Canadian astronomer Dr. Jayanne English will talk about new research on the magnetic fields of spiral galaxies at the April 9th meeting of the Ottawa Centre of the RASC (Royal Astronomical Society of Canada). This Zoom meeting is free and open to the public.
Dr. English is a member of an international consortium, led by Dr. Judith Irwin of Queen’s University, that is studying spiral galaxies.
She’s has been a columnist on CBC’s “Quirks and Quarks”. She was the Coordinator of NASA’s Hubble Heritage Project. She’s a professor of Physics and Astronomy at the University of Manitoba. English has a Ph.D in Astronomy and Astrophysics, and a Diploma from the Ontario College of Art and Design University. She uses her art background to enhance her scientific work.
We caught up with Dr. English ahead of their talk on April 9th. This interview has been edited for length.
Apt613: You’ve published an image of spiral galaxy NGC 5775. It’s not a run of the mill astronomy photograph. What are we looking at here?
Dr. Jayanne English: What we’re looking at here is a tracing of the magnetic field lines that are coming out of the spiral disc galaxy NGC 5775.
A spiral galaxy—we can see them at different orientations on the sky. This one is seen edge-on to our line of sight, which means that we can see anything away from the disc. We can see any luminosity and brightness and emission from gas. Everything isn’t exactly in the plane of the disc, but there are things sticking out of galaxies.
Now with a radio telescope, we can probe the magnetic field structure that’s sticking out of the galaxy. This was not explored in detail until Canadians contributed to the new extension to the Very Large Array (VLA) in New Mexico.
Not only is there emission that we see in radio wavelengths. The energies of the emission are so low that we see them with radio telescopes. We knew there was this emission. But now we can actually see that there are magnetic fields sticking out of the galaxies that have a structure that looks almost like an X shaped structure and extend really far.
What we’re looking at is a representation of those magnetic field lines. The representation itself isn’t an illustration. It isn’t a drawing. It’s made out of the data that is produced by the magnetic field lines.
A team like this doesn’t work on just one image. What is the bigger picture the team is trying to explore?
The team isn’t making images. The team is the scientific consortium. CHANG-ES (Continuum Halos in Nearby Galaxies: An EVLA Survey) is a scientific consortium doing all sorts of different studies of edge-on galaxies.
No astronomy projects are done by one person. You have someone like me embedded in a team. I’m a scientist. I look at the data and go, “I want to make an image.”
Something we learned from the Hubble Heritage Project is that you want to make the scientists who collected the data appreciate your image. They might not like it at first, but they might begin to understand it and appreciate it later.
I’m always interacting with the team. I’m always giving them a few different options for how to represent the image. I am making the image in conjunction with my team members.
There’s another thing that’s different about this image. Most astronomy pictures are centred on the object. But you don’t do that in this image. It’s not centred. Please explain your artistic choice for this image.
You’ve looked at my portfolio website. You’ll notice that none of my images are dead center.
If you put something dead centre, if you stare at it for some time, it’s going to look totally static. Your eye-brain system’s going to go. “It looks like a bullseye. I’ve seen bullseyes before. Been there, done that. I don’t have to look at this picture.” So what does that mean? It’s not engaging. They’re not going to look at it.
If for some reason you then stare at the image for some time, it’s going to look like it’s falling down the page. So what you do is you put it higher up. It’s dynamic.
I have an art background. I know about composition and I know about colour and I tried to train people to use the techniques from visual art and design in order to make an engaging image that the person will want to look at for some time. I want it to be based on how humans perceive. So it’s perceptually based techniques instead of culturally based.
You’re going to present at the April 9th Zoom meeting of the Ottawa RASC. You’re going to talk about more than you have here. Can you give our readers a teaser of why they should attend the Zoom meeting to learn more?
When we do the journalism and the articles we ask, what are people interested in? We direct it at the audience and the audience will always be saying, “I like black holes or aliens or something.” That isn’t what the astronomer is interested in. That’s not the frontier of astronomical research.
The occasional person, after we discover something and we tell them, they say, “Why didn’t you tell us this before?”
So I want to tell people what the astronomer is really keen about.
I want people to come and find out about radio astronomy, because they’re so used to looking at pretty pictures in the optical energy regime, which goes with our eyes. Really that part of the electromagnetic spectrum is very small. Our frontiers are in other parts of the electromagnetic spectrum.
Dr. Jayanne English will present during the next meeting of the Ottawa Centre of the RASC on Friday, April 9th at 7:30PM (EDT). The meeting is open to the public via Zoom. Admission to the meeting is free, but attendees must register for this meeting in advance.