Kasper Elm Heintz

Project title

Charting Cosmic Dawn: From primordial matter to the formation of stars in galaxies

What is your project about?

The Universe is teeming with galaxies – vast, cosmic ecosystems composed of gas, dust, and billions of stars. Galaxies are of vital importance to modern astrophysics: they trace the structure of the Universe and serve as the main sites for star formation and black hole growth. Despite their central role in our cosmological understanding, we still know very little about when and how the first stars and galaxies actually formed. With the PRIMORDIAL project, I will shed new light on this process by carrying out the first direct measurements of cold, neutral gas – the building blocks of stars and galaxies – in and around some of the first galaxies in the history of the Universe, using some of the largest telescopes on Earth and in space.

How did you become interested in your particular field of research?

I have always been curious about physics – and especially space – and from an early age I was fascinated by some of the most fundamental questions such as: Where do we come from? How did we go from nothing to the cosmos we see around us today? These are questions that we are now actually in a position to answer. Conducting research in astrophysics allows me to pursue this curiosity while also challenging and expressing my creativity. At the same time, the field is rapidly progressing, and I follow with great interest the technological and scientific advances currently driving it forward.

What are the scientific challenges and perspectives in your project?

One of the greatest limitations in astrophysics is that we will never be able to see what the Universe looks like “right now,” due to the fast but finite speed of light. Yet this is also an advantage: the farther we look, the further back in time we observe. With today’s most powerful telescopes, it is now possible to look almost all the way back to the beginning of the Universe and the formation of the first structures – the main goal of this project. The two main challenges are that the light from the first stars and galaxies, originally emitted in the ultraviolet, is now redshifted to the infrared by the time it reaches us. In addition, we must develop new methods to observe the first cold, primordial atoms – which do not emit light themselves – in order to determine how they collect and form the raw material needed to build the first stars and galaxies.

What is your estimate of the impact, which your project may have to society in the long term?

One of the biggest and perhaps most fundamental questions humanity has asked itself throughout history is: “Where do we come from?” This is now a question we are finally able to begin answering through basic research in astrophysics – research that will undoubtedly influence and leave a lasting imprint on our general culture and shared knowledge. This type of science also drives major technological and scientific progress as we push the boundaries of what is possible in order to look further back in cosmic time than ever before. At the same time, this research can help inspire wonder and curiosity about the Universe, especially among children and young people, and foster interest in science among the next generation of researchers.

Which impact do you expect the Sapere Aude programme will have on your career as a researcher?

Although we have studied galaxies for nearly a century – and are now beginning to detect starlight from the earliest galaxies shortly after the Big Bang – we still know very little about how the first stars and galaxies were actually formed. This Sapere Aude project allows me to develop a new method for observing these earliest galaxies, which will enable us to map and measure the cold, primordial gas in and around them, and thereby study their formation directly. This research will fundamentally transform the field and provide us with a unique opportunity to study star and galaxy formation in the early Universe. It will place me at the forefront of the field and enable me to optimally prepare for observations with next-generation telescopes, such as the Extremely Large Telescope, currently under construction in Chile.

Background and personal life

I grew up in Gladsaxe, just outside Copenhagen, where I attended primary school and high school. I later studied physics at the University of Copenhagen, specializing in astrophysics. After graduating, I moved with my family to Iceland, where I worked as a PhD student and later as a postdoctoral researcher. Three years ago, I returned to Denmark and the Niels Bohr Institute on a Carlsberg Reintegration Fellowship, where I now work as an assistant professor. I am excited to build up my own research group and proud to be back in Denmark, contributing to shaping our future role on both the national and international research stage. In my spare time, I enjoy outdoor activities and spending time with my wonderful wife and our three young boys.