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Welcome to #GZoo10 : Day 1

It’s the day before Galaxy Zoo’s tenth birthday, and the team have gathered in Oxford for three days of discussing science and our plans for the future. Because it’s Galaxy Zoo, we’re inviting any of you who are interested to follow along online.

Members of the Galaxy Zoo team relax before the start of their meeting in an Oxford pub.

The mornings will be taken up with talks from team members. Today’s schedule is :

10am : Chris Lintott (Oxford)
10.20am: Lee Kelvin (Liverpool John Moores)
11am: Steven Bamford (Nottingham)
11.20am: Lucy Newnham (Portsmouth)
11.40am: Sandor Kruk (Oxford)
12 noon: Bill Keel (Alabama)

All the talks will be available via Oxford’ LiveStream account here. You can ask us questions using the #GZoo10 hashtag on Twitter – we will make sure someone in the audience at each session is watching so comments online make it into the room.

The afternoon will be an unconference and hack session, with the team debating the issues raised during the day and getting to work together. These sessions won’t be streamed, but we will blog about what’s going on.

It’s Becky Smethurst blogging from here on in folks… 

So we’ve kicked off the day with our fearless leader of the Zooniverse, Chris Lintott, reminding us that on this day 10 years ago the team were having conversations about how it would be amazing if they could get 10,000 people to help classify. Chris is still amazed that we’re here 10 years later with over 400,000 of you.

Chris is running through some of the modes in which we work with the Galaxy Zoo data. The first is looking at traditional morphologies, which the project was designed to do, like bars and spirals. The second is “distraction mode” where we’re all distracted by the serendipitous discoveries that the users make which we weren’t expecting, like the Voørwerpjes and the green peas. The final mode is the modelling mode, where we’re fitting models to the Galaxy Zoo data to explain something about the Universe. This mode also includes the amazing work with classifications of simulated galaxy images that are ongoing on the Galaxy Zoo site right now!

One of the questions from the audience for Chris is: “Why have the serendipitous discoveries dried up on Galaxy Zoo?” For one thing Chris thinks that one issue is that is takes so long to follow up on these discoveries – we’re still working on the Voørwerpjes! – but one thing we don’t have with the current images on the site (GAMA and KiDS etc.) is a link to the science survey site where the images come from. We had that with the original Sloan Digital Sky Survey (SDSS) images in Galaxy Zoo 1 & 2 which allowed the users to explore the data themselves and flag up something interesting.

Up next is one of the newest members to the Galaxy Zoo team: Lee Kelvin! He’s telling us about his work with the Galaxy Zoo classifications of the GAMA and KiDS survey images which have just been classified by users on the site. The special thing about GAMA is that it’s multi-wavelength; it takes images in various bands across the spectrum, from the ultra-violet to the infra-red. This is important because, as Lee points out, the morphology of a galaxy changes a lot across different wavelengths.


GAMA also has cross-over with the KiDS survey (the main role for which is to map the locations of gravitational lenses in the Universe, like those users hunted for in Space Warps!) which has much higher resolution than the SDSS images originally in GZ1 & GZ2. This means they’re perfect for classifying morphologies because more detailed features are resolved. These images are on the site right now – which means lots of pretty pictures for us to classify! These classifications give the team a wealth of information on the galaxies in these surveys – especially when users flag the interesting cases on Talk.

The early results from these classifications with the images from KiDS look very promising but Lee says there’s lots more work to be done! Including setting up a follow-up Zooniverse project trying to distinguish between true smooth elliptical shaped galaxies and disk galaxies that look smooth – so look out for that project going live in the next couple of months!

We’re back and caffeinated after a refreshing coffee break! Now Steven Bamford has taken the stand and is talking to us about the next steps for morphology studies with Galaxy Zoo.

He starts us off by reminding us that we can’t just split galaxies into spiral and elliptical galaxies anymore – it’s a lot more complicated than that with a whole evolutionary sequence of smooth disk galaxies between the pure elliptical and pure spiral galaxy sequences. It’s therefore really important to get both visual classifications from Galaxy Zoo but also quantitative morphologies. A quantitative approach is where you analyse an image to reduce the description of a galaxy down to a number – for example, how disturbed or asymmetric a galaxy is. Steven is explaining how you can do this by making a model of a galaxy’s light and subtracting off the original image and analysing what you’re left with. The problem is that the models are tidy but the galaxies are messy! Deciding which model to use is very difficult but that’s where the Galaxy Zoo classifications come in – they can be used as prior information to decide which model to use.

Steven explains the reason why we actually want to do all this model fitting is because we care about population statistics. Sometimes we don’t care about individual objects and we want to look at the big picture – to do that we need to reduce all that information down as much as we can.

Next up is one of the newest additions to the Galaxy Zoo team, Lucy Newnham a PhD Student at Portsmouth! She’s giving us a nice introduction to the big picture of galaxy evolution and how galaxies stop star forming as they evolve. She’s particularly focussing on barred galaxies and whether the bar can cause this shut down of star formation.

She’s done some follow up observations of some barred galaxies picked out by Galaxy Zoo using radio telescopes! Ionised hydrogen gas emits a very specific wavelength of light in the radio part of the spectrum (21cm) – so if you can detect emission with radio telescopes at these wavelengths it means there is hydrogen gas there to fuel star formation. It took 115 hours total observing time with the VLA and GMRT to get data for just 7 galaxies! The first one she’s reduced the data for is UGC9362 and she’s found that there is a hole in the gas in the centre of the galaxy where the bar is. She thinks that means that since the bar is rotating with the galaxy, it has carved out a hole in the gas as it does so and used up all the gas needed for star formation.

The next question Lucy is trying to answer is if the strength of the spiral arms is affecting the star formation in a galaxy? To quantify the strength of the spiral arms, Lucy is using the Galaxy Zoo classifications – where more people agree that a galaxy has spiral arms the stronger the spiral arms will be! Lucy has now looked at trends in galaxy properties with the strength of the spiral arms showing us a plot that she even made this morning! LIVE SCIENCE EVERYBODY!

Taking the stand now is another PhD student, Sandor Kruk, who will be continuing this barred galaxy theme: “Dealing with bars… and other mess”. He clarifies that when he refers to “mess” he means other morphological features!

Again, he’s focussing on this problem of what makes galaxies stop forming stars. Earlier results from Galaxy Zoo that Karen Masters worked on back in 2012 suggested that bars were a likely culprit. Sandor is now following up on this work to split the galaxy light into the separate components: bar, disk and bulge. Looking at the colour of this light will let us know if that part is star forming: red things are old, with little star formation and blue things are young, with recent star formation. To split this light he had to model the light of over 3500 galaxies! That’s a mammoth effort, but it’s paid off because he’s found that there is a difference between the colours of disks in galaxies with and without bars!

Whilst doing all this modelling, along the way he also made a serendipitous discovery: that some of the bars were offset from the centre of the disks. This is weird – it means that perhaps these galaxies have had an interaction with another galaxy which has shifted everything around. Turns out though that some of these objects had already been flagged in talk by the users! Makes us wonder what else is hiding in there that the team hasn’t yet seen!

Well Sandor reckons we should start with some of the questions of the Galaxy Zoo decision tree that the team haven’t yet had chance to look at. For example, what shape is the bulge of the galaxy – boxy or round? Does the galaxy have a ring? While Sandor has been fitting all of his 3500 galaxies (some barred and some unbarred as a control sample) for his bar study, he’s been getting some ideas for how we can tackle these questions – so watch this space!

So next up is one of the original science team members, Bill Keel! He’s sort of become the curator of the objects in Galaxy Zoo which don’t fit into any of the classifications we ask about on the site. He’ll be telling us specifically about the Voørwerpjes (i.e. ionization echos). The first one was flagged on August 13th 2007 (another 10 year anniversary coming up, mark it in your calendars!) by one of the volunteers who brought an unusual blue smudge below a galaxy to the team’s attention. Bill is now telling us how they figured out that the weird blue smudge near the galaxy turned out to be a gas cloud which had been ionised by emission from the active supermassive black hole in the centre of the nearby galaxy. We can tell this by looking at the spectrum of these objects – where we split the light into its component wavelengths to spot specific elements and molecules.

After identifying what this first object was, the users then found more! Bill ended up doing follow up observations on 20 of these objects – including 8 followed up with the Hubble Space Telescope. Turns out NGC7252, a galaxy that astronomers have been studying for 30 years, even has one of these ionised clouds!

The search continues for more of these objects – including another one flagged by a user in February 2017 in the current data being classified on Galaxy Zoo. So keep a weather eye out people!

We’re now going to open up the conference to discussion – between the team that are here and you following along online! If you’d like to ask a question or make a comment for discussion – either post it here on the blog or on Twitter with #GZoo10.

The discussion so far has covered how we consider more detailed features of a galaxy and how galaxy simulations will tie in with what we do in the future. We’re also starting the discussion of how the Galaxy Zoo site will be restructured in the future as we move to the new Zooniverse web platform – exciting!

Now we’re all off to lunch to fuel ourselves for a long afternoon of discussion and unconferencing! See you all in an hour – until then, keep tweeting!

We are back! After an afternoon of “un-conferencing” where we all suggest sessions for discussion and schedule them on the fly.

We first talked about what science we’re going to do with your classifications on the infrared images from the UKIDSS sample. We want to compare how the shape of galaxies changes from the optical to the infrared but it gets difficult because galaxies tend to be fainter and smaller in the infrared. A lot of us are keen to study how the number of bars changes from optical wavelengths to infrared wavelengths. There are some studies showing that bars disappear in the infrared, but there are also some that show that bars appear in the infrared where there are none in the optical. One of the Galaxy Zoo PhD students, Mel Galloway, has already had a quick look at this and we discussed where to take this work next! First thing first though – releasing the classifications as a data table to the public.

Our next discussion session was about the future of the Galaxy Zoo classification cite. How are we going to ask the users to classify the galaxies? The current mode is the classification tree that we get users to walk through and answer each question for every galaxy. This is very difficult to analyse at the end of the project though. So we discussed changing the interface to either (i) single binary questions about each galaxy, e.g. Bar or no bar? Smooth or featured? (ii) A survey project similar to the interface for Snapshot Serengeti which presents all the options for a galaxy at once, (iii) Lots of mini projects which are all offshoots of Galaxy Zoo focussing on one specific science question, or (iv) pairwise classification where we show two images of galaxies and ask which is more featured etc. There were many opinions about what the best way of doing this but we’d also love to hear your thoughts!

Later on we had an “alpha” test of a revamped Galaxy Zoo project which is survey style – it took people a while to get used to but people did seem to like it! There was also a lot of feedback but it was good to get the discussion flowing about what classifiers would like and what researchers would need.

There was also a discussion about how to study bars with the classifications from Galaxy Zoo. It’s a little difficult to pick stuff out, especially the weaker bars. One of the ways astronomers tend to find bars (e.g. when Galaxy Zoo classifications don’t exist for their sample!) is to fit light profiles to the disk of galaxies and take that model light off the original image. What you’re left with is called a “residual” – light that you didn’t account for, i.e. light from a bar. So there was a discussion about making an offshoot Zooniverse project classifying the residual light images to find weak bars.

Ross Hart then led a discussion about his new way of debiasing the Galaxy Zoo classifications to take into account the distance to galaxies and the fact that features get lost. He can recover lots more spirals with his new method. The table we link to on the Galaxy Zoo data page now has his debiased data table linked first.

We also had a discussion session about the outreach project Tactile Universe – which is a project engaging the blind community with astronomy. They’ve been 3D printing images of galaxies – the brightness being the third axis! We’d love to be able to make a tactile Galaxy Zoo but we have to wait for the tactile screen technology that we’d need to be able to do it! Looks like we’ve got our first session for our Galaxy Zoo Twentieth Anniversary Conference – watch this space #GZoo20.

Now we’ve finished up with the discussion all about the science, we get a treat at the end of the day! Our reward is that our very own Grant Miller has come to tell us all Tales From the Zooniverse! He’s telling us all about his first day on the job in the Zooniverse and how he realised it was going to be a great job when he went into his first meeting all about penguins with the Zooniverse’s Tom Hart! He is now showcasing how amazing the Zooniverse project builder is and is currently trying to build the original Galaxy Zoo project with it in under 3 minutes! And I can tell you: Reader, he managed it! He’s now telling us about his top picks for the Top 10 Zooniverse projects you’ve never heard of:

10) Monopole Quest
9) Expert Smooth/Not
8) Letters to Ryan
7) Bash The Bug
6) Faces of the World
5) The Planetary Response Network
4) Beluga Bits
3) Supernova Hunters
2) Family Certificates
1) Grant can’t name the top one! There’s so many on there now that Grant doesn’t know all of the projects on there (he used to know all the researchers of the projects but not anymore!) – 4700 new projects created since the project builder was launched. 47 of these have been fully launched as new projects, with 31 awaiting launch now.

His take home point: a LOT can happen in ten years!

Galaxy Zoo’s 10th Anniversary


Galaxy Zoo is celebrating ten years since launch next month, and as part of the festivities the science team are having a meeting in Oxford from 10th-12th July. Unfortunately we didn’t think it was feasible to invite the hundreds of thousands of you from all over the world who have contributed to the project over the last ten years, but the good news is that all of the talks from the meeting will be interactively live-streamed so that anyone can join in the discussion! See the schedule above for details on who is speaking at the meeting. Details of how to join the live stream will be released closer to the event.

There will also be an Oxford SciBar public event on the Monday night. All who are able to make it are welcome to join but don’t worry if you can’t, there will be a full podcast of the evening released shortly after the event!

Go West, Young (?) Astronomer

Many bargains must be made in pursuit of an academic career, and chief among them is an openness to a nomadic early-career life in exchange for a better chance at staying permanently put somewhere later. Grad students and postdocs move around. Not only do we travel all over the world sharing and discussing our research, but the relatively short duration of postdocs, and the fact that in astronomy doing at least 2 of them is now the norm, means we regularly pull up roots and dash off to live somewhere else. My friends have collectively done postdocs on all continents, including Antarctica. Including places thousands of miles from friends and family; including places where they can neither read nor speak any of the native languages.

In this context, I am so, so lucky. My first postdoc moved me only a medium distance (across just one ocean), and to a place where I could at least understand the words, even if I didn’t always get every nuance of meaning. At Oxford I made lifelong friends and built great collaborations, and I thought the research itself was pretty good, too.

Turns out NASA agrees with me. Last year I applied for and was awarded an Einstein Fellowship, which is an early-career award lasting 3 years, an independent postdoc that can be taken to any institution in the US. They’re very competitive (I had applied the previous year without success), and I was thrilled to be awarded one at my top-choice host institution. My first day was last week.

Here’s what the 2015 Fellows page has to say about my research plans:

Brooke uses a variety of multi-wavelength data, including highly accurate galaxy morphologies from the Galaxy Zoo project, to research the connection between supermassive black holes and the galaxies that host them. This connection appears to exist over many orders of magnitude in black hole and galaxy mass, but its fundamental origin is still a puzzle. As an Einstein Fellow at the University of California, San Diego, Brooke will investigate supermassive black hole growth in the absence of galaxy mergers, using a rare sample of galaxies which have never had a significant merger yet host growing black holes. These active nuclei, selected because their host galaxies lack the bulges which inevitably result from a galaxy merger, provide powerful leverage to disentangle the complex drivers of black hole growth and determine the origin of observed black hole-galaxy correlations.

During my fellowship I’m planning on moving forward with the research we first published in 2013 investigating bulgeless galaxies with growing black holes. That is: it’s Galaxy Zoo research.

Galaxy Zoo research brought me to Oxford, and now it has brought me to California. UCSD is a great place, and I’ve already made some really excellent scientists. UCSD is also part of the Southern California Center for Galaxy Evolution and has access to some of the world’s best telescopes, so the future is full of potential.

For now, though: I wouldn’t be here, watching sunsets from my office, without your contributions to Galaxy Zoo over the years. Thank you.