Dr Becky Smethurst
All About Space talks to the astrophysicist and YouTube sensation about life, the universe and everything
How would you describe your research to somebody outside your field?
The job of a researcher is to answer the questions that no one knows the answers to. To do that you obviously have to think of the question first. My specific research is all to do with the connection between galaxies and the supermassive black holes that we find at the centre of every single one. Something that massive has a big effect on everything around it, and my job is to work out whether feeding this black hole has a negative impact on the galaxy.
I notice you use data to infer quenching histories. Can anything be done to improve these inferences in the future?
What I’m trying to do is model how many stars a galaxy is forming based on how much light I’m getting from that galaxy, so that’s the inference bit. You observe one thing, but you want to know another thing. We can use different data to improve this inference. Instead of just looking at how much light there is, we look for what’s called emission-specific wavelengths due to elements that are there.
Hydrogen is fuel for star formation, so if there’s lots of it you know you’re forming lots of stars. We can use those kinds of fingerprints that are much more precise to improve our inference, but it also comes with improving computational models and statistical methods. Research that’s going on right now in computer science and maths will eventually improve that kind of inference as well.
‘Understanding the physical processes that have shaped our universe is the fundamental goal of astrophysics’ – so begins your PhD thesis. How close are we to achieving this goal?
I think that there is so much more that we don’t know than we do know, and I think it would be arrogant of us to assume that we’re even close to figuring out the properties of the entire universe. We are so small, and the universe is so big. It’s fantastic what we’ve done so far. The fact that we can measure black hole masses and figure out how massive galaxies are and how they’ve evolved is incredible, but I don’t think we’re anywhere near to being done. And I don’t think any astrophysicist would ever want to be – we’d be out of a job, and knowing everything is boring.
