Too often science seems like a lofty ideal, a great and impossible muse that only those with years of education and impossibly high IQs (or at least a copious supply of white lab coats) can actually commune with. But then something like Galaxy Zoo comes along to turn that idea on its head.
Galaxy Zoo is a program that is driven by citizen science. Anyone with an internet connection, an eye for detail, and a bit of free time on their hands can help analyze images in a way that computers simply can’t and help researchers sort through oodles of data released by the Sloan Digital Sky Survey and the Hubble Telescope.
And those researchers need the help. The problem is that with modern technology scientists have just too much information to go through by hand, let alone analyze the results afterwards. It’s called the “Data Deluge” and is a major problem in modern astronomy. With enough human volunteers a process that would usually take a research team several years could be done in much less time, as little as a month with a large enough pool of people. And best of all, no astronomy knowledge is required.
But can volunteers with no professional knowledge really help further the cause of science? For that answer the best person to turn to is Hanny van Arkel, a Dutch school teacher and Galaxy Zoo volunteer.
In 2007 Hanny was perusing Galaxy Zoo, trying to decide if images represented spiral or elliptical galaxies, when she came across an odd image. Below a fairly normal image of a spiral galaxy she saw an odd swirling shape of blue. Being an active Galaxy Zoo forums user she posted the image to see if anyone else thought that it was odd, labeling it “Unidentified Bluey Stuff.”
Sure enough, she wasn’t the only one intrigued by the thing. Calling it a Voorwerp (Dutch for “object” or “thing”) the blue swirly soon got the attention of the astronomers in charge of the site. Being as they didn’t have the spectrum for it (and so were unable to tell if it was actually associated with the galaxy in the picture or just appeared that way) they approached Matt Jarvis over at the William Herschel Telescope in La Palma to see if they could get some better images. What they found was pretty amazing.
First of all, the thing was huge. The spiral galaxy in the second picture is at least the same size as our own… and the Voorwerp is even bigger. Not only that, but scientists quickly realized that it had a huge, clear hole right in the middle of it and some strange emission lines. Based on what they saw it looked as if parts of the Voorwerp were extremely hot, hotter even than some of the hottest stars.
Here were a group of research scientists with something that no astronomer had ever seemingly come across before. And they had no idea what it was. Soon the entire astronomical community was involved in the mystery, with a team of researchers securing time on the illustrious Hubble Space Telescope just to research it more fully. And, in case you were unaware, it is much easier to get time on television than on the Hubble.
And it wasn’t just the scientists working on the project this time; the “Zookeepers” included Hanny in the proposal and research process.
“The team is still working on it and until they’ve worked it out, I won’t even understand enough of it myself to explain anything on the matter. It is exciting however that the investigations have started and it’s nice to see how many curious people are sending me messages about it and ‘retweeting’ my quotes on Twitter. After almost two years, I’m very much looking forward to the outcome of all of this!” -Hanny in April of 2010
In January of 2011 they released their results to Seattle meeting of the American Astronomical Society. They discovered that stars were actually forming in part of the Voorwerp, likely due to gas collisions between gas flowing out from the neighborhood galaxy and gas within the Voorwerp. It’s the same sort of star birth that occurs in Minkowski’s Object, although the Voorwerp is nowhere near as violent as the Object (apparently the naming conventions for strange blue shapes that turn out to be birthplaces for stars are very strict).
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| Minkowski’s Object |
A closer look at the nearby galaxy showed that it had recently gone through some kind of odd interaction, with warped spiral arms and thick dust patches. It looked as if perhaps the galaxy had just merged with another and, even after approximately 200,000 years, the galaxy was still adjusting to its conquest. It looked like that merge is what caused the Voorwerp.
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| Hubble Shots |
“Putting it all together, here is the sequence of events that we think led to what we see today. Perhaps a billion years before our present view (which is itself 700 million years behind the times, and there’s nothing we can do about the speed of light), a merger led to IC 2497 forming from two progenitors, with its disk slowly settling but still warped. One product of this merger was an enormous tidal tail of gas, which came to stretch nearly a million light-years around IC 2497. During this process, material accreted into its central supermassive black hole, rapidly enough to produce the energy output of a central quasar as a byproduct, and illuminating and ionizing gas that was exposed to its radiation, to make the Voorwerp. About a million years before we see it, it started to blow material away (and this may have been when its radio jet and outflow started). Then, later still, the core faded, maybe as its energy output switched from being mostly in radiation to mostly powering the motion of material out of the galaxy. And now we see Hanny’s Voorwerp as a very lively echo of the past, as the last radiation from the fading core aces outward but has yet to complete the zigzag trip from galaxy to Voorwerp to us.”
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| Perhaps a diagram might help to digest that. |
So there we go. Dutch primary school teacher ends up making a huge discovery for the scientific community, furthering our knowledge of how stars form and galaxies merge. All because a couple of scientists decided to involve the public in their discoveries and because one volunteer spotted something just a little strange and wanted to find out more.
