9 Years of Galaxy Zoo

Last year we had so much fun celebrating all that we (including you) had accomplished over the first 8 years of Galaxy Zoo. This year, for our 9th birthday, we thought we’d hand things directly over to you. We sent out a newsletter asking people about their favorite Galaxy Zoo science. We asked people to rank five choices:

  • Hanny’s Voorwerp & the Voorwerpjes (ionized clouds and active galaxies)
  • Green Peas (highly compact & star-forming galaxies)
  • Red spirals (disk galaxies with no/little star formation)
  • Blue ellipticals (spheroid galaxies with ongoing/retriggered star formation)
  • Bars (the galaxy kind; how this mode of disk galaxies drives galaxy evolution)

We’ve now collected just over 200 responses and combined your rankings. Although the distributions were pretty similar, and all the options had plenty of people choosing it as their favorite, one of the options jumped out as a pretty clear leader (at least in this rather informal poll).

Bars - the galaxy kind!

Bars – the galaxy kind!

Of course, the list we asked people to choose from is by no means complete, especially if you include not just the main Galaxy Zoo but also its related projects. In the “Other” box we had a variety of entries, with some mentioning galaxies found in Radio Galaxy Zoo and others citing those seen in Galaxy Zoo: Bar Lengths. Plenty of people mentioned galaxy mergers, and gravitational lenses got a few mentions too! If we had a complete list the rankings would likely be different, but then again, that would be such a long list I’d be worried many fewer people would want to answer.

We also had a space for people to enter whatever text they wanted at the end of the survey, and the responses were varied, interesting, and a treat to read. Here’s a sample (each paragraph is a separate comment):

I do not spend a lot of time here, but when I have the time, I love it. Thank you!

What a great way to feel like a scientist.

I’ve been an on-and-off participant in the Zooniverse citizen science projects since I was 13 years old – and Galaxy Zoo has been one of my favourites for a while! I just wanted to say thank you for providing the opportunity for an ordinary teenager to feel included in fascinating scientific research – that experience has inspired me to pursue a degree in Physics and Astronomy in the fall.

Go Science!

We were also curious about who, as a group, we were asking these questions of. It turns out that quite a large fraction of people who responded to the survey have been with us since the early days, which is so lovely. And we were also delighted to see people engaging with us who’ve just recently discovered Galaxy Zoo. We are so glad all of you are collaborating with us; here’s to many years to come.

Thank you!

P.S. – The big 10 is coming next year… what would you like to see for the occasion?

Galaxy Zoo and the COSMOS Survey.

galaxies

Hello present, and hopefully future volunteers!

I’m a summer research intern on the Zooniverse Project, based at the University of Oxford. I’m currently at university in London and I’ll be going into my fourth year of studying Theoretical Physics. I’m three weeks into my internship, and I want to share with you how the hundreds-of-thousands of galaxies you’ve worked hard to classify are being used in research.

I’m working with Galaxy Zoo Hubble (GZH) data, which are classifications of galaxies from the Hubble Space Telescope Legacy survey. The classifications for this data have just been submitted for publication by a group of researchers from Galaxy Zoo, and you can read about it here. Specifically I’m working with a subset of this data from the Cosmic Evolution Survey, or COSMOS. This survey is specially designed to help us understand how galaxies evolve over time, and how their local environments in the universe affect this.

Up to now I’ve been using GZH data to add morphology to data currently found in the literature, in the hope that we can learn something new about galaxy evolution. In this post I want to share with you a particular striking example of how GZH classifications have transformed current data. Figure 1 shows two rows of colour-colour plots. The vertical axis is U-V colour, which is a measure how much recent star formation is going on in a galaxy – the higher up a galaxy is in the plot the more recent star formation is going on. The horizontal axis is V-J colour which is a measure of how much Infrared light compared to visible light a galaxy is emitting – the further left a galaxy is in the plot the generally older and more ‘dead’ it is. The first row (top) is found in a paper (Muzzin et al 2013), on analysis of galaxies in the COSMOS survey, written by researchers from the US, Denmark, Netherlands, UK, and Chile. The second row (bottom) shows the same data but with GZH classifications overlaid. Red and blue points represent featured and smooth galaxies respectively. Banner image shows a featured spiral galaxy (left), and and smooth elliptical galaxy (right).

Figure1

Figure 1: colour-colour plots Galaxies from the COSMOS survey (top) before (bottom) after GZH classifications data added. Red and blue points represent featured and smooth galaxies respectively.

No need to ask which one looks more interesting! Lets understand what these plots mean. Each point on each plot represents a different galaxy. On each row the plots are sorted by z or redshift; you can think of this as being different snapshots of galaxies in the universe at different times. The most recent snapshot being on the left, and the oldest on the right of each row.

The important thing to take away from this data is that there are two distinct blobs or populations of galaxies in each plot. Galaxies in the top left blob are called star forming (SF) and galaxies in the longer bottom right blob are non-star forming, or ‘quiescent’. From the overlay of GZH classifications data on Figure 1 (bottom), we can see that the nearly complete absence of galaxies with features in the top left population of SF galaxies – something that we didn’t know before!

So why do we care about analysing colour-colour plots of galaxies? As a galaxy evolves through its lifetime it moves from the SF population to the quiescent through that bit in-between the two blobs, which is called the ‘Green Valley’ (I’ll save more on that for another blog post), and the truth is nobody quite knows how this happens. Overall, we hope GZH classifications may shed some light on this, and help us understand how galaxies evolve.

To help us finally understand the evolution of galaxies, get involved right now at www.galaxyzoo.org, we’d be happy to have you on-board!

@petermcgill94

A new paper about spiral galaxies in Galaxy Zoo

I’m happy to announce that my first Galaxy Zoo paper has been published! You may be aware that I recently posted about spiral galaxies in Galaxy Zoo (the blog post can be found here). The first results from these studies have now made it to publication, where we discuss a new method for removing bias in galaxy classifications, as well as comparing the properties of different spiral galaxies.

spirals

Some example 1, 2, 3, 4 and 5+ armed spiral galaxies classified in Galaxy Zoo.

As discussed in my earlier blog post, spiral galaxies are some of the most interesting galaxies in the local Universe. However, studies of these objects have been limited, due to the fact that galaxies need to be visually classified. It is therefore thanks to all of the volunteers in Galaxy Zoo that a paper like this can be published, where we have thousands of spiral galaxies to compare. Thanks to these classifications, we have been able to find some interesting preliminary results: we find that many-armed spiral galaxies are bluer in colour than two-armed spiral galaxies. This suggests that many-armed spirals are sites of significantly enhanced activity in the Universe, where high levels of star formation activity are taking place.

cc1

Colours of spiral galaxies by arm number. Lower u-r  and r-z mean galaxies are bluer in colour (many-armed galaxies show bluer colours).

However, these results are only a hint at what we can achieve in the future. So watch this space and we’ll keep you all informed about any developments in our work on spiral galaxies!

If you are interested in reading more, the full article can be found here.

 

Discovered galaxy cluster named after two citizen scientists

This post was written as a contribution by Timothy Friel, an undergraduate Australian National University student studying Theoretical Physics and Science Communication. Tim is conducting research into citizen science projects and their social media communication strategies.


Hats off to two of our volunteer participants who have officially been written in the stars.

The Matorny-Terentev Cluster RGZ-CL J0823.2+0333 bears the name of the two citizen scientists who pieced together its structure.

Ivan Terentev and Tim Matorny, two Radio Galaxy Zoo participants from Russia, discovered that a particular radio-source had a line of radio blobs delineating a C-shaped ‘Wide-Angle Tail galaxy’ (WAT). The massive galaxy hosting the super-massive black hole and its associated jets are moving through intergalactic gas, causing the jets to fold back, similar to the way a sky-diver’s hair is shaped by the wind.

giantWAT-pink-zoom

Figure 1: The new discovery: The C-shaped “wide angle tail galaxy” (pink) surrounded by the galaxies of the Matorny-Terentev cluster (white). Julie Banfield, Author provided

This discovery has been published this week in the prestigious scientific journal Monthly Notices of the Royal Astronomical Society, with the paper “Radio Galaxy Zoo: discovery of a poor cluster through a giant wide-angle tail radio galaxy” (accessible for free via bit.ly/RGZpaperWAT).

Lead author of the study, Dr Julie Banfield of CAASTRO at The Australian National University (ANU), said that the discovery surprised the astronomers running the program.

“They found something that none of us had even thought would be possible”, said Dr Banfield.

More details of the research team’s response and the next steps for the project can be read in the press release published by CAASTRO (bit.ly/PR14June16).

A huge congratulations must go to the two citizen scientists, Ivan and Tim, for their efforts to work collaboratively to make this discovery. It is great to witness that physical and language barriers have been unable to halt amazing scientific endeavours.

A further thank you must also be noted for the Radio Galaxy Zoo team, in particular the joint project leaders Dr Julie Banfield (ANU) and Dr Ivy Wong (ICRAR at UWA), alongside Dr Anna Kapinska (ICRAR at UWA), Dr Ray Norris (CSIRO/WSU) and all other members of the international project. The team’s continued energy to motivate volunteer participants to develop their own research projects has uncovered the immense potential of citizen science as both a research tool and a method of bringing people together across the globe.

Finally, the Radio Galaxy Zoo team would like to thank the 10,000 volunteers globally who have volunteered to conduct over 1.6 million image classifications over the past two and a half years. The dedication of volunteers to this project has bred a supportive community which has now completed almost 60% of the dataset, a feat unable to be achieved by any single individual.

If you would love to become involved in this international astronomical community, please head to bit.ly/RadioGalaxyZoo1 and begin your journey to uncover the depths of our universe and its wonders, all from the comfort of your own home.


ANU: Australian National University
CAASTRO: Australian Research Council Centre of Excellence for All-Sky Astrophysics
CSIRO: Commonwealth Scientific and Industrial Research Organisation
ICRAR: International Centre for Radio Astronomy Research
UWA: University of Western Australia

Kyle’s Legacy

Screen Shot 2016-05-31 at 10.55.36

Good news! Early this morning UK time, we submitted the paper describing the finished data release for the third iteration of Galaxy Zoo to the journal Monthly Notices of the Royal Astronomical Society. It’s taken an enormous amount of work to get to this point, in particular in understanding how to account for the effects of distance on classifications. Most of that work was done by Kyle Willett and Mel Galloway from the University of Minnesota (Kyle gave a sneak preview here), and it was finished just in time because Kyle leaves us tomorrow.

Kyle and friend at his leaving party.

Kyle and friend at his leaving party.

Kyle has had an enormous impact on Galaxy Zoo since he came on board in 2011. As well as publishing papers on star formation and the enormous data release paper for Galaxy Zoo 2, he’s been the person making images, coordinating what’s seen on the site and keeping an eye on classifications as they’ve come in. Just as importantly, he’s been a prolific contributor to this blog, playing a leading role in keeping our important collaborators, the volunteers, in touch with what’s going on. It’s not just Galaxy Zoo, either, as Kyle has also played a critical role in the Radio Galaxy Zoo team, and has made major contributions to their recent papers too. He will be much missed by all of us, though we wish him well with his future endeavours.

Upcoming Galaxy Zoo: Hubble and CANDELS papers

It’s been a good amount of time since the Galaxy Zoo: Hubble and Galaxy Zoo: CANDELS projects were finished, tackling more than 200,000 combined galaxies thanks to the efforts of our volunteers. While we’ve had a couple of science papers based on the early results (Melvin et al. 2014, Simmons et al. 2014, Cheung et al. 2015), a full release of the data and catalog has taken slightly longer. However, we’ve been working hard, testing the data, and developing some new analysis methods on both image sets. This month has been really exciting, and we now have drafts for both papers that are just about finished. Once they’ve been accepted to the journals (and revised, if necessary), we’ll have some much longer posts discussing the results, and of course attaching the papers themselves. Hopefully that’ll be quite soon.

As a small teaser, here’s a little movie I just made of the Galaxy Zoo: Hubble paper as it went through the various drafts by different members of the science team. If only all paper writing were this easy …😉

How to write a Galaxy Zoo paper in 15 seconds ...

How to write a Galaxy Zoo paper in 15 seconds or less … (Image: K. Willett)

Models of Merging

Once upon a time, there was an experimental project called Galaxy Zoo: Mergers. It used ancient, mystical technology to allow volunteers to run simulations of merging galaxies on their computers, and to compare the results of many such simulations. Their mission: to find matches to more than fifty nearby mergers selected from Galaxy Zoo data.

The wonderful Penguin Galaxy, studied in the project.

The wonderful Penguin Galaxy, studied in the project.

Amongst the chosen galaxies were not just run-of-the-mill, everyday mergers, but also the various oddities that the volunteers found, such as the Penguin galaxy. The team led volunteers through a series of tournaments designed to pit potential solutions for a particular galaxy against each other. In total, more than 3 million simulations were reviewed producing the results described in the paper, now accepted by the journal MNRAS, and in the dataset visible at the main Galaxy Zoo data repository. This represents a huge amount of effort, and a speeding up of the process – in the paper, we note that previous fits to mergers have taken months of effort to complete.

Which is not to say the analysis, led by Anthony Holincheck and John Wallin, has been easy. In a recent email to the Galaxy Zoo team, John commented:

This is by far the most complex project I have ever worked on. Most papers that model interacting galaxies contain one or two systems where the author uses a few dozen simulations. We just published a paper that modeled 62 different systems using a brand new modeling technique where the 3 million simulation results were reviewed by citizen scientists. Best of all, the 62 models were done using the same code and the same coordinate system so others can reproduce them. Doing this with other published simulations is nearly impossible.

I know an immense amount of effort went into making sure that the results weren’t wasted, and the paper thus represents a happy ending to a tale that’s been running a long time. But it is not really an end; we are already planning to observe some of these galaxies as part of surveys like MaNGA that can measure the way that the galaxies’ components are moving today, allowing us to test these models. We also hope a library of models might be useful for other astronomers, and will be looking to try and revive this kind of project.

Read more about Galaxy Zoo: Mergers in this old blog post blog.galaxyzoo.org/2012/03/27/the-finale-of-merger-zoo.

Exclusive interview with our recent Citizen Science co-authors

This post was written as a contribution by Timothy Friel, an undergraduate Australian National University student studying Theoretical Physics and Science Communication. Tim is conducting research into citizen science projects and their social media communication strategies.


Meet two of our fantastic Zooniverse members who have been recognised as co-authors for a RGZ submitted paper.

In March 2016, the Radio Galaxy Zoo (RGZ) team submitted a paper which is co-authored by two of our SuperRGZooites. Thanks to the help of citizens around the world, over 1.6 million classifications have been made. However, a very special thanks must go to two citizens who have been greatly involved in our most recent submitted paper.

19MAR2016

Meet Ivan Terentev and Tim Matorny, our Citizen Science co-authors.

How did you discover Radio Galaxy Zoo and become involved?

Tim: I had a passion for research and to be involved with generating new knowledge. So I began to look and met [the world of] citizen science and tried many different projects. I was already familiar with the Zooniverse, when I got email about new project – RGZ.

Ivan: I became involved in RGZ from its beginning, more or less, in December 2013, and at that time I was part of the Zooniverse for two years. I was mostly contributing to the Planet Hunters project back then, but occasionally I switched to different projects just to look for what they have to offer. And it was during one of these “Let’s try something different” moments that I discovered RGZ through the announcement post in the Galaxy Zoo blog.

What parts kept you interested and motivated to stay a part of this project?

Tim: The team of scientists and their active participation is an important part. Their blog posts, comments and links have helped me to learn about the project and my involvement with the goals.
Looking for host radio lobes which are separated by a 10′ [minutes] or looking at the behaviour of jets in galaxies clusters is really exciting for me. I like that RGZ covers a wide range of data: radio, optics, IR, X-ray.

Ivan: If we are talking specifically about RGZ, it would be the RGZ Talk community and the fact that RGZ Science team is eager to communicate with simple volunteers and involve them in the research process. But a large portion of my motivation [for RGZ] is the same as for the rest of the Zooniverse projects. You see, I am sci-fi fan and it made me interested in space exploration. I like to watch documentaries about the astronomers, their work and all the amazing stuff in the universe around us and through the Zooniverse I can actually be involved in the process of science and help to shape the future, even if it just by a very tiny fraction. I never thought that something like this would be possible before I discovered Zooniverse.

How do you feel about being a co-author of a scientific research paper?

Tim: I am still amazed and feel more motivated to look for stunning new radio galaxies.

Ivan: This isn’t the first time actually, I am also a co-author for three papers from the Planet Hunters, BUT it is always awesome, like every single time! Although, I keep my head cool over that since most of the work was done by the professional scientists. A huge thanks to them for the acknowledgment of my small contribution in the form of inviting me to be a co-author in their paper. With this RGZ paper, I got a chance to see the whole process of science starting from the simple question “What is that?” and then people trying to figure out what is going on, schedule observations, discussing things and I have been a part of it! All the way through the process, ending with the actual published science article. It was an amazing experience!


Without the contributions made by our volunteers all over the world, we would not have been so successful in our endeavours.

However, we have only reached 57% of our classification target. Head to www.bit.ly/RadioGalaxyZoo1 to become involved and you could be co-authoring another great discovery with us!

New galaxies in Galaxy Zoo

We’re excited to announce the launch of two new image sets on Galaxy Zoo.

Recently your work has helped us classify 34,429 images coming from the DECaLS first data release (DR1). With the release of DECaLS second data release (DR2) we have added 61,595 new galaxies into Galaxy Zoo. DR2 covers a larger portion of the sky than DR1, and has better quality and deeper images then SDSS. These galaxies are taken from the NASA-Sloan Atlas (a catalog of over 140,000 local galaxies in both the optical and UV) and focuses on the larger and brighter galaxies not already covered by DR1, in addition to the galaxies imaged by an extra year’s worth of data.

J000720.93-032245.6

Example galaxy taken from DECaLS DR2 sample.

Our second image set, appropriately named “the lost set”, is made up of 25,529 SDSS images that should have been included in Galaxy Zoo 2. These galaxies also come from the NASA-Sloan Atlas, but for one reason or another never made it into Galaxy Zoo until now. Once classified, these images will fill in the hole that currently exists in the bright galaxy data set. These SDSS images are in the queue and will go live sometime later this year, depending on the progress being made on DECaLS DR2.

J000005.00-051233.9

Example galaxy taken from “the lost set”.

Spiral galaxies (and why Galaxy Zoo is perfect for their study)

My name is Ross Hart, and I am a second year PhD student at the University of Nottingham using Galaxy Zoo data to study spiral galaxies. I am keen to write some blog posts about these galaxies, which are not only elegant in appearance, but also have a lot of interesting physics associated with them. In this first post, I will give a brief overview of spiral galaxies, and why Galaxy Zoo could be an important tool for their study.

m51_ngc_1232

Two-armed spiral galaxy M51 (left) and many-armed galaxy NGC 1232 (right). Image credit (M51): X-ray: NASA/CXC/SAO; Optical: Detlef Hartmann; Infrared: NASA/JPL-Caltech Image credit(NGC 1232): X-ray: NASA/CXC/Huntingdon Institute for X-ray Astronomy/G. Garmire; Optical: ESO/VLT

Spiral galaxies are the most numerous type of galaxy in the local Universe, with approximately 2/3 of local galaxies exhibiting spiral arms. Most of the gas and young stars in the disks of spiral galaxies are located in spiral arms, giving the appearance of the beautiful spiral patterns observed in galaxies such as M51 and NGC 1232 (shown above). However, the reason as to why we study these galaxies is not simply because they are pleasing to the eye; most of the star-formation in the local Universe occurs in spiral galaxies, so understanding the physics of spiral galaxies holds the key to understanding how stars form in galaxies.

Despite the relative prominence and importance of spiral galaxies, we still do not have a good understanding of how spiral galaxies form and evolve. Much of the problem as to why this is the case is that ‘spiral’ is actually far too broad a term to describe galaxies with different types of spiral structure. In particular, most galaxies have two spiral arms in a grand design spiral structure, like that of M51. However, some galaxies have many spiral arms, like NGC 1232.  However, the difference between M51 and NGC 1232 are actually thought to be much deeper than simply the number of arms that the two galaxies have; the physical processes that are responsible for their formation is also thought to be very different.

In order to study spiral galaxies in any level of detail, we require a method of classifying galaxies by the type of spiral structure they have, which requires detailed morphological classifications. It is for this reason that Galaxy Zoo provides an exciting opportunity to compare spiral galaxies in a way that simply hasn’t been possible before. Thanks to all of the volunteers who helped to classify galaxies in Galaxy Zoo 2, we have access to a  sample of spiral galaxies classified with unprecedented size. All of these galaxies have been classified by arm number, so we have the ideal tool for investigating how these different spiral structures form in a level of detail that hasn’t been possible before.

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