Spiral Galaxies and the Future of Citizen Science: a Live Chat
Last week Karen Masters suggested that we start doing Galaxy Zoo live chats a little more often. I thought that sounded like a great idea, and we figured we’d just have an informal chat about whatever galaxy/Zooniverse topic we felt like discussing that day.
We were joined by Kyle Willett and Kevin Schawinski, and the four of us started talking about this paper, which presents an automated system for classifying and measuring spiral arms. It compares to Galaxy Zoo 2 data within the text, and we talked about what the fact that the computers did pretty well means for the future of Galaxy Zoo. We didn’t prepare anything in advance, and I didn’t even start reading the paper until about 20 minutes before we got going. So my favorite part of the chat is where I put forward a few definitions of pitch angle and get them all wrong. Science in action!
We also introduced the jargon gong, which we used on each other whenever one of us said something in insider-speak. I think this is a feature worth keeping, and we also plan to invite viewers to gong us themselves via Google+ or Twitter for the next chat.
When will the next chat be? We’re not sure yet, but hopefully soon — I promise I’ll even try to make a blog post before we start next time!
Update: We’ve now extracted the audio into an mp3 file and started a podcast:
Galaxy Zoo 2 at the AAS meeting
This post was written by Kyle Willett. He is a postdoc at the University of Minnesota and a member of the Galaxy Zoo science team.
It’s been a couple of weeks since the 221st meeting of the American Astronomical Society (AAS) in Long Beach, California. Kevin and Bill already made several excellent posts on their conference experience (tip: showing data hot off the telescope and having Swiss chocolate at your poster really generate foot traffic). I wanted to write a bit more about the research that I presented and how it related to other topics at the meeting.
My poster was up during on the third day of AAS, in the “Catalogs” section of the big poster hall. This is a bit unusual in that the posters there were sorted more by their methods, rather than science content. A group like this is useful for identifying projects with similar challenges, including curation of large data sets, reduction techniques, and how to best publish the data so the scientific community will recognize and use it. The content varies widely, though – I got to compare what galaxy morphologies might have in common with catalogs of bright stars, exoplanets, and infrared mosaics.
Kyle Willett (@kwwillett) talking about GZ2 with Nicole Gugliucci (@NoisyAstronomer). Photo by W. Keel.
The content of my poster focused on three topics. The first was a description of the Galaxy Zoo 2 project, describing the new questions we developed (and that you answered) and the sample of galaxies in the Sloan Digital Sky Survey that the results cover. This is slightly different from the original Galaxy Zoo, since GZ2 uses a brighter sample of galaxies in which more detail can be seen.
The second portion was my work on data reduction for the Galaxy Zoo 2 catalog; in particular, the way in which we demonstrate that more distant galaxies appear smaller and dimmer in the classification interface, and how this can be corrected. I showed data for 4 of the questions (smooth vs. features? is it an edge-on disk? is there a bar? are there spiral arms?) as examples of successful corrections that we’ve already done. The remaining 7 are being finished this week, with results looking good so far.
Finally, I had a section summarizing the science results from using Galaxy Zoo 2 data. So far, these have all been led by members of our own science team (which you can find here). Our goal in releasing the full catalog, though, is to make GZ2 a community resource – we want other groups to use the data and write even more interesting papers. We know we have a unique data source – the challenge is to reduce it properly, put it in a useful public format, and help publicize it by writing papers and attending conferences.
I had a lot of good conversations with other astronomers at this meeting, many of whom are very keen to see the data come out. Several interesting presentations raised questions we can explore with GZ2. I was intrigued by Michael Rutkowski’s (Arizona State) talk on the surprising amount of star formation and diversity amongst early-type galaxies, as well as Benjamin Davis’ (Arkansas) talk on using computers to measure the angle of spiral arms and how it relates to their central black holes.
Overall, it was a great meeting both for general astronomy and for Zoo-related projects. The science team and I are finishing the first draft of the data release paper this month, and we’ll be submitting it to a journal shortly after. I’ll keep writing as we make progress – as always, thanks for your classifications that make my work possible!
How to get people to read your poster
3000 astronomers will bring down the wireless in any building, so I have been a bit behind in posting from the American Astronomical Society meeting in Long Beach CA…
Bill with the poster.
Yesterday, Bill Keel presented a poster with the latest Hubble observations of the Voorwerpjes in the Giant Room Full of Posters, where astronomers, pretty much ALL of who work on absolutely cool stuff, present their results. So, anything you can do to get peoples’ attention helps! I decided to bring along some chocolates from Switzerland. If any unwary astronomer walked past and took one, they then had to at least look at the poster… ; )
Most of the chocolate is already gone!
UGC 7342 and the Hubble Voorwerpje roundup – can they get any weirder?
As usual when the American Astronomical Society meets, this has been an intense week of research results, comparing notes, and laying plans. Galaxy Zoo has once again been well represented. Here’s Kevin discussing the Green Valley in galaxy colors, making the case that it consists of two completely different populations when Galaxy Zoo morphologies are factored in:
Kevin makes his case
Today we’re presenting first results of the Hubble imaging of Voorwerpje systems. This is what our poster looks like:
AAS poster paper on Hubble Voorwerpje data
(or you can get the full-size 2.8 Mbyte PDF). We didn’t have room to lay out all the features we first had in mind, but these are the main points we make:
They show a wild variety of forms, often with filaments of gas stretching thousands of light-years. These include loops, helical patterns, and less describable forms.
The ionization, traced by the line ratio [O III]/Hα, often shows a two-sided pattern similar to the ionization cones around many AGN. This
fits with illumination by radiation escaping past a crudely torus-like structure. However, there is still less highly-ionized gas outside this whose energy source is not clear.
As in IC 2497, the parent galaxy of Hanny’s Voorwerp, many of these galaxies show loops of ionized gas up to 300 light-years across emerging from the nuclei, a pattern which may suggest that whatever makes the nucleus fade so much in radiation accompanies an increase in the kinetic energy driving outflows from its vicinity.
At the bottom of the poster we illustrate with new clarity a point we knew about in the original paper – for the two Voorwerpje systems with giant double radio sources, they completely break the usual pattern of alignment between the radio and emission-line axis. Mkn 1498 and NGC 5972 are aligned almost perpendicular, which can’t be fixed by changing our viewing angle. We’re speculating among ourselves as to how this could happen; maybe interaction of two massive black holes is twisting an accretion disk. But don’t quote me on that just yet.
The color images here show only the ionized gas, with [O III] in green and Hα in red. Starlight from the galaxies has been subtracted based on filters which don’t show the gas, so we can isolate the gas properties. The false-color insets show the [O III]/Hα ratio. The blank regions are areas whose signal is too low for a useful measurement. Red indicates the highest ionization, fading to deep blue for the lowest.
We were able to feature some new data that came in too late to be printed in the poster (by tacking up a smaller printed panel) – the long-awaited images of UGC 7342, among the largest and most complex clouds we’ve found (or more correctly, so many Galaxy Zoo participants found). Hubble observed it Monday afternoon, and after some frantic file-shuffling and processing, I got the data in the same shape as the others. And here it is:
UGC 7342 Hubble image
Click on this one to see it larger. We barely know where to begin. The actual AGN may lie behind a dust lane, and there is a large region of very low-ionization as near it. Another loop near the nucleus, and fantastically twisted filaments winding their way 75,000 light-years each way.
There is still more to come – with Vardha Bennert and Drew Chojnowski, we planned the strategy for several upcoming observing runs at Lick Observatory (one starting only next week). These should include getting data on some of the most promising AGN/companion systems to look for the AGN ionizing gas in companion galaxies, and observation of regions in the Voorwerpjes that we only now see a context for. Additional X-ray and radio observations could fill in some of the blanks in our understanding. And by all means, stay tuned!
Good Things come at the same time
AAS meeting update!
The last 24 hours have been good for Zoo team member Bill Keel (@ngc3314) is based at the University of Alabama. Not only did his University football team win some sort of championship (they all look the same to Europeans) last night, but the Hubble Space Telescope observed the final Voorwerpje in our approved programme! That means Bill was probably glued to the TV and downloading and reducing the data at the same time!
He’ll add the reduced image to his poster at the AAS meeting, so if you want to see the image, come join us at the poster tomorrow! He may also blog it some time later, but for the FIRST look, you’ll have to come to the poster! There may be chocolates too….
The poster is: 339.47. HST Imaging of Giant Ionized Clouds Around Fading AGN, up all of Wednesday from 9-6.
The Galaxy Zoo Team goes to Long Beach CA
It’s January and that means that astronomers from all over the world flock to the American Astronomical Society‘s annual winter meeting (Jan 6-10 2013). This year, the 221st meeting, is in Long Beach CA. Quite a few of the team members and collaborators are going to the meeting and we’ll keep you posted on the exciting results that we’ll be presenting here on the blog and via our twitter account at @galaxyzoo.
The following talks by the team will be happening:
I’ll (@kevinschawinski) be talking about how blue galaxies turn into red ones (I needed all the blue ellipticals and red spirals you all found!) and how the two processes are completely independent. The talk is based on a paper in progress that I’m hoping to get ready for submission soon.
Kyle Willett (@kwwillett) will present an update on the reduction and analysis of the Galaxy Zoo 2 data. How do we turn your clicks into galaxy classification? This is the talk that will explain it!
Brooke Simmons (@vrooje) is going to update us on how bulgeless galaxies spotted by you! managed to grow enormous 10 millions solar mass black holes at their centers entirely through `gentle’ or `secular’ processes. No major mergers here!
Sugata Kaviraj will talk about the formation of early-type galaxies in the first half of cosmic time and discuss how your clicks from the ongoing Hubble Zoo might help uncover their secrets. And about how to get short term loans when you’re a student of the universe.
Finally, Bill Keel (@ngc3314) will present a poster with the latest analysis of the Hubble data of the Voorwerpjes, the light echoes of dying black holes.
Our friends from the Planethunters team are also going and may have some exciting news up their sleeve as well!
