Source:
Institute for Advanced Study
Summary:
It is well known that the expansion of the universe is accelerating due to a mysterious dark energy. Within galaxies, stars also experience an acceleration, though this is due to some combination of dark matter and the stellar density. In a new study, researchers have now obtained the first direct measurement of the average acceleration taking place within our home galaxy, the Milky Way.
FULL STORY
It is well known that the expansion of the universe is accelerating due to a mysterious dark energy. Within galaxies, stars also experience an acceleration, though this is due to some combination of dark matter and the stellar density. In a new study to be published in Astrophysical Journal Letters, researchers have now obtained the first direct measurement of the average acceleration taking place within our home galaxy, the Milky Way.
Led by Sukanya Chakrabarti at the Institute for Advanced Study with collaborators from Rochester Institute of Technology, University of Rochester, and University of Wisconsin-Milwaukee, the team used pulsar data to clock the radial and vertical accelerations of stars within and outside of the galactic plane. Based on these new high-precision measurements and the known amount of visible matter in the galaxy, researchers were then able to calculate the Milky Way’s dark matter density without making the usual assumption that the galaxy is in a steady-state.
“Our analysis not only gives us the first measurement of the tiny accelerations experienced by stars in the galaxy, but also opens up the possibility of extending this work to understand the nature of dark matter, and ultimately dark energy on larger scales,” stated Chakrabarti, the paper’s lead author and a current Member and IBM Einstein Fellow at the Institute for Advanced Study.
Stars hurtle through the galaxy at
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