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Originally Posted by Andromeda321
Interesting as this conversation is, who wants to hear the next installment in Andromeda's astronomical adventures? Hmmm, that sounds like a cheesy Saturday morning cartoon series... quick, I need a theme song! :wink:
(snip)
Ok, on to the cool stuff! While I was patiently labeling a printout of the spectrum (the printers finally came back online) the person I'm working under asked me to come talk to her. She'd seen the spectrum last Friday and had an interesting bit of news to tell me about it. The zinc I mentioned a few days ago had an equivalent width greater then 2, for the record, and since I've no experience in the field I didn't know that was odd. But apparently zinc is supposed to be incredibly rare being a metal and all and apparently my quasar is the first ever observed to have a zinc line like that!
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Yes, this is much more interesting! While we're all waiting, allow me to heighten the suspense for those who don't follow high-redshift cosmic chemistry.
Many people find quasars as interesting for what the illuimnate as for their intrinsic properties. Since we can see them so far away, their light often passes through gas on the outskirts of galaxies which are too dikm for us to analyze by their own light. Here's an example of such a galaxy first seen from its redshifted 21-cm hydrogen absorption which turned up in Hubble images:
(See
http://www.astr.ua.edu/keel/agn/3c196.html for details). Using these intervening absorption lines has allowed a look at the chemistry of galaxies whether they're easy to see or not. If our galaxy is typical, we expect to see similar histories of the production of heavy elements from stars in our galaxy, from ages of old stars, and from the gas abundances in other galaxies as we go out in redshift. There are two ways one might see a strong zinc absorption line, both interesting but in rather different ways. It might mean that the quasar light goes through a very gas-rich part f the galaxy without too much being lost to dust - in which case this will be a chance to learn about additional elements that are normally too weak to measure. If it's only zinc which is enhanced among the observed elements, that's even more interesting, suggesting that something is different about this galaxy or the piece of it that we're seeing.
Zinc already stretched the amount of this metal predicted from explosions of massive stars (from a recent paper by Prochaska and company), so galaxies withg even more zinc are telling us about something we don't understand as well as we thought. And that's how science makes progress.
So - come on, Andromeda321, tell us more!