Far out cosmology: differing star nurseries (Introduction)

by David Turell , Tuesday, June 08, 2021, 18:42 (1051 days ago) @ David Turell

Galaxies have mixed ways of making new stars:

https://phys.org/news/2021-06-cosmic-cartographers-nearby-universe-revealing.html

"A team of astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) has completed the first census of molecular clouds in the nearby universe, revealing that contrary to previous scientific opinion, these stellar nurseries do not all look and act the same. In fact, they're as diverse as the people, homes, neighborhoods and regions that make up our own world.

"Stars are formed out of clouds of dust and gas called molecular clouds, or stellar nurseries. Each stellar nursery in the universe can form thousands or even tens of thousands of new stars during its lifetime. Between 2013 and 2019, astronomers on the PHANGS project (Physics at High Angular Resolution in Nearby GalaxieS) conducted the first systematic survey of 100,000 stellar nurseries across 90 galaxies in the nearby universe to get a better understanding of how they connect back to their parent galaxies.

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"To better understand star formation in different types of galaxies, the team observed similarities and differences in the molecular gas properties and star formation processes of galaxy disks, stellar bars, spiral arms, and galaxy centers. They confirmed that the location, or neighborhood, plays a critical role in star formation.

"'By mapping different types of galaxies and the diverse range of environments that exist within galaxies, we are tracing the whole range of conditions under which star-forming clouds of gas live in the present-day universe. This allows us to measure the impact that many variables have on the way star formation happens," said Guillermo Blanc, an astronomer at the Carnegie Institution for Science, and a co-author on the paper.

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"Annie Hughes, an astronomer at L'Institut de Recherche en Astrophysique et Planétologie (IRAP), added that this is the first time scientists have a snapshot of what star-forming clouds are really like across such a broad range of different galaxies. "We found that the properties of star-forming clouds depend on where they are located: clouds in the dense central regions of galaxies tend to be more massive, denser, and more turbulent than clouds that reside in the quiet outskirts of a galaxy. The lifecycle of clouds also depends on their environment. How fast a cloud forms stars and the process that ultimately destroys the cloud both seem to depend on where the cloud lives.'"

Comment: this will only add to dhw's confusion as to why God created this universe, which is not uniform everywhere. We still don't have many answers about the mysteries we observe. The simplest approach is to accept God's doings and then figure out why.