In a new study, a team of astronomers has used Nasa's Hubble Space Telescope to shed new light on the mysterious nature of dark matter, the invisible substance that makes up most of the universe's mass.
Dark matter is a type of matter hypothesised to make up about 27% of the universe's mass and energy.
Unlike ordinary matter, dark matter does not emit, absorb, or reflect light, making it invisible and detectable only through its gravitational effects on visible matter, radiation, and the large-scale structure of the universe.
This study not only advances our understanding of dark matter distribution but also demonstrates the value of long-term astronomical observations.
The methodologies developed for this research can be applied to other galaxies, potentially revolutionising our comprehension of dark matter across the universe.
In a new study, a team of astronomers has used Nasa's Hubble Space Telescope to shed new light on the mysterious nature of dark matter, the invisible substance that makes up most of the universe's mass.
Dark matter is a type of matter hypothesised to make up about 27% of the universe's mass and energy. Unlike ordinary matter, dark matter does not emit, absorb, or reflect light, making it invisible and detectable only through its gravitational effects on visible matter, radiation, and the large-scale structure of the universe.
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The research, focused on the Draco dwarf galaxy located about 2,50,000 light-years from Earth, has provided the most accurate three-dimensional understanding of stellar movements within this diminutive galaxy to date.
The study, which spanned 18 years of Hubble observations, aimed to resolve a longstanding debate in astrophysics.
While computer simulations suggest that dark matter should concentrate in a galaxy's center, forming a "density cusp," previous observations have indicated a more even distribution throughout galaxies. A team of astronomers analyzed observations by Nasa's Hubble Space Telescope taken over a span of 18 years to measure the dynamic motions of stars within the Draco dwarf galaxy. (Photo: Nasa)
Led by Eduardo Vitral of the Space Telescope Science Institute (STScI), the team analyzed the positions and movements of stars in the Draco dwarf galaxy with unprecedented precision.
By combining line-of-sight velocity measurements with proper motion data, they created a comprehensive 3D model of stellar movements.
"Our models tend to agree more with a cusp-like structure, which aligns with cosmological models," Vitral explained. This finding could have significant implications for our understanding of dark matter's behavior and its role in galactic evolution.
The research benefited from Hubble's long-term observations, allowing for extremely precise measurements of stellar motions.
According to co-author Sangmo Tony Sohn, the precision achieved is equivalent to measuring the annual shift of a golf ball on the Moon as seen from Earth.
This study not only advances our understanding of dark matter distribution but also demonstrates the value of long-term astronomical observations. The methodologies developed for this research can be applied to other galaxies, potentially revolutionising our comprehension of dark matter across the universe.
Published By: Sibu Kumar Tripathi Published On: Jul 15, 2024
