Scientists Believe the Shape of the Dark Matter Halo is Key to Decoding the Hierarchical Formation of the Milky Way Galaxy.
Despite extensive efforts in recent decades, the shape of this dark matter halo remains a contentious issue.
The current dark matter halo of the Milky Way has a somewhat flattened shape. (Source: Phys).
In a recent study published in the journal Nature Astronomy, Chinese scientists suggest that the current dark matter halo of the Milky Way is “somewhat flattened.”
Based on observational data from the Gaia satellite of the European Space Agency and the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) in China, researchers from the University of Chinese Academy of Sciences (UCAS), in collaboration with several national and international research organizations, analyzed approximately 2,600 Cepheid variable stars of various ages.
They employed a new method called “motion imaging” to construct a three-dimensional structure of the Milky Way’s disk at different ages over a span of 250 million years.
In the universe, nearly one-third of disk-shaped galaxies do not have the perfectly round shape of a classic disk but are warped like a potato chip. Astronomers refer to this phenomenon as the warping of the disk.
The Milky Way, as a typical disk galaxy, also exhibits this warping characteristic.
By observing how the warping of the disk evolves with age, researchers discovered that this warping progresses at a rate of 0.12 degrees per million years.
Associate Professor Huang Yang from UCAS, a member of the research team, noted that previously, scientists “lacked accurate measurements of how the disk shape oscillates.”
Based on new measurements, the research team found that the current dark matter halo surrounding the vertical filament takes on a slightly flattened elliptical shape.
According to Huang Yang, “these measurements provide an important anchor for studying the evolution of the Milky Way’s dark matter halo and the galaxy’s formation history.”
