A Busy Galaxy Zoo Day
Sometimes in scientific research opportunities collide and lead to rather busy days. Yesterday I had such a day, and since it involved me giving two presentations about Galaxy Zoo I thought you might be interested to hear about it.
In the morning I gave a talk “Galaxy Evolution in the Galaxy Zoo” at the “Unity of the Universe” conference in Portsmouth, a conference celebrating the opening of the new Dennis Sciama Building for the Institute of Cosmology and Gravitation (ICG, where I and several other “Zoo Keepers” work). This talk was aimed at summarizing for astronomers and cosmologists at the meeting the exciting results on galaxy evolution which have come out of Galaxy Zoo. Many researchers in astronomy are aware of Galaxy Zoo, and in general are very interested in it, but they tend to think of it more an an opportunity for outreach with the interested general public and less in terms of the exciting science which can come out of it. The point of my talk was to say that it should in fact be viewed as both. It seemed to go over well.
Over lunch I took a train to London where in the afternoon I was interviewed by an esteemed panel of scientists (including Baroness Susan Greenfield, Director of the Royal Institution, and Prof. Alec Boksenberg, Chair of the UK National Commission for UNESCO). This interview was because I was a finalist in the competition for the 2009 L’Oreal UNESCO UK/Ireland Fellowships for Women in Science. My proposal for this fellowship (for £15000) was to extend my period of study at Portsmouth so I could spend more time studying the red spirals in Galaxy Zoo (among other things). I gave a 10 minute talk about this proposed research, then answered questions from the panel.
Later that afternoon I had a L’Oreal makeover (really – but don’t worry this was not a requirement for the fellowship just a treat, and a positive sign in my opinion of a recognition that scientists can want to be feminine) and in the evening I attended a reception at the Royal Institution at which the winners of the fellowship were announced. Unfortunately I did not win the competition, but as I did make the final 8 (out of 240 applicants) I can’t feel too bad about it. I also got a nice engraved pen, met some very interesting people, and I’m assured I can still expect some free makeup. So that’s not too bad after all!
Quite a busy day in the life of an astronomer!
She's an Astronomer: Alice Sheppard
Alice Sheppard has had various jobs in administration, environment, teaching and writing whenever she can – but as soon as she started moderating the Galaxy Zoo Forum nearly 2 years ago, she knew that this was her real work. She’d been hooked on astronomy and science since she was very young, but the presentation of these subjects at school didn’t encourage her to think she’d ever really get involved. She studied Environmental Science at university in Norwich and Granada, Spain, and became increasingly interested in informing and involving the public. She now lives in Pembrokeshire, Wales, with her family and two cats who also contributed to scientific research for April Fool’s Day! Her involvement in the Galaxy Zoo project inspired her to start an Open University course and her current goal is to continue the work she has begun informally in the Galaxy Zoo project as a science communicator and educator. You can catch up more with Alice on her blog: Alice in Galaxyland, and she invites you to join her any time for virtual coffee and galaxy conversations in the forum.
Questions about Cosmology?
A group of young cosmology researchers at the University of Portsmouth (where a number of Zoo people work) are trying to start a video podcast outreach project. The working title is “Our Universe” and the idea is that these would be short video podcasts, probably released on You Tube which will give some insight into how cosmologists/astronomers work as well as answer some basic questions about the science. I’ve seen a rough draft of the “pilot episode” and it’s quite fun.
One idea is that each episode would include short (ideally around 10 seconds) video or audio clips from members of the public asking questions of scientists. These can be questions about the science, or about their jobs, or whatever you want really. We were hoping that some Zooites reading this blog might be interested in helping out with this as a test run – and you might get to appear in one of the early episodes if it all works out. Be warned – if the clip is too long it’s much less likely to be useful. Short and to the point questions are what’s needed here.
So if you have a burning question to ask a cosmologist and you have the ability to make a short video (with a webcam for example) or audio clip (plus accompanying picture) of yourself asking this question that would be great. For now we’ll use the University of Portsmouth Web Shelf to share the files – if you upload something post a comment here with the URL and I’ll grab it (don’t worry it’ll expire a week after you upload it).
Thanks in advance for your help, Karen.
Unveiling the Mass of Galaxies with Vera Rubin
This week I am attending a conference at Queen’s University in Kingston (Ontario, Canada) with I think the longest name I have ever seen. It’s called “A Celebration of Vera Rubin’s Life. Unveiling the Mass: Extracting an Interpreting Galaxy Masses.” I was very excited to attend this conference. Vera Rubin has always been a role model of mine (hard to avoid as a women studying galaxies) and as well as her the list of speakers includes many people who’s work I know and respect. It also has the advantage of being held in Kingston where a close friend (and fellow astronomer) from graduate school is now living with her very new baby.
This morning the introductory talks did not disappoint. We heard anecdotes from Vera Rubin about her work as a young scientist just trying to interpret the observations she was making on the rotation curves of galaxies (observations that provided the first strong evidence for dark matter in galaxies). She talked about a 1962 paper she did with students measuring the rotation curve of the Milky Way, and her regrets on not noticing that dark matter must have been present when she measured a similar “flat” rotation curve for the Andromeda galaxy 13 years later. She further impressed me by dating another anecdote (about discovering a galaxy in which the stars rotated in two directions) by the year her youngest child learned to walk (1961). Not only is Vera Rubin an incredibly successful and famous astronomer, but she managed to have 4 children (at least one of whom followed her into astronomy) during the period she did most of her famous work. Wow! I got to talk with her a little bit this morning at coffee, and she’s also a very nice person.
As well as enjoying the many talks by leaders in the field of galaxy evolution, I am presenting a poster on my work on dust reddening of Galaxy Zoo spirals which you have heard about several times before (eg. Blue Sky and Red Spirals, and from when I presented it at the 2009 European Week of Astronomy). This work has relevance to the masses of galaxies as dust is a significant source of error on estimates of the total mass of stars in a galaxy – at the simplest level dust hides the stars.
I was encouraged to share my poster on this blog, so if you wish to have a closer look at it you can download it (pdf). Of course this poster is aimed at explaining my work to other astronomers not to a general audience. If you have questions about it I encourage you to first look at my more general explanation of the work Blue Sky and Red Spirals and I am also happy to answer questions in the comments below.
One little details which is not explained in the poster is that the images of galaxies on both the right and left are not random. On the right I show edge-on spiral galaxies ordered from bluest (at the bottom) to reddest (at the top). On the left I show all face-on galaxies, also ordered in the same way. My definition of blue versus red comes from a measured difference in the brightness seen through 2 filters (in this case the SDSS g and z filters), so is not always obvious to the eye – also remember that it is the average colour of the whole galaxy, and some have significantly different colours in their centres to in the outskirts. However one of the interesting results coming from this work is that even though on average dust reddens galaxies as they become more inclined (as they go from face-on to edge-on) some face-on galaxies are much redder than some edge-on galaxies. This shows that while dust is important to the colour of a spiral galaxy it is clearly not the most important factor. This is very good news for those of us interested in red spirals as an evolutionary stage!
If anyone is in the Kingston area there will be a public lecture at 8pm tomorrow night given by Prof. Sandy Faber. It’s on the Queen’s Campus in the Biosciences Building, Room 1101. I include the poster below. Sandy Faber was a student of Vera Rubin’s and gave a very nice review talk this morning about her early work on dark matter during this time. I encourage you to attend if you are able – I think it will be a very nice public astronomy talk.
She's an Astronomer: Vardha Nicola Bennert
Vardha Nicola Bennert by the ocean in Santa Barbara (a 5 minute walk from her office at UCSB), May 2009.
Dr. Vardha Nicola Bennert is a postdoctoral researcher (“postdoc”) in the Physics and Astronomy Department at the University of California (UC) in Santa Barbara. Originally from the Ruhr area in Germany, she completed her PhD in 2005 on the astrophysics of active galaxies at the Ruhr-University of Bochum. She then moved to the US for a first postdoc at UC in Riverside, before moving to Santa Barbara in 2008.
Dr. Bennert’s research interests focus on the central region of “active galaxies” (the black hole and the so-called narrow- and broad-line regions immediately around the black hole) and its relation to the host galaxy. She enjoys working in the stimulating research environment at UCSB and living in Santa Barbara – especially because the sun is always shining and the beach is so close! But she also misses her friends and family in Germany. In her free time, she loves to explore the outdoors of southern California, and is also on an inward journey, integrating meditation into her everyday life.
- How did you first hear about Galaxy Zoo?
By coincidence! I was at UC Riverside and had an upcoming observing run at the 3m Shane telescope at Lick observatory when Prof. Bill Keel contacted my supervisor, Prof. Gabriela Canalizo, asking whether we could get a spectrum of “Hanny’s Voorwerp”. I agreed, went observing, had several clear nights and was able to get the spectrum. I was immediately intrigued by the object as the spectrum looked very familiar to me – very much like the narrow-line regions of active galaxies that I studied intensively during my PhD thesis, except that there was no evidence of an active galactic nucleus in the center!
- What has been your main involvement in the Galaxy Zoo project?
I helped in the reduction, analysis, and interpretation of the spectroscopic data which were integrated in the discovery paper of the Voorwerp. Later, by another coincidence, the team was looking for someone with experience in reducing HST images, which I have. So I obtained, reduced and analyzed HST images of the “peas” discovered in the Galaxy Zoo project. This formed part of another paper in which I helped in the interpretation of the results.
- What do you like most about being involved in Galaxy Zoo?
It is great that so many citizen astronomers are involved, and that it has such a strong public outreach component. For me, public outreach is not only our duty as researchers who are basically funded through the tax payers’ money but something that I enjoy a lot. I love seeing how people get excited about astronomy and the research that I am doing.
- What do you think is the most interesting astronomical question Galaxy Zoo will help to solve?
Galaxy Zoo has proved its value in revealing rare and interesting objects like the Voorwerp, through inspection of images by eye, showing the great advantage of humans over robots! I think this, more than answering a particular question for which Galaxy Zoo was set up, will be the lasting legacy. These rare objects have the potential to provide us with new and surprising insights.
- How/when did you first get interested in Astronomy?
As a child, I loved looking at the stars, and was fascinated by the books by Prof. Stephen W. Hawking, although I did not understand much at the time… However, this did not turn me off from pursuing a scientific career. On the contrary, I always found it exciting to be at the edge of my understanding and learn new things all the time.
- What (if any) do you think are the main barriers to women’s involvement in Astronomy?
I do not like the very competitive way in which scientific results are promoted. Personally, I think that it must be difficult for women to have children while pursuing an astronomical career, since both tasks are quite time demanding. But of course, there are many women in astronomy who prove that it is possible.
- Do you have any particular role models in Astronomy?
My PhD advisor, Prof. Hartmut Schulz, had a strong influence on me. I always considered him to be one of those “old-fashioned” professors who not only know so much about astronomy, but who have a profound general education with the emphasis on thinking for one’s own. Prof. Schulz sadly died in August 2003. I remember him gratefully for having been my “Doktorvater” in the truest sense of the word.
Also, my current supervisor at UCSB, Prof. Tommaso Treu, is a constant inspiration – he is not only very smart and extremely effective, but he is also always joyful, full of energy, and helps his students to make the best out of their potential.
This post is part of the ongoing She’s an Astronomer series on the Galaxy Zoo Blog in support of the IYA2009 cornerstone project of the same name (She’s an Astronomer).
This is the second post of the series, last month we interviewed Hanny Van Arkel (Galaxy Zoo volunteer and finder of Hanny’s Voorwerp).
Next in the series: Alice Sheppard (forum moderator).
She's an Astronomer: Hanny van Arkel
Hanny’s interview in het Nederlands
Hanny van Arkel is a 25 year old teacher, who lives in the South East of the Netherlands with her German Shepherd, Janey. She plays guitar and at the moment she teaches music in a primary school in Heerlen, where she also works on science boxes (boxes of science experiments for kids) and is a general stand-in. Hanny discovered what is now known as “Hanny’s Voorwerp” while classifying galaxies on Galaxy Zoo, back in 2007. She writes about her adventures since then on www.hannysvoorwerp.com. (Picture Credit: H. van Arkel)
- How did you first hear about Galaxy Zoo?
I have a passion for music and play guitar myself. Brian May (Queen’s guitarist) is one of the people I admire for his music and for what he writes on his website, www.brianmay.com. When the project had just started, Brian wrote about it there, saying you could help scientists by sorting through these beautiful pictures. So that’s when I thought to check it out.
- What has been your main involvement in the Galaxy Zoo project?
That would be discovering “Hanny’s Voorwerp” and everything that happened ever since. I still classify galaxies as well, but mostly I ‘spread the word’ by talking to the (international) media, I give lectures about the Voorwerp and Galaxy Zoo and I participate in events, for example.
- What do you like most about being involved in Galaxy Zoo?
One of the things I still like is the fact that people without a scientific background can actually contribute to real scientific research here. And personally I get a lot back from it as well and then I’m not even talking about all the fun stuff I get to do. I’ve learned a lot about astronomy in general and the English language for that matter and I met some of my best friends through the Galaxy Zoo meet-ups.
- What do you think is the most interesting astronomical question Galaxy Zoo will help to solve?
Well, besides what the investigations of “Hanny’s Voorwerp” will bring, I’m also very curious as to what the “peas” exactly are, to just name two I’m involved in. But it’s a hard question actually, as there are so many things to learn from this project and it’s such a success… who knows what we’ll find out in the future?!
- How/when did you first get interested in Astronomy?
I’ve always been eager to learn and I liked all the subjects in school. I never had ‘astronomy’ as a subject though, but I do remember a little project about it in my primary school. However, I had always appreciated the night sky, even though I don’t have a telescope or anything. What really got me interested was Galaxy Zoo, back in the summer of 2007.
- What (if any) do you think are the main barriers to women’s involvement in Astronomy?
Are there? I mean, I know that only approximately a quarter of all professional astronomers are woman, but I can’t think of something that would’ve stopped me to be honest.
- Do you have any particular role models in Astronomy?
Yes, I’ve met a lot of people the past two years, who I admire. First of all, the members of the Galaxy Zoo Team. Besides coming up with this great idea and obviously working hard for it, they make sure the volunteers feel a part of it all. They take time to explain things in an understandable way, for instance. I also have respect for everything Pamela Gay does, she’s a very good example of a successful woman in astronomy. Furthermore I did a lecture together with Cees de Jager (website in Dutch) once, and it was great to see someone being so devoted to astronomy as he was. Patrick Moore, obviously. And Brian May, for ‘going back to school’ after all those years. And I recently worked with a few people from ASTRON (the Netherlands Institute for Radio Astronomy) and thought the way Joeri van Leeuwen taught kids about pulsars was very inspiring. To name just a few.
IYA 2009: She's an Astronomer
As most of you are aware, 2009 is the International Year of Astronomy, and all sorts of projects have been launched to promote astronomy. One of the IYA2009 Cornerstone projects is She’s an Astronomer and its aim is to address the issues around gender imbalance in astronomy (only roughly 1/4 of professional astronomers are women) by promoting gender equality and empowering women.
At Galaxy Zoo we have decided to participate in the She’s an Astronomer project. Throughout 2009 we will be posting to the Galaxy Zoo blog profiles and interviews of women who have been involved in the Galaxy Zoo project (both as volunteers and as scientists). We hope you will enjoy reading about the wide variety of women who have been and continue to be involved in the Galaxy Zoo project.
The first post – about Hanny van Arkel will follow shortly.
The European Week of Astronomy and Space Science
Last week (April 20th-23rd) the University of Hertfordshire in Hatfield hosted the European Week of Astronomy and Space Sciences which incorporated both the Royal Astronomical Society’s National Astronomy Meeting (NAM) and the Joint European and National Astronomy Meeting (JENAM) for 2009. Galaxy Zoo was reasonably well represented at the meeting with 3 past and present team members attending.
On Tuesday afternoon Daniel Thomas presented a talk entitled “Secular Evolution in Spiral Bulges”. This was about work based on a small sample of galaxies with morphological classifications (pre Galaxy Zoo) and explored the idea that secular evolution (ie. slow steady evolution not involving mergers etc) in the disks or spiral galaxies could be expected to drive gas into the spiral bulges thereby making spiral bulges form new stars and have younger stellar populations than elliptical galaxies (or “diskless bulges”). The study found no evidence for such disk driven evolution – but did find that both low mass ellipticals and spirals seem to have younger populations than higher mass ones. Daniel finished by talking about the prospects for Galaxy Zoo 2 to vastly increase the sample size (from 35 to a quarter of a million), so is obviously looking forward to having that data to hand to explore this issue further.
At Wednesday lunchtime, past Galaxy Zoo team member Kate Land was involved in the Careers Lunch, participating in a presentation by 3 former astronomy researchers who talked about their new jobs applying the skills they learned doing scientific research to researching trends and behaviour of financial markets. Kate talked about the pros and cons of her new job relative to being involved in astronomical research. These included some loss of autonomy, but more support, and shorter timescales for getting results. Otherwise the general theme from the discussion was how similar financial market modeling is to science research and how many of the skills developed by astronomical researchers are transferable into such jobs.
On Wednesday afternoon I presented my work on the trends of colour with inclination observed in spirals identified by the first phase of Galaxy Zoo. This reddening with inclination is expected if the disks of spirals have a significant amount of interstellar dust in them. It’s useful to know how much reddening there is so that we can reconstruct the real colours of the spiral galaxies (and find the true “red spirals”, not just those reddened by dust). Also the details of the curve of reddening with inclination in different SDSS filters can provide clues to the type and amount of dust in the spirals. You can read more about this work in my previous blog post about it. It’s all progressing well, and we plan to submit it for peer review very soon.
Karen Masters.
Galaxy Zoo at the British Astronomical Association
On Saturday I gave the after dinner talk at the British Astronomical Association (BAA) annual weekend in Winchester. At the BAA they call this talk the Alfred Curtis Memorial Lecture in memory of Alfred Curtis – a former BAA member who was instrumental in setting up the BAA annual weekend.
I’ll confess I didn’t know much about the BAA before this talk, and I came away extremely impressed at the level of knowledge and commitment about astronomy that I saw among its members. I was surprised to learn about how professional some of the observing facilities and programs of amateur astronomers are. Saturday night was very clear, so I was expecting the group would be anxious to head out for some star gazing, but actually many of them preferred to chat about the latest advances in astronomy at the bar with friends they don’t see too often, and leave their observing for nights they can really concentrate. They impressed me with information about their semi-automated observing of variable stars, or supernova which they then analyze on a computer, in much the same way that professional astronomers conduct observations
Many of the audience guessed in advance that I would be talking about Galaxy Zoo, despite my slightly cryptic title – “Finding Spirals – How to Look at a Million Galaxies”, and many of them told me afterwards about their involvement with Galaxy Zoo. We caught the end of the 100 hours of Astronomy drive (although after the 1 million classifications goal was met) so I advertised that in the talk, hoping to inspire some new Zooites.
The aim of my talk was to show all the interesting thing we can learn about galaxy formation and evolution from galaxy classifications. Rutherford famously said “All science is physics or stamp collecting”, my talk was in defense of the great physics you can do after you do some stamp collecting and sort out your album! I started by introducing the basic classifications of galaxies, and going back to the original 1926 paper by Edwin Hubble about galaxy classification. I then talked about the basic picture we have for galaxy formation and evolution in our expanding universe in light of the differences we observe between the two main classes of galaxies, such as spirals being mostly blue and solitary (or at least not in large clusters), and ellipticals being mostly red and in clusters or groups. I then talked about the digital revolution in astronomy and how we now have catalogues of millions of galaxies which astronomers cannot hope to visually classify themselves. Of course this is where I started talking about Galaxy Zoo with lots of stuff about how popular it is, and all the exciting discoveries that have so far come out of the first phase of Galaxy Zoo. I talked a little bit about my own work using Galaxy Zoo, looking at how the colours of the spirals vary with viewing angle. I finished by advertising Galaxy Zoo 2. I talked about some of the impressive statistics (like passing the 20 million clicks mark), and showed some of the examples of successful classifications. At the very end I showed a sneak peak of the Google Earth Tour of spiral galaxies which Ben Hoyle and myself made at Portsmouth. You can see this for yourself once you have classified at least 100 galaxies in Galaxy Zoo 2.
Karen.
Edit: a picture of BAA president, Roger Pickard and me deep in discussion about Galaxy Zoo.
Blue Sky and Red Spirals
This post is from Karen Masters at Portsmouth, who is working on red spirals….
When light travels through stuff it is scattered and absorbed. This is true of light passing through our atmosphere, and it is also true of light as it passes through galaxies. Light of different wavelengths is affected by this scattering and absorption in different ways. Bluer (or shorter wavelength) light is easier to scatter. The sky is blue on a cloudless day because the bluer light from the Sun is scattered out of the line of sight. This light “bounces around” off atoms and molecules in our atmosphere and eventually reaches our eye from some random direction – making the sky look blue. Obviously the light from the Sun itself appears slightly reddened by the same effect since the blue light is preferentially removed. At sunset or sunrise, when the Sun is close to the horizon the light from the Sun has to take a longer path through the atmosphere to get to us. More scattering takes place and the Sun appears redder than normal and makes a beautiful sight to see.
In spiral galaxies, the length of the path the light takes through the galaxy before it gets out and heads towards us depends on our viewing angle. When we see a spiral galaxy face-on the light has the shortest possible path out of the galaxy. By contrast, in an edge-on galaxy, the light must travel through most of the disk before getting out. We expect then that if scattering is important, edge-on galaxies will appear to be redder than face-on galaxies – for similar reasons that sunsets are red. The big question here though is “is scattering important”. Put another way we want to ask “are the disks of spiral galaxies transparent?”. We enjoy a fairly clear view of the extragalactic sky out of our spiral galaxy (the Milky Way), which suggested to early researchers than spiral galaxies probably were transparent. However it is also clear that there is a lot of “extinction due to dust” (our Astronomers terminology for the effect of scattering and absorption of light by particles in the inter-stellar medium) when we look towards the Galactic centre.
So what’s the problem of just looking at a bunch of spiral galaxies and seeing if they get redder as they get edge-on? Well nothing… except that you need to know you’re definitely looking at spirals, and you need to figure out how to measure how edge-on the spirals are. This of course is where Galaxy Zoo helps out so much. Thanks to you we now have an enormous number of visually classified unquestionably spiral galaxies. You even picked out the edge-on ones for us. We can also use the “axial ratios” (the ratio of the maximum dimension to the minimum dimension) of the galaxies from Sloan, which (with some assumptions about how thin the average galaxy is when it’s totally edge-on) gives an estimate of the exact angle of the galaxy’s orientation to us.
And what we’re finding is that spirals definitely get redder as they get more edge-on. So extinction due to dust is clearly important. Because Sloan measures the galaxies in 5 different wavelengths, we can make 4 Sloan colours (in Astronomy the colour is just the difference in the brightness in two different bands) and look at the relative amount of extinction with wavelength which provides information on the source of the scattering and absorption. We can also go to other surveys (for example UKIDSS which measures near-infra red light) to extend this further for some of the galaxies.
Extinction seems to be quite a hot topic lately with Sloan data, but what we have which other researchers don’t is the Galaxy Zoo classifications. They have to use other estimates of if the galaxy is a spiral or not, such as how concentrated the light is, or the exact details of the light profile. Neither is as simple or as reliable as having a human just look at the galaxy. Measuring the amount of extinction is important because it’s been largely neglected in studies using Sloan data up until now. The physical parameters of a galaxy ought not to depend on our viewing angle, but when researchers use colours and luminosities to estimate the star formation history or stellar mass of a spiral galaxy the answer will depend on viewing angle if extinction due to dust is not corrected for. More importantly, elliptical galaxies do not suffer from this effect, so if you compare the mean properties of ellipticals and spirals your answer will be biased by the effect of dust.
So most red spirals seem to be edge-on dusty star forming galaxies which would be normal blue spirals if seen face-on…. but this can’t explain all red spirals. We can still see a significant population of red face-on spirals, and by measuring the average amount of reddening we will even be able to pick out the edge-on spirals which would still be red if seen face-on.
I moved to Portsmouth in October and I was delighted to start working with the Galaxy Zoo team and data. I knew about the project (and even classified a handful of galaxies) before I moved here. I’m currently working on a short paper describing what I’ve told you about here and hope to have it submitted early in the New Year.
Merry Christmas!
Some example images:
A blue face-on spiral galaxy.
A red face-on spiral galaxy.
A red edge-on spiral galaxy.
Galaxy Zoo 