The little Magellan Clouds (SMCs), a dwarf galaxy that is orbiting near our own Milky Way, appear to satisfy a rather dramatic ending.
That is the conclusion of a new study published in Astrophysical Journal Supplement Series astronomers have tracked over 7,000 large stars in SMC. Each one is more than eight times the size of our sun.
These star heavyweights burn a short life that lives bright and fast, providing clues about their own movements as well as their turbulent gas clouds.
And what researchers found was impressive. This former codbone universe’s neighbor is torn apart quite badly by the gravity of the large Magellan Cloud (LMC).
“SMCs are interacting galaxies that are coupled to the LMC by gravity.” Satoya Nakano the first author of the study said BBC Science Focus. “The stars on the side of the SMC near the LMC experience stronger gravity and are moving towards the LMC, but the stars experience even weaker pulls.”
This gravitational tug of war slowly pulls the SMC apart with possible nudges from our own Milky Way approaching about 200,000 light years away.
So why is this important?
For one, the team discovered that the SMC was not rotating the way astronomers had assumed. Spiral galaxies like our own usually rotate with stars and gas processing around the central axis. But not all galaxies are – and SMC may be one of them.
“The question of when rotational motion appears in galaxies is a very interesting topic among researchers,” Nakano said.
“SMC was considered a rotating galaxy, but this study shows that it is not actually rotating. It suggests that if even a nearby galaxy like SMC is misinterpreted, it requires much more attention when assessing galaxy rotations further away.”
And SMC is very close by space standards. Just 200,000 light years away, it is more than ten times closer to Andromeda, the nearest largest galaxy.
The lack of rotation not only changes our understanding of SMC’s structure, but also allows us to discard estimates of mass.
“The SMC is not rotating, so historical estimates of its mass may be incorrect.” Professor Tahara the author of another study said BBC Science Focus.
“The estimates of mass were born from previously estimated rotational motions. However, if these are not reliable, the estimates need to be revised. Without this, we cannot predict the future existence of SMC.”
Nakano and Tahara hope that detailed simulation observations to model the fate of the galaxy open the door. But for now, the future appears to be far from bright.
About our experts
Satoya Nakano is a doctoral candidate from the Faculty of Physics, Graduate School of Science, Nagoya University, Japan.
Tahara Sword He is an associate professor at Nagoya University Graduate School of Science, Japan. His research is Publications of the Japanese Astronomical Association, Astrophysical Journal and Astronomy and Astrophysics.
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Source: www.sciencefocus.com