment on the galaxy around us, a team of astronomers led by Miguel Aragon of the National Autonomous University of Mexico conducted an analysis using simulations of a project called . Illustrated TNGwhich models the physical universe.
They didn’t expect to find anything particularly unusual.
“The Milky Way is special in a way” Aragon says“Earth is clearly a special entity, the only one we know is home to life. But it’s not the center of the universe, not even our solar system. It’s just an ordinary star in a billion stars, and even our own galaxy is just one of billions of other spiral galaxies in the observable universe.”
But a simulation of space spanning about a billion light-years, containing millions of galaxies, reveals a different picture. Within the cosmic wall structure, there are only a handful of galaxies as massive as the Milky Way.
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“The Milky Way has no particular mass or type. There are many loosely similar spiral galaxies.” Astronomer Joe Silk says Institut d’Astrophysique de Paris, Sorbonne University, France.
“But given its surroundings, it’s rare. If you can easily see the nearest dozen or very large galaxies in the sky, they all lie roughly on a ring embedded in the local sheet.” You see, it’s a bit. Our new discovery is that the walls of other galaxies in the universe, like the local sheet, rarely have galaxies as massive as the Milky Way inside. It means you can see it.
The team’s analysis did not consider the Milky Way’s largest neighbor, Andromeda. A feature of the local sheet and part of the same cosmic wall, this is a galaxy similar in size to the Milky Way. Their conclusion still applies, because it is even rarer for him to have two strongmen in the cosmic walls.
However, research may need to consider our local environment when studying the Milky Way, rather than assuming that our home hangs in an average place in the universe. It emphasizes that it cannot
The team’s simulations only considered the context of the Milky Way within the walls of space, so perhaps future studies could explain more galaxies within the local group. unusual arrangement of satellite galaxies, their peculiar lack around the Milky Way.
“Be careful… choose properties that are considered ‘special'” Astronomer Mark Neirink says of the Basque Science Foundation of Spain
“If we add extraordinarily restrictive conditions to the galaxy, such as the galaxy must contain papers written about it, it would undoubtedly be the only such galaxy in the observable universe. But this thinks it’s “too big for the wall” enough to exclaim that the property is physically meaningful, observationally relevant, and truly special. ”
This research Monthly Notices of the Royal Astronomical Society.
