kinematics, chemical abundances

On day three of The Fabulous, Flores showed amazing IFU spectra that clearly show a cold, rotating disk and a hot bulge in ordinary, moderate redshift galaxies. He could potentially do real bulge-disk decomposition—ie, with no assumption about radial profiles of either component—although the experiment would certainly not be trivial.

Pettini and others discussed chemical abundances. One of Pettini's punchlines (old news, now) is that essentially all gravitationally bound systems with lots of stars have solar abundances, and systems found any other way (eg, by absorption) have abundances all over the hoo. Many were unsurprised; after all it doesn't take long to get to solar. But isn't it surprising that they never get above solar? (BTW, Pettini also showed that some metallicity calibrations are suspect, and many high metallicity results will come down.)

All this is related to the G-dwarf problem. Yesterday, Crampton showed that the evolution he sees in the metallicity-mass relation is consistent with the global star-formation rate density results. If so, then the Milky Way must be a strange outlier (because by Crampton's standards it would show a huge discrepancy between its stellar and metallicity-based star-formation history determinations).

[Disclosure: this post was posted two days late]

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