Warning: This “History of the Peas” is rather long. At Carie’s request, Rick wrote a shorter version here.

The SDSS telescope has five colour filters, one of which is green. Like a rainbow played backwards as it splits in a prism, the colours from all filters are shown to us all at once, so we see them mixed and averaged out – usually twinkling blue star formation, golden ellipticals, and red faraway objects or nearby stars. When an object moves relative to Earth while the SDSS telescope images it, sometimes only gets through the green filter at one given time and thus leaves a pure green image in our pictures – which is usually the case with a camera glitch, one of the three images of asteroids, or satellite trails.

Some objects, though, seem to be green in their own right. We were all so busy in the first month of Galaxy Zoo trying to work out what pretty much anything was, and getting used to a hundred and one things new and strange, that not all of us (certainly not me) paid much attention to the random greenness. Those who did found a great variety of forms:

Read More…

Attention cloud hunters! With a lot of input and assistance from laihro, waveney, and ZookeeperKevin, I am pleased to announce a new specialized galaxy hunt, targeted at galaxies with active nuclei to pull out the ones with bright clouds in an organized way. At
http://wavwebs.com/GZ/voorwerpje/Hunt.cgi
you can go through SDSS images of known AGN and help us tell which ones are most likely to have the kind of gigantic ionized-gas clouds which can tell us about the history of the active nucleus and its surroundings. First you’ll see an introduction to why the problem is interesting, and offering some examples of what we’re looking for and some kinds of imposters we want to weed out. You can use existing logins from the merger and irregular classification projects if you have one – otherwise, feel free to join in. The more the merrier – or at the very least, the more, the faster and more statistically robust. And keep visiting – we’ll be augmenting the galaxy list with more AGN that are known but don’t have SDSS spectra, but it will take a little more time to get those identifications fed into the list.

Whence the web name? These clouds have a lot in common with Hanny’s Voorwerp, but are much smaller – so we go with the Dutch diminutive form “voorwerpje”. We do know of more than one, so “voorwerpjes” would also make sense.

Back in March I was speaking to a colleague of mine in Nottingham, Seb Foucaud, about the Galaxy Zoo Peas, and showing him Carie’s paper. Seb works primarily on very distant (high redshift) massive galaxies, often using data from the UKIDSS Ultra Deep Survey. He quickly noticed that the way Carie selected Peas from SDSS data was very similar to the way they select high redshift galaxies, except that the exact colours used were different, as more distant galaxies are redder.

Read More…

Sometimes in scientific research opportunities collide and lead to rather busy days. Yesterday I had such a day, and since it involved me giving two presentations about Galaxy Zoo I thought you might be interested to hear about it.

In the morning I gave a talk “Galaxy Evolution in the Galaxy Zoo”  at the “Unity of the Universe” conference in Portsmouth, a conference celebrating the opening of the new Dennis Sciama Building for the Institute of Cosmology and Gravitation (ICG, where I and several other “Zoo Keepers” work). This talk was aimed at summarizing for astronomers and cosmologists at the meeting the exciting results on galaxy evolution which have come out of Galaxy Zoo. Many researchers in astronomy are aware of Galaxy Zoo, and in general are very interested in it, but they tend to think of it more an an opportunity for outreach with the interested general public and less in terms of the exciting science which can come out of it. The point of my talk was to say that it should in fact be viewed as both. It seemed to go over well.

Over lunch I took a train to London where in the afternoon I was interviewed by an esteemed panel of scientists (including Baroness Susan Greenfield, Director of the Royal Institution, and Prof. Alec Boksenberg, Chair of the UK National Commission for UNESCO). This interview was because I was a finalist in the competition for the 2009 L’Oreal UNESCO UK/Ireland Fellowships for Women in Science. My proposal for this fellowship (for £15000) was to extend my period of study at Portsmouth so I could spend more time studying the red spirals in Galaxy Zoo (among other things). I gave a 10 minute talk about this proposed research, then answered questions from the panel.

Later that afternoon I had a L’Oreal makeover (really – but don’t worry this was not a requirement for the fellowship just a treat, and a positive sign in my opinion of a recognition that scientists can want to be feminine) and in the evening I attended a reception at the Royal Institution at which the winners of the fellowship were announced. Unfortunately I did not win the competition, but as I did make the final 8 (out of 240 applicants) I can’t feel too bad about it. I also got a nice engraved pen, met some very interesting people, and I’m assured I can still expect some free makeup. So that’s not too bad after all!

Quite a busy day in the life of an astronomer!

We are happy to announce that our paper, “Galaxy Zoo: Disentangling the Environmental Dependence of Morphology and Colour”, has been accepted for publication in the Monthly Notices of the RAS. We showed that much, but not all, of the correlation between a galaxy’s morphology and its large-scale environment can be explained by the correlation between galaxy colour and environment. We also showed that, among red galaxies, galaxies classified as ellipticals are more likely to be located in the central regions of galaxy groups and clusters. Finally, we argued that a relatively large fraction of red spiral galaxies are “satellite” galaxies in groups.

The pre-print of the accepted paper is available on astro-ph.