Archive | January 2009

Galaxy Zoo goes to Bristol part 2: Alice's Talk

Following Alice’s talk in Bristol, we’ve got an audio recording of it available here.

Galaxy Zoo in the News: Science Magazine

Galaxy Zoo made it into one of the lead article (subscription req’d) in Science Magazine on the International Year of Astronomy and the American Astronomical Society meeting in Long Beach (where many Zooites met up). From the article:

Because anyone can search the sky, astronomy remains the most democratic of sciences–perhaps the only one in which an amateur can still make a bona fide discovery. In August 2007, Hanny van Arkel did just that. The primary-school teacher from Heerlen, the Netherlands, spotted a strange blue blob in the sky. The intergalactic ghost turned out to be an enormous cloud of gas that is reflecting the light lingering from a now-dead quasar in a nearby galaxy to create a never-before-seen “light echo.” The discovery of Hanny’s Voorwerp (Dutch for Hanny’s Object) earned Van Arkel, 25, a moment of fame. “My name was all over the world, and that’s fun,” she says. 

At the same time, the discovery highlights dramatic changes within astronomy. Van Arkel made her find not by looking through a telescope–she doesn’t own one–but by viewing on her computer some of the millions of images of galaxies captured by the Sloan Digital Sky Survey, an 8-year-old project cataloging everything that can be seen in a vast swath of sky with a 2.5-meter telescope on Apache Point in New Mexico. Van Arkel is one of more than 160,000 volunteers helping to classify 1 million galaxies as part of an outreach program called Galaxy Zoo.

 

Science magazine is the weekly journal of the AAAS, so this is a fabulous piece of publicity for us!

Galaxy Zoo Goes to Bristol

Slightly short notice, but if you’re in or near Bristol, UK, there are two Galaxy Zoo talks taking place this Friday, 23rd January. They’re at the Bristol Astronomical Society, but anyone is welcome to attend.

One talk will be Rick Nowell, about the peas – which are becoming a remarkably large topic; more here, here and here – and one will be me be talking about Galaxy Zoo generally. It’s a “club night”, which means that several speakers will cover various topics. There will be professional and amateur astronomers in the audience, and I hope some members of the public such as you, too. We’re still debating on whether to podcast it or not . . .

The address is Bristol Grammar School, which is next to Bristol University, very near the centre. It starts at 7:15 p.m. and is free. We’ll meet in the Sixth Form Club. Rick very kindly sent me this map – Bristol Grammar School is right in the middle of it: http://www.bristol.ac.uk/university/maps/precinct.html

Very many thanks to the Bristol Astronomical Society for inviting me along, to zookeeper Bob for letting me pinch a few of his SDSS-related slides, to all of you for posting fabulous pictures and being such keen and inspiring citizen scientists for the last 18 months and thus giving me so much to talk about, and to Rick for taking a lot of trouble to arrange these talks.

Hope to see you there!

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:

Kevin and Jordan at the IYA reception 

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: