An international team of astronomers and astrophysicists has found evidence that the Small Magellanic Cloud is not one galaxy, but two galaxies one behind the other. A group of scientists wrote an article describing their work and published it on the preprint server arXiv. The Magellanic Clouds have long been known as two irregular dwarf galaxies that can be seen very close to each other in the Southern Hemisphere. Because of their size, they were called the Large Magellanic Cloud and the Small Magellanic Cloud.
In the late 1980s, evidence emerged that the Small Magellanic Cloud (SMC) was not one, but two dwarf galaxies. Researchers have found further evidence for this theory in a new paper. The research team first examined data from the European Space Agency’s Gaia Space Observatory, which allowed them to estimate the average speed of stars in different regions of the IMO. The scientists then examined data from the Galactic Australian Square Kilometer Array Pathfinder radio telescope in Western Australia, which allowed them to learn more about the interstellar medium in both the SMC and LMC.
Astronomers also analyzed APOGEE data from the Sloan Foundation and the NMSU telescope at Apache Point Observatory in New Mexico. After analyzing all the evidence, researchers discovered that the two “parts” of MMO differ in chemical composition. Scientists also discovered that the speeds of the two parts were different, with the faster part located in the closer part of the galaxy. The researchers found that the two pieces have approximately the same mass and are interacting with the LMC.
Scientists conclude that the combined data strongly suggests two unique galaxies, one located almost behind the other relative to Earth. This arrangement explains why the MMC was not recognized until recently as possibly consisting of two galaxies. The researchers also calculated that the closer of the two galaxies is about 199,000 light-years away, and the more distant is about 215,000 light-years away.