Do Bars Kill Spiral Galaxies?
This morning a press release went out from the Royal Astronomical Society about the Galaxy Zoo 2 paper I have previously blogged about (post about submission, arXiV link, post about acceptance).This paper on the trends of the fraction of disk galaxies which have bars is currently in press at Monthly Notices.
If you recall, our main finding was that redder disk galaxies are significantly more likely to host a bar than bluer disk galaxies, with the red spirals being the extreme of that population (very red disk galaxies, almost all of which seem to host bars).
So we speculate that the bar might somehow be involved with the process which turns the disk galaxies red – and the press release has gone our with the title “Bars Kill Spiral Galaxies”.
Of course it might not be quite that simple – it’s possible that the increased likelihood of having a bar is actually a side effect of the disk being red, or even that both phenomena (the disk turning red, and getting bar) are coming from some third process to do with the environment the galaxies live in. My best guess is that it’s some combination of all those factors working together – but of course we don’t do science on “best guesses” so lots more work is happening using the sample of bar classifications you gave us in Galaxy Zoo 2. We’re studying the fraction as a function of local environment, I’ve already mentioned here the results which came from the Bar Drawing site which are very exciting (more on that soon), and I’m also working on combining your classifications with information on the gas content (the fuel for future star formation) from the ALFALFA survey (which uses Arecibo – a very cool telescope).
I think what’s very interesting is all this could have an impact on the future fate of our own Galaxy which is known to host a bar.
So that’s lots of exciting science coming soon, and thanks again for all those clicks!