I discussed galaxy morphologies and evolution in their distribution with redshift with Kartik Sheth (Spitzer). Sheth finds that the bar fraction is indeed evolving with redshift, and thinks it has to do with the mean dynamical state of disk galaxies being hotter at earlier times. I told him that I don't believe in morphology! We also discussed tests of the hypothesis that spiral arms are transients, as I mentioned in some recent post.
Jessica Krick (Spitzer) told me about intracluster stars and cD galaxies. She finds that it is very hard to decide what is a cD and what is intracluster; there may be no real distinction between these at all. She also finds it hard to measure radial gradients in their colors, because the intracluster light is so low in intensity (and she has the best flat-fielded data ever, basically). We discussed galaxy evolution and hierarchical clustering, and we figured out a possible project (based on Masjedi's projects) to see if cD galaxies are plausibly built from galaxies that fall into the clusters (the standard paradigm).
Lin Yan (Spitzer) gave a nice talk on high-redshift sources observed with Spitzer.
Hi David!
ReplyDeleteback to the bloging world! Now with some "will" to do real science posts and comments, after a series of personal problems :-).
So, I'm catching up with your block (still in may last year), and I saw that post about Krick's intracluster light work.
I quickly read the first paper, the one about A3888 and now with the second one is astro-ph, both were in the "to be read urgently" list. Don't remember the technique they use to the detection. But surely flatfielding is a major issue and it's very low intensity to a good gradient measurement.
The cD x ICL is am important question, some previous work tried to put some light in it (Gonzales and Feldmeier, among others).
Anyway, my concearn on ICL/IGL is always about the technique. But we're having problems to measure "local" properties in the compact groups also, like color patches or gradients, even though the overall properties are reliable. It's being submitted next month.
It's good to be back on reading your blog! I'll be up to date in a week or so!