Hydrogen gas flows outward like a river from the Large and Small Magellanic Clouds, two dwarf galaxies located on the edge of the Milky Way. The contents of the river, called the Magellanic Stream, have puzzled astronomers for decades.
But now, a team of researchers has been able to determine the positions of stars in the stream’s gas clouds for the first time, according to… Space.com website From his report. This discovery will not only help us better understand the evolution of the main stream galaxies, but it will also help us understand the distribution of matter in the Milky Way itself.
Astronomers at the Harvard-Smithsonian Center for Astrophysics discovered the stars using the 6.5-meter Magellan PADI telescope at Las Campanas Observatory in Chile. Using a detailed map of the Milky Way produced by the European Space Agency’s Gaia space telescope, the researchers looked at 200 stars located in the farthest part of our galaxy, in the direction of the Magellanic Stream.
They analyzed the spectrum of light from these stars, among other things, and found that 13 objects had the same chemical composition as the Magellanic Cloud. Measurements also indicated that these 13 stars could be between 150,000 and 400,000 light-years from Earth, which roughly corresponds to the distance of the Magellanic Stream.
Originally discovered in the 1970s, this stream extends over an area of the southern sky roughly the size of 300 full moons of Earth. However, sensitive equipment is needed to be able to detect it.
How could gas flow from there into the Milky Way?
Astronomers believe that the gas that makes up the stream was separated from the dwarf galaxies by the gravitational force of the Milky Way. New observations may reveal more about its nature and help us understand how it interacts with our galaxy. According to scientists, the stream now appears to be falling into the Milky Way Galaxy.
“With these results, we hope to significantly improve our understanding of the formation of the Magellanic Stream and the Magellanic Clouds, as well as their past and future interactions with our galaxy,” said Charlie Conroy, a professor of astronomy at the Harvard-Smithsonian Center. for Astrophysics (CfA).
Unlike the Magellanic Stream, clouds have been known to humanity since ancient times, and are clearly visible with the naked eye. However, astronomers still have many questions about the origin and history of the two galaxies that appear to be colliding with the Milky Way. Mapping and modeling the Magellanic Stream will help astronomers better understand the source galaxies whose past orbits they are thought to trace.
“The beauty of a huge stream of stars like the Magellanic Stream is that we can now do a lot of astrophysical investigations with it,” said Vedant Chandra, a PhD student in astronomy and astrophysics at the CfA and lead author of the study. “As our spectroscopic survey continues and we find more and more stars, we’re excited to see what other surprises the galactic ocean has in store for us.”
Scientists believe that as hydrogen gas enters the Milky Way Galaxy, it creates the right conditions for star formation. By analyzing the data, the researchers also found that the stream is almost twice as large as previously thought. This means that the Milky Way must be devouring a much larger amount of gas than previous calculations assumed.
“The Magellanic Stream is the main source of calories for the Milky Way, and it serves as breakfast, lunch and dinner for Galais,” said Carnegie Observatories employee Anna Bonacca. “Based on new, higher mass estimates for the Magellanic Stream, the Milky Way may eventually gain more kilograms than we initially thought.”
Worth reading:
