by A river of hydrogen gas flows out of the Large and Small Magellanic Clouds, two dwarf galaxies located on the edge of the Milky Way. The contents of this river, known as the Magellanic Stream, have puzzled astronomers for many years. But now, for the first time, a team of researchers is able to find stars within the gaseous clouds of the stream. The discovery will not only help them better understand the evolution of the stream’s home galaxies, but also the distribution of matter in the Milky Way itself.
The astronomers, from the Harvard-Smithsonian Center for Astrophysics, discovered the stars using the 21-foot (6.5 meter) Magellan Baade Telescope at the Las Campanas Observatory in Chile. With the help of detailed The Milky Way map, created by the European Space Agency‘s Gaia space telescope, the researchers observed 200 stars that were sitting in the farthest reaches of our galaxy, located towards the Magellanic Stream.
They analyzed the spectrum of light coming from these stars and found that the chemical composition of 13 materials matched the composition of the Magellanic Clouds. The measurements also indicated that those 13 stars must be between 150,000 and 400,000 light year from Worldbecause of the expected distance of the Magellanic Stream.
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The stream, first discovered in the 1970s, spans a region of the Southern Sky equivalent to the size of 300 full moons as seen from Earth. But despite its enormity, it takes some sensitive equipment to see it.
Astronomers think that the gas that makes up the stream was torn from the dwarf galaxies by the Milky Way’s gravitational pull. The new observations may reveal more about the nature of the stream and help scientists trying to understand how it interacts with our galaxy. So far, scientists say, the stream seems to fall into the Milky Way.
“With these results and more like them, we hope to gain a much better understanding of the formation of the Magellanic Stream and the Magellanic Clouds, as well as their past and future interactions with our galaxy,” Charlie Conroy , Professor of Astronomy at the Harvard-Smithsonian Center for Astrophysics (CfA), and co-author of the research, said in his statement.
Unlike the Magellanic Stream, the Magellanic Clouds were known to mankind since antiquity because they are clearly visible to the naked eye. However, astronomers still have many questions about the origin and history of these two galaxies, which appear to be colliding with the Milky Way. Mapping and modeling the Magellanic Stream will help astronomers understand its source galaxies, which are believed to be tracing its past.
“The beauty of a massive stellar stream like the Magellanic Stream is that we can do so many astrophysical investigations with it,” Vedant Chandra, a PhD student in astronomy and astrophysics at the CfA and lead author of the study, the statement said. “As our spectroscopic survey continues and we find more stars, we are excited to see what other surprises lie at the edge of the Galaxy.”
Scientists think that as hydrogen gas falls from the stream into the Milky Way, it creates the right conditions for star formation. By analyzing the data, the researchers also found that the stream is about twice as massive as they thought, which means that the Milky Way must have consumed much more gas than suggested by previous calculations.
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“The Magellanic Stream is the largest source of interstellar calories for the Milky Way – it’s our breakfast, lunch and dinner,” said Ana Bonaca, co-author of the study and former postdoctoral fellow at the CfA, staff scientist at Observatories Carnegie now. in the statement. “Based on the new, higher mass estimates for the Magellanic Stream, the Milky Way may have more mass than originally thought.”
By better constraining the mass of the stream and by gaining a better understanding of the Magellanic Clouds, astronomers will be able to better estimate the mass distribution of the entire stream, the scientists said in the statement.
“Much of that mass is in the form of dark matter – a poorly understood substance that exerts gravity,” the scientists said. “It will help to account for ordinary matter compared to measuring the mass of our galaxy in its distant hinterlands. dark dark content, limiting the possible properties of the latter.”
The study published in October i the Astrophysical Journal.
