Dr O. Ivy Wong
-Physical processes that govern how galaxies form stars, grow supermassive black holes and evolve
-Multiwavelength observational astronomy
-Large radio continuum and atomic Hydrogen (HI) surveys
-Radio Galaxy Zoo (http://radio.galaxyzoo.org)
– Machine learning applications for future radio astronomy surveys
THE INTERVIEW below WAS CONDUCTED IN 2014
What are you working on now?
In general, my research revolves around studying the physical processes which trigger galaxies to start and to stop forming stars.
My current projects are:
- A pilot project that investigates the gas content of a sample of galaxies which will soon stop forming stars very quickly.
- Working with ICRAR colleague Professor Gerhardt Meurer on the SUNGG project, which studies the detailed processes that govern star formation in nearby galaxies.
- I’m also working on Australian SKA Pathfinder (ASKAP) science commissioning for the Wallaby (next-generation all-sky neutral hydrogen survey using ASKAP) and working with the original HIPASS team to put together HIPASS version 2.0.
What got you into astronomy?
I started as a physics undergraduate at the University of Melbourne but was quite unsure of the specific area of specialization so I had applied and got a vacation scholarship to work with the Astrophysics group there at the end of my 2nd year to check what research in Astrophysics was all about. The first sneaky thing they did was to bring me up to the Parkes radio telescope to observe for HIPASS over the Christmas/NY period between 1999-2000. I was hooked from then on and as the cliché goes, the rest is history.
Why is your work important for ICRAR?
My research originated in radio and HI surveys but has since evolved to multiwavelength (X-ray, UV, optical and IR) observations of the local Universe. Being at ICRAR makes a lot of sense because in addition to my knowledge in radio astronomy, my understanding of observations at other wavelengths provides valuable context and is complementary to the area of star formation and galaxy evolution. At ICRAR-UWA, my work is very relevant and fits in very well with some of the other multiwavelength studies of galaxy evolution through much larger surveys as well as theoretical simulations.
Why did you join ICRAR?
The next big discoveries will come from radio astronomy. Working at ICRAR puts me “closer-to-the-action” with the ramp-up of the next- generation radio & HI surveys such as Wallaby, EMU & DINGO (which all use the WA-based ASKAP telescope).
Where were you before you came to work for ICRAR?
I was at CSIRO Astronomy & Space Science (Marsfield, NSW) before I moved over to ICRAR-UWA.
What’s your favourite part of your work?
The science. Thinking about it, reading about it, doing it, writing about it, talking about it, arguing about it, being distracted by it!
What do you think is the most exciting thing about astronomy today?
That the rate of scientific output is much quicker than it ever was before. Not only are we reading 50-100 abstracts on the pre-print server (arXiv.org) daily, we now get the very latest discoveries via Twitter feeds (eg. The big X-ray flash from M31 this month).
So on the one-hand, this increase in information may be mind-boggling, and on the other hand, it has never been easier to collaborate with colleagues and access data from half a world away. It is very exciting to think that we are discovering more of the Universe faster than ever before.
You’re part of an online astronomy project known as Radio Galaxy Zoo. Could you tell us what it is and how you got involved with the project?
The Universe as seen by large radio surveys is very different from the ones seen in the traditional optical images of the sky that we all know when we look up at the sky. In addition to seeing star-forming galaxies, the radio maps also show large radio jets/plumes emanating from the central supermassive black holes of large galaxies. Because these jets come in all shapes and strengths, they do not always overlap with the host galaxy where it originated. So, the main purpose of Radio Galaxy Zoo (RGZ) is to ask our citizen scientists to help us identify the host galaxies of over 170,000 radio sources.
Beyond identifying the host galaxies, people also have the option to classify the radio morphology/shape of the radio waves. We also provide them with some tools to discuss a particular source as well as links of the same field of view in other wavelengths to determine the type of galaxy and environment that these radio sources are a part of.
Although a relatively simple task, typical computer algorithms still fail to match up ~10% of the sources. This translates to 7 million sources if we expect 70 million sources from EMU (the next-generation radio survey using ASKAP)! So the hope is that the current version of RGZ will form the basis for EMU’s source identification as well as the training set for the development of intelligent automated matching algorithms.
I was and still am a part of the original Galaxy Zoo science team (the only Australian on that team) because this project was started by one of my good friends, Kevin Schawinski, when he was doing his PhD at Oxford. Naturally I got roped in and started studying a sample of galaxies that suddenly stopped forming stars.
While working at CSIRO, another postdoc there (Julie Banfield) wanted to start RGZ and I joined the team initially as a GZ advisor. When Julie went on maternity leave, I took over the project. Now that Julie has returned from maternity leave, we lead the project together.
Were you surprised at the level of interest and the amount of contributions you were receiving from the public in helping provide classifications?
Personally, having experienced Galaxy Zoo, I was not surprised at the level of interest in the project because there are many people around the world who are genuinely interested in science/astronomy and would like nothing more than to help us. What was surprising really is the level of commitment of our super citizen scientists. These are the citizen scientists who will trawl through various databases and spectra and figure out exactly what other forms of emission these host galaxies are also emitting. By doing so, we made a discovery of a giant Wide-Angled-Tail (WAT) source within a few days of our launch. The maps that we used were published in 1995. Much to the surprise of the science team, this WAT stayed unnoticed until December 2013 when a few of our super citizen scientists reported that the source that they were looking at was actually part of a much larger structure. The discovery paper is being written as we speak!
What exciting developments can we see coming from Radio Galaxy Zoo in the future?
One of the biggest advantages of a citizen science project such as RGZ is the fact that we are applying the best parallel processors to the problem: the human eye-brain combination. An automated algorithm will find you everything you tell it to look for, but a human will point out and ask about the things that you never told them about before.
Not only do we have an advantage with discovering new objects, the completion of the current RGZ will yield the largest catalogue of radio source identifications.