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adamginsburg t1_je1v4o8 wrote

Just a quick two cents here: supernovae, yes, but not quasars. Quasars are accreting black holes, and while there might be some production of heavy elements in their accretion disks, those elements likely do not get returned to the surrounding galaxy to form new stars. Besides supernovae, neutron star mergers (which another poster already noted) may also produce significant heavy elements, and AGB stars also produce some of the moderately-heavy elements - but with quite a different distribution. Cartoons like this one give a good summary of which routes are responsible for making each.


AuDHDiego t1_je1w58v wrote

This is really helpful thank you! So there's not much significant matter expelled from accretion disks?


adamginsburg t1_je1wwcd wrote

There actually is a decent amount expelled in gigantic jets, but the jets from quasars are relativistic (i.e., travel at a significant fraction of the speed of light) and escape the galaxy. Google "radio galaxies" and look at those images: they show jets shooting to megaparsec size scales (i.e., 10-100x bigger than galaxies), so that material totally escapes the galaxy.

That said, there is probably some material from quasars that gets mixed back into the galaxy - I think not that much, but honestly there's a lot unknown about gas cycling in the vicinity of rapidly accreting black holes. Nevertheless, even if all the accretion disk material got fed back into the galaxy, it would represent a truly tiny fraction of the galaxy's mass, much less than the material made by supernovae (our black hole is 10^6 solar masses, our galaxy is ~10^12 solar masses, of which ~10^11 is baryonic - so the black hole is a tiny fraction of the galaxy, and the accretion disk is a tiny fraction of that. my numbers here are super rough)


AuDHDiego t1_je22f3r wrote

Oh just saw that you're the author of the referenced paper! Gosh oops that I missed that!


Congratulations on finding the salty disk!