Meet Renske Smit, latest researcher to join the Astrophysics Research Institute

Dr Renske Smit, currently a Newton-Kavli fellow at the University of Cambridge, will be joining the Astrophysics Research Institute (ARI) from October as an STFC Ernest Rutherford Fellow. We caught up with her to find out more about her area of interest and achievements in astronomy and her plans for her time at LJMU.

Renske will be joining ARI via the Rutherford Fellowship, a prestigious five-year scheme designed to enable top early career researchers to establish an independent research programme. She is planning to start a new research group while at LJMU to study the very early Universe: “I’m hoping to enthuse graduate and undergraduate students to work with me on studying this interesting period of our cosmic history. There are many researchers at the ARI – studying stars, stellar clusters or doing computer simulations of galaxies – that I want to work with to find synergies with my own work on distant galaxies.”

Renske studies our cosmic origins using the world’s largest telescopes to try to understand how the very first stars and galaxies were formed. She discovered her passion for astronomy in her home country, the Netherlands, while studying at Leiden University. She then moved to the UK, first as a research associate at Durham University and then as a Rubicon Fellow at the University of Cambridge. In 2017 she was awarded a Newton-Kavli Research Fellowship by the Kavli Institute for Cosmology at the University of Cambridge.

Last year, Renske received the MERAC prize for the best thesis in observational astrophysics by the European Astronomical Society. She was recognised for her work using both the Hubble and the Spitzer telescopes to design a new method for finding some of the most distant galaxies. These new galaxies turned out to be ideal targets to study with ground-based telescopes and led to new records for the most distant objects ever found, as well as new results she published in Nature. Renske was invited to give a plenary lecture at the Echo Arena in Liverpool for the prize ceremony during the European Week of Astronomy and Space Science, which ARI hosted.

Why did you choose to study astrophysics?

"In high school I really liked physics, but I was unsure about studying it at uni. I had this negative preconception of physicists working in dark basement laboratories with lasers and I didn't think it could be for me. Like many people, I hadn't ever realised it's possible to study astronomy too, until I signed up for an open day at my local university. I was immediately excited about the idea of using physics to study the Universe, though I still had my doubts about what profession I would end up in – I didn't for a moment think of a career in academia! However, I was pleased to find that astrophysics graduates ended up in a wide range of jobs, from banking and finance to data science or medical imaging. I figured that studying astrophysics would make a solid basis to start my professional life, keeping my options open, while learning about the secrets of the cosmos along the way. It wasn't until my final year of my undergraduate studies that I had the chance for hands-on research and I just fell in love with it! That was the first time I started planning for a career as a scientist and professional astronomer. If you would tell my 10-year old self what my career looks like now, I would never believe you. I had to find this path one step at a time."

Atacama Large Millimetre Array (ALMA), which is the largest millimetre/sub-millimetre telescope in the world, located in the Atacama Desert in Chile. Renske used the telescope to study the rotation of gas in distant galaxies.

Can you talk about your role in the discovery of the most distant galaxy known to science?

“Between 2015 and 2016 I was part of the science team that broke the record for the most distant galaxy known three (!) times in a row – the last record was set in March 2016 and still stands. Because the speed of light is fast but still finite, we know that the deeper we look into the Universe, the further we look back in time. These record galaxies are found roughly 13.4 billion years in the past – just 400 million years after the Big Bang! In order to find galaxies that are so far away, I developed a technique using a combination of the Hubble and Spitzer Space Telescopes to discover new galaxies – this is part of the work for which I was awarded the MERAC prize. After identifying the best galaxies candidates using my method, our team managed to make high-precision distance measurements with follow-up studies using ground-based telescopes.”

What will you be working on while at ARI?

“The most exciting advancements in my field are currently made by using sub-millimetre telescopes to obtain a new view of the galaxies in the early Universe that have been discovered in the last decade with the Hubble Space Telescope. While Hubble has optical and near-infrared cameras to observe young, hot stars in distant galaxies, we can use sub-millimetre telescopes to see the cool gas and dust in between the stars. This gas and dust is thought to be the fuel that galaxies use to grow and form new stars. I am leading four new research programmes as Principal Investigator, using the Atacama Large Millimetre Array (ALMA), the largest sub-millimetre telescope in the world. I will be studying the chemical composition and the detailed kinematics of some of the most distant galaxies known.

“I will also be preparing new observations with the long-anticipated successor to Hubble: the James Webb Space Telescope. Its launch is planned for March 2021 and the strategic planning for the science that can be done with this telescope is already years in the pipeline, but will need further refinement as the launch date comes close.”

Rendering of the James Webb Space Telescope. Renske will be part of a survey team for the telescope.

As one of only a handful of UK-based astronomers in the core survey teams of the James Webb Space Telescope, can you tell us a bit more about your involvement with the most ambitious and expensive piece of astronomical instrumentation ever built?

“To study the first generations of galaxies, we look at the light that was emitted more than 13 billion years ago and that has been travelling through the ever-expanding Universe for all that time. During its journey through the cosmos, this light gets ‘stretched’ due to the expansion of space, which changes its wavelength, and therefore the colour, making them redder. This reddening of light means that the most distant galaxies can only be seen in infrared part of electromagnetic spectrum. Because Hubble was never designed to be an infrared telescope, it has reached its limits when it comes to finding the first stars and galaxies. The James Webb Space Telescope has been designed to see beyond the limits of Hubble and will be able to see the very first starlight that once illuminated the cosmos. The European Space Agency has built one of the instruments on-board ‘Webb’ and our European team from six different countries has teamed up with scientists working on the complementary NASA instruments to bring about the largest survey undertaken during the lifetime of this telescope, the JWST Advanced Deep Extragalactic Survey (JADES). The survey is designed not only to find galaxies more distant than have ever been seen, but also to study their physical properties. We will identify the elements that were once created by the Big Bang and the particles that were created in the supernova explosions when the first stars died. We will use this to identify the most primordial objects that have once formed and track their evolution in time as they grow up to be galaxies much like our own Milky Way.”

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