10-24-2018, 04:24 PM
What stops stars from forming in galaxy clusters?
A long-term mystery may have been solved. It's been known for some time that normal galaxies stopped forming stars in the early universe when they fell under the gravitational influence of galaxy clusters but we've never figured out why this is the case. A new study, using the Keck and Gemini observatories on Mauna Kea, suggest the reason is due to hot gas, heated by the stars in the cluster, stripping away the cold dust and gas that's needed to fuel the star-formation process.
https://phys.org/news/2018-10-insight-ga...stars.html
"Using some of their own newly discovered SpARCS clusters, the new UCR-led study discovered that it takes a galaxy longer to stop forming stars as the universe gets older: only 1.1 billion years when the universe was young (4 billion years old), 1.3 billion years when the universe is middle-aged (6 billion years old), and 5 billion years in the present-day universe.
"Comparing observations of the quenching timescale in galaxies in clusters in the distant universe to those in the nearby universe revealed that a dynamical process such as gas stripping is a better fit to the predictions than strangulation or outflows," Foltz said."
A long-term mystery may have been solved. It's been known for some time that normal galaxies stopped forming stars in the early universe when they fell under the gravitational influence of galaxy clusters but we've never figured out why this is the case. A new study, using the Keck and Gemini observatories on Mauna Kea, suggest the reason is due to hot gas, heated by the stars in the cluster, stripping away the cold dust and gas that's needed to fuel the star-formation process.
https://phys.org/news/2018-10-insight-ga...stars.html
"Using some of their own newly discovered SpARCS clusters, the new UCR-led study discovered that it takes a galaxy longer to stop forming stars as the universe gets older: only 1.1 billion years when the universe was young (4 billion years old), 1.3 billion years when the universe is middle-aged (6 billion years old), and 5 billion years in the present-day universe.
"Comparing observations of the quenching timescale in galaxies in clusters in the distant universe to those in the nearby universe revealed that a dynamical process such as gas stripping is a better fit to the predictions than strangulation or outflows," Foltz said."