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hubie [soylentnews.org] writes:

A team of University of Copenhagen astrophysicists has arrived at a major result regarding star populations beyond the Milky Way [science.ku.dk]:

Since 1955, it has been assumed that the composition of stars in the universe's other galaxies is similar to that of the hundreds of billions of stars within our own – a mixture of massive, medium mass and low mass stars. But with the help of observations from 140,000 galaxies across the universe and a wide range of advanced models, the team has tested whether the same distribution of stars apparent in the Milky Way applies elsewhere. The answer is no. Stars in distant galaxies are typically more massive than those in our "local neighborhood". The finding has a major impact on what we think we know about the universe.

"The mass of stars tells us astronomers a lot. If you change mass, you also change the number of supernovae and black holes that arise out of massive stars. As such, our result means that we’ll have to revise many of the things we once presumed, because distant galaxies look quite different from our own," says Albert Sneppen, a graduate student at the Niels Bohr Institute and first author of the study.

[...] According to the researchers, the new discovery will have a wide range of implications. For example, it remains unresolved why galaxies die and stop forming new stars. The new result suggests that this might be explained by a simple trend.

"Now that we are better able to decode the mass of stars, we can see a new pattern; the least massive galaxies continue to form stars, while the more massive galaxies stop birthing new stars,. This suggests a remarkably universal trend in the death of galaxies," concludes Albert Sneppen.

For context, this is about constraining the Initial Mass Function [wikipedia.org] (IMF), which is a relationship about stellar mass distributions. This work has added a new parameter (temperature of the interstellar gas) to the IMF model and used a lot data to say that an IMF skewed to the heavier side works best, though I’m not sure this result is turning the field on its head as much as the university PR department seems to suggest.

Journal Reference:
Albert Sneppen et al 2022 ApJ 931 57 [open]. DOI: 10.3847/1538-4357/ac695e [doi.org]

Original Submission