I posted this comment on Karen's excellent recent blog post What’s all the fuss about bars in galaxies?. As there was no reponse, I thought I'd post it here, to see if the wider community is interested (and also knows at least some answers).
Would you say a few words about ‘thick disks’ please? As I understand it, at least some spiral galaxies have them (including our own Milky Way), and as the name says, they are not thin. How does the existence of thick disks relate to rotating dark matter halos?
Also, what about the fact that a lot of bars seem to have a ‘vertical’ component, as evidenced by the large number of X-shaped/peanut-shaped/boxy edge-on spirals? Is this vertical extension also found in simulations?
Finally, as far as I know, lenticulars – disk galaxies with no obvious arms – can have quite flat disks, but they seem to lack bars; why?
by
JeanTate