Calling A Level students : Want to be a Zookeeper?
This post is only relevant to UK students taking their ‘A’ levels – sorry everyone else
When I was 17, I spent a summer working with Stuart Clark. Stuart’s now a full-time writer, but at the time he was still a researcher at the University of Hertfordshire. The ‘work’ I got done that summer – playing around with models of dust around newly forming stars – didn’t make any meaningful contribution to science, but I came away having learnt a huge amount, both about astronomy and about life as a an academic.
Do you fancy working with the Galaxy Zoo team this summer? We’d like to apply for two Nuffield bursaries, the scheme which made my trip to Hertfordshire possible, for sixth form students to work with us in Oxford or Portsmouth. Between us we’ll choose a project involving Galaxy Zoo data and apply to Nuffield for funding to support your work. The money isn’t a lot, but it’s more than you’d earn from a terrible summer job and it’s a good chance to polish your cv before university applications come round.
If you’re interested, drop me an email on chrislintott AT cantab.net with the subject line ‘Nuffield bursary’. Tell me why we should choose you, what ‘A’ Levels you’re doing at which school, and whether you’d be willing to work in Oxford, Portsmouth or both. Time is short, so make sure your emails arrive before noon next Monday, the 26th. We look forward to working with you.
eGZeLENS update: HST pre-imaging
Hello there!
My name is Phil Marshall, and I’m a postdoctoral research fellow in astrophysics at the University of California, Santa Barbara. My main research interests are in finding new strong gravitational lenses, and then using them to make accurate measurements of galaxy masses. I am involved with several semi-automated lens searches, using data from the Hubble Space Telescope (the HAGGLeS project) and also the CFHT legacy survey (the SL2S project). Several years ago some colleagues and I were joking about how one could find lenses at a hypothetical classification website called “www.lensornot.com” – imagine how excited I was to find you all doing this already in the galaxy zoo!
I got talking to Chris about the galaxy zoo project when I visited Oxford this last summer – I met Aprajita then as well, and we looked through the candidates you had generated while classifying galaxy morphology. It was encouraging to see some of the Fermilab and Cambridge groups’ lens candidates pop up (you know, the 8 O’Clock Arc, the CASSOWARY sample and so on), but even more exciting to see some new candidates! As you read in our previous post, Aprajita and I made a shortlist for the Gemini run together, trying to pick the systems most likely to be lenses. This is tricky, as the SDSS resolution is quite poor: lenses tend to be far away, and therefore small and not well-resolved in the SDSS images. We focused on the objects that looked like wide separation lensed quasars – these are predicted to be quite rare, but there should still be a handful in the whole 8000 square degrees of the SDSS survey.
Now, spectroscopy is expensive (as the exposure times have to be quite long), so it’s common to try and reduce the risk of observing lens candidates by taking cheaper observations in advance to prevent disappointment later. These might be high resolution imaging, to test in more detail the lens image geometry hypothesis, or short exposures with a spectrograph to see if the objects in the field are at a different redshift (distance) than the lens
galaxy. On September 24th, an opportunity presented itself, as we in the SL2S collaboration received an email from our HST observations coordinator. With the demise of the NICMOS instrument, there was only one working camera onboard HST: the optical imager, WFPC2. As you can imagine, with 100% of the observing time being given to WFPC2, the HST schedulers began to run out of targets! They also needed extra targets to keep HST busy in between the end of the current cycle (16) and the beginning of the next one. Here’s what the email said:
“With the recent suspension of NICMOS observations until the next
cycle it has become apparent that the HST observing efficiently may
drop if the shuttle launch slips by more than a few days and the
pool of observable targets is not augmented.STScI created the SNAPSHOT proposal category in order to counteract
any scheduling inefficiency. Consequently, the Institute is actively
scheduling all cycle 16 SNAPSHOT observations that utilize the
currently available instruments. A number of SNAPSHOT targets in
your program cannot be scheduled because their location makes them
inaccessible to HST in October.It is the nature of SNAPSHOT proposals that their targets are often
interchangeable. We are contacting you since your proposal has been
identified as having a number of yet unexecuted observations which
cannot be observed prior to the Servicing Mission.We would like to provide you the opportunity to replace these
targets with scientifically equivalent substitutes whose coordinates
are within range.”
My French SL2S collaborators and I then spent an afternoon scrambling together a list of new targets – mostly more of our own targets, but I suggested the galaxy zoo lens candidates and they agreed that, yes, these were “scientifically equivalent” and hence a good use of our telescope time. Three out of the five targets on the eGZeLENS shortlist lay within the area of sky accessible to HST in October, and these three were duly observed! Here they are – with the galaxy zoo discovery images in the top panels, and the higher resolution HST/WFPC2 images below.
Bad news folks! None of the three systems, despite looking like fairly convincing gravitational lenses in the SDSS images, are actually lenses.
SDSSJ0926-0037 (right) made every lensing aficionado I showed it to very excited – but it’s just a very compact (and symmetrical) group of galaxies. I say “just” – there can’t be many groups out there as neat as this! The other two have nice symmetrical double point-image configurations – except that in SDSSJ0813+1552 (middle) one of the “images” is a spiral galaxy. It’s not definite that SDSSJ0811+0240 (left) is not a lens – but the oval of diffuse emission around the bulge of the galaxy is not consistent with being an Einstein ring of a quasar host (it doesn’t match up with the point source positions, and is not circular enough) and is almost certainly a set of spiral arms associated with the bright yellow bulge. This would make the galaxy much less massive than it would need to be to generate the observed 6 arcsec of “image” separation: the point sources are probably stars that happen to lie (in projection) either side of a bulge-dominated galaxy!
On the bright side then, as well as avoiding wasting any hard-won Gemini time, we have learnt the following key fact about lens finding from this exercise:
The galaxy zoo is so big that it contains a significant number of objects that are very good at mimicking gravitational lenses.
We must be on our guard in future!
Kevin and Jordan at AAS
Here is another photo from the AAS meeting last week. Georgia Bracey took this photo, catching Kevin and I in the act of working during the reception before the opening of the International Year of Astronomy:
What can I say? I was curious about the peas, and Kevin had some results to show me.
After this photo was taken, Kevin shut down the laptop and we went back to drinking our free Sierra Nevada Galileo Ale. The opening of the International Year of Astronomy was great, featuring a live stream from the Cincinatti Observatory (through UStream – the video loads slowly, but it’s worth it), the premiere of a documentary called 400 Years of the Telescope, and the opening of the International Year of Astronomy island in Second Life. 2009 promises to be an exciting year in astronomy!
Galaxy Zoo meetup in New York, February 7th
Kevin and I have been talking for a while about getting a Galaxy Zoo meetup on the U.S. East Coast. While we were at AAS, we had a chance to compare schedules, and we are both free on Saturday, February 7th. We’re planning a meetup that day in New York, which is about halfway between Kevin in New Haven and me in Baltimore. Details are still being worked out – updates will be posted in the Zoo York meetup topic in the forum. Please let us know if you’ll be able to come. Post a reply here or head over to the Zoo York meetup topic in the Galaxy Zoo forum. Hope to see you there!
Galaxy Zoo amongst "Top 10 Scientific Endeavours of 2008"
Universe Today recently announced their Top 10 Scientific Endeavours of 2008, as voted for by their readers.
The Galaxy Zoo team were very pleased to find that Galaxy Zoo, and more specifically the discovery of Hanny’s Voorwerp, came in at number 8. This puts us in such fine company as exoplanet imaging, the Phoenix Mars Lander and the Large Hadron Collider!
Universe Today’s previous story on the Voorwerp is available here.
An introduction
Hello. I’m new around here and I thought I should introduce myself. My name is Arfon Smith and I’m the latest addition to the Galaxy Zoo team. I’ve been appointed to the role of technical lead and I’m looking forward to working with Chris in Oxford on some really exciting new stuff for future versions of Galaxy Zoo.
Galaxy Zoo is a great project and a perfect fit for my two main interests, Astronomy and Software. I have a PhD in Astrochemistry from The University of Nottingham where I studied the role that dust has to play in a variety of astrophysical environments.
More recently I have been working as a software developer at The Wellcome Trust Sanger Institute (Human Genome Project) near Cambridge. At Sanger, I’ve been working on web applications to support the high-throughput sequencing of DNA. It’s been a great experience but I’m really looking forward to being back in the astronomical community.
Anyway, that’s about all for now! For those of you interested, I’ll be blogging about some more technical aspects of the software development process going on behind the scenes at Galaxy Zoo. Look out for updates soon!
As promised – photos!
Chris giving his talk while wearing a pink shirt:
Kevin with his opening slide, which generated some applause from the audience:
Chris and Kevin take joint questions after both talks:
More from Chris's talk – red spirals
Chris told me in the pub yesterday that “it’s nice to give a Galaxy Zoo talk where people are already familiar with the story; it means that people already know the story.” That’s a testament to the success of your classifications — from what I’ve seen at this meeting, it seems that in just a year and a half, Galaxy Zoo has gone through evolved from a cool new strategy for doing science to a source of exciting research results. The results Chris presented about red spirals were particularly interesting. Karen Masters has blogged about these red spirals before. Spiral galaxies usually contain lots of young, blue stars, but these “red spirals” contain old, red stars. What this means is that the formation of new stars in these galaxies has been shut off. Galaxy Zoo’s contribution — your contribution — has been to show that red spirals most often live at the edge of galaxy clusters. They are clusters that have just begun to move toward the centers of clusters due to the clusters’ gravitational attraction. The attraction of the galaxy clusters has led to new star formation being shut off, but not to the shape of the galaxy changing — a process that Chris called “gentle strangulation.” The gravitational attraction is just right — enough to shut off star formation, but not enough to deform the galaxy.
A zoo-tiful morning
Day 2 of the AAS meeting is here. The Zoo team talks were yesterday. The scheduling has been a bit odd at this meeting – Chris and Kevin’s talk was in a session about galaxies, while at the same time Bob was chairing a session on cosmology with the Sloan Digital Sky Survey in which Daniel was speaking. I was able to see all the talks by staying for Chris’s and Kevin’s, then switching rooms in time to see Daniel’s. I took photos of Chris and Kevin giving their talks – photos are coming soon, after I go back to the hotel to retrieve my camera’s transfer cable.Chris went first. He started by reviewing the Zoo in general, then reviewed some of the results from the red spirals and mergers projects. Chris has graciously agreed to make his slides available on the blog, but I am having trouble getting the blog to upload the PDF file. I’ll see if I can get someone to help me with it. Meanwhile, here is the first slide to tantalize you:
Kevin went next, talking about the blue ellipticals that he has written about on this blog in the past. The biggest hit of his talk, though, was his title slide, which was written in galaxies! The slide was made by Pat from the Galaxy Zoo forum. I have a photo of it that I will post later on.
When I get a few spare minutes, I’ll post some more about these talks, and about the Sloan cosmology session.
Liveblogging – AAS meeting
Greetings from Long Beach, California! I’m here along with Chris, Kevin, Bob, and Daniel Thomas at the twice-annual meeting of the American Astronomical Society.As we’ve done at previous meetings, I’ll be liveblogging events at the meeting. Between now and Thursday, I’ll be posting in real time about what I see and do at this meeting. Some of the other zookeepers will probably blog also.I’m part of a larger team of bloggers that is covering the meeting. You can follow the coverage at the Astronomy Cast Live blog.First up, at 10 AM Pacific time (7 PM GMT) is Chris and Kevin both talking about Galaxy Zoo results. See you then!
Galaxy Zoo 