A river of hydrogen gas flows outward from the Large and Small Magellanic Clouds, two dwarf galaxies located on the outskirts of the Milky Way. The contents of this river, called the Magellanic Stream, have puzzled astronomers for decades. But now, for the first time, a team of researchers has been able to locate stars within the stream’s gas clouds. This discovery will not only help them better understand the evolution of the river’s host galaxies, but also the distribution of matter in the Milky Way.
Astronomers from the Harvard-Smithsonian Center for Astrophysics found: stars Using the 21-foot (6.5-meter) Magellan Baade Telescope at Las Campanas Observatory in Chile. With detailed help Milky Way map created by European Space AgencyWith the Gaia space telescope, researchers focused on 200 stars located at the farthest points of our galaxy, in the direction of the Magellanic Current.
They analyzed the spectrum of light emitted from these stars and found that the chemical composition of 13 subjects matched that of the Magellanic Clouds. Measurements also suggested that these 13 stars should be between 150,000 and 400,000 stars. light years from SoilAbout the expected distance of the Magellanic Stream.
Relating to: Magellanic Clouds should be renamed, astronomers say
First discovered in the 1970s, the stream spans a region in the Southern Sky equivalent to the size of 300 full Moons seen from Earth. But despite its size, some sensitive equipment is required to see it.
Astronomers think that the gas forming the stream was torn away from dwarf galaxies by the gravitational force of the Milky Way. The new observations could reveal more about the nature of the stream and help scientists trying to understand how it interacts with our galaxy. As of now, the stream appears to be falling into the Milky Way, scientists say.
“With these and similar results, we hope to gain a much better understanding of the formation of the Magellanic Current and Magellanic Clouds, as well as their past and future interactions with our galaxy,” said Professor of Astronomy Charlie Conroy. said the Harvard-Smithsonian Center for Astrophysics (CfA) and co-author of the study. expression.
Unlike the Magellanic Stream, Magellanic Clouds known to humanity They have been clearly visible to the naked eye since ancient times. But astronomers still have many questions about the origin and history of these two galaxies that appear to be colliding with the Milky Way. Mapping and modeling the Magellanic Stream will help astronomers advance their understanding of source galaxies believed to follow their past orbits.
“The beauty of having a large stellar stream like the Maellan Stream is that we can now do a lot of astrophysical research with it,” said PhD student Vedant Chandra. astronomy in astrophysics at 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 surprises the galactic outskirts have in store for us.”
Scientists think that hydrogen gas from the stream fell into the Milky Way, creating the right conditions for star formation. By analyzing the data, the researchers found that the current was about twice as large as they thought; This means that much more gas must be swallowed by the Milky Way than previous calculations suggested.
Related Stories:
— Dark energy camera captures hyper-detailed images of nearby dwarf galaxies
— Hubble Space Telescope reveals a fascinating star cluster (photo)
— James Webb Space Telescope highlights spectacular young stars in neighboring galaxy (photo)
“The Maellan Stream is the dominant source of the Milky Way’s stellar calories; it is our breakfast, lunch and dinner,” said study co-author Ana Bonaca, a former CfA postdoctoral fellow and now a staff scientist at Carnegie Observatories. in the statement. “Based on new, higher mass estimates for the Magellanic Stream, the Milky Way may weigh more than initially thought.”
By better constraining the mass of the stream and gaining a better understanding of the Magellanic Clouds, astronomers will be able to better estimate the mass distribution of the entire Milky Way, the scientists said in the statement.
“The majority of this mass is in the form of dark matter, a poorly understood, gravitational substance,” the scientists said. “Better measuring the mass of our galaxy in its distant hinterland will help calculate matter with ordinary matter.” dark matter The contexts restrict the possible properties of the latter.”
Study published in October Astrophysical Journal.