Today’s guest blogger is Raul Jimenez who collaborated with us on an exciting paper on the spin (clockwise vs. counter-clockwise) of spiral galaxies.

The rate at which galaxies transform gas into stars as a function of time gives astronomers insight into the way galaxies formed and evolved. By using the SDSS spectra  one can infer the past star formation history of a galaxy. We have been doing this using sophisticated statistical tools, take a look here. Much has been learned about the formation of galaxies using their star formation history, for example we know that the most massive  galaxies assemble their stars early on, about 1-2 Gyr after the big-bang while small  mass galaxies (100 to 1000 times smaller than the milky way) do it during the whole age of the universe. What we have done in our recent paper is to look at how the star formation history of galaxies correlates to  the rotation direction of galaxies as measured by the galaxy zoo project. What we have found is that  galaxies that had lots of star formation in the past do tend to rotate in the same direction in groups with lengths of about 10 to 20 Mpc.

Although this might sound surprising, it is not! If one reviews very old papers, almost 40-50 years ago, where people like Andrei Doroskievich worked out the way galaxies should rotate based on how they were formed in the past, one realizes that the correlation we have found arises naturally in these models of galaxy formation, so-called hierarchical models. What is happening is that in the past the cluster of galaxies was not yet formed and the spiral galaxies that the galaxy zoo has been classifying by morphology were  coming down the filamentary structure into the proto-clusters. Because the proto-cluster already contains the big elliptical galaxies, they  provide the same  “pull” on all the spiral galaxies in the filament.  So it is quite exciting to see this result from the galaxy zoo and the MOPED/VESPA catalogs. Now it is time to go back to theory and  numerical simulations and understand better what it means for galaxy formation and evolution. This is something we will do next.

The paper has been submitted to MNRAS, and the pre-print is available for download on astro-ph.

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We’ve had a busy afternoon here at the Zoo working hard to merge the Galaxy Zoo and Galaxy Zoo forum user accounts.  I’m pleased to say that the process is now complete!

The details of the merge process have been outlined in this earlier post but basically some of you will have had your accounts merged automagically, others of you will have to ‘reclaim’ your old Zoo or forum account by using our merge tool.  If you are having trouble logging in since the merge then please use the password reset form at this address:  https://galaxyzoo.org/signup

Unfortunately as a consequence of moving the forums to a new server some people won’t be able to see the forums for up to 24 hours.  Don’t worry though, they are there and you’ll be able to see them soon!  (It’s a DNS propagation issue for you tech-minded folk out there.)

Merging the different accounts has been a long-term goal for us at Galaxy Zoo and we’re really pleased to finally have the right solution in place.  It’s been a real programming challenge to get the logic just right and it wouldn’t have been possible without a huge amount of effort from Scott Miller and Pamela Gay and the rest of her team at SIUE - thanks guys!

We realise that the merge may cause problems for a few of you so if you have any questions or are having trouble logging in then please email us at team@galaxyzoo.org

Cheers

Arfon

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You may have noticed that the forums are again in maintenance mode and new registrations are disabled on the Zoo at the moment. That’s because we’re currently churning away in the background merging the accounts from both databases. For more information have a read of our earlier post We should have some more news for you later today…

Cheers
Arfon

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So it’s been a busy 24 hours at Galaxy Zoo.  As we outlined in the earlier posts were working hard on unifying the Galaxy Zoo and Galaxy Zoo forum accounts. During the merge we had to disable the forums and new registrations on the Zoo so that we could be sure of exactly who was registered where.

So 24 hours later and with some tired eyes I’m sorry to report that we ran into a few technical difficulties with the merge. Specifically, the tests we had in place for checking the post-merge user accounts showed us that we had some problems. It’s of prime importance to us that we get this right and once we’d done the merge we weren’t completely satisfied that things were exactly as they should be.

So what next?

We’ll by now you should see that the forums are back up again as are new registrations on the Zoo and so we’re back to how things have always been. We’re going to review what happened yesterday, figure out what went wrong and then have a go again in the next week or so. Watch this space!

Cheers
Arfon & The Team

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So the long promised forums/Zoo accounts merge is underway but unfortunately things are moving a little slower than we’d like.  The good new is we’re making good progress, the bad news is the forums won’t be back up until tomorrow now - sorry!

More news in the morning…

Cheers

Arfon

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