Interview with Antonio La Marca

PhD Candidate at University of Groningen/SRON Netherlands, Institute for Space research

 

What is your current role within the ESA Euclid mission?

I joined the Euclid Consortium in 2021, at the beginning of my PhD, and I am a member of the science working group, focusing on galaxy evolution and active galactic nuclei (AGN). Within this working group I mostly focus on morphology - how we classify the galaxies visually by studying their appearance and shapes.
While the general focus of the working group is on super massive black holes and AGN, I have recently been appointed to be co-leader of the multi wavelength team within this working group. This is the team that will provide data sets and multi wavelength information that are coming from other facilities and telescopes ancillary to Euclid. This information is needed to better study galaxy properties.
Additionally, I lead a paper which uses Euclid Q1 data and studies galaxy mergers; mergers happen when two or more galaxies collide and interact to form a new and more massive galaxy; we also study their connection to what triggers the AGN phase.
In the future, I will also continue to work with Euclid data, as I will start a research fellowship at ESA in the fall of 2025. Here I will be able to expand my research more as we receive more data from Euclid. For the Q1 data release, we were limited to an area of about sixty square degrees, which will become much wider with time, and we will then be able to take more aspects of the galaxies lives into account. For example, we will be able to trace how the environment influences the galaxies, and how in turn these galaxies influence the activity of super massive black holes. In general, I will try to explore the evolution of galaxies from redshift ~2 to nowadays galaxies, so roughly the last 10 billion years of cosmic history, to understand how galaxies formed in much greater detail.

Have there been any unexpected findings or surprises in the ESA Euclid mission so far?

I will not say surprises per se, but for me a surprise was that we met the expectations, in the sense that what we were expecting based on the early release observations from the James Webb Space Telescope (JWST), were actually also found with Euclid, but with larger statistical power. To give a concrete example, in the past I studied galaxy mergers, using data from JWST and the Hubble Space Telescope; these experiments allowed us to find a few thousands of galaxy mergers. However, using Euclid data, we found 100,000 galaxy mergers for our Q1 data release paper, just with the Q1 data. The fact that we were able to meet the expectations and revolutionise this field - entering a statistical regime where we can finally do robust analyses and draw robust conclusions because of the large amount of data - is amazing. We are no longer studying individual galaxies with low statistical power; we have moved into a new regime. We also confirmed what we already observed with the JWST: galaxies have clear structures like spiral arms and discs, that are already in place at early times in the universe, which is something that is now challenging our understanding of galaxy evolution.

What part of the Q1 data release and your own research are you most excited about?

Since I was young, I have really loved looking at astronomical images - I am fascinated by galaxies, their shapes, and their visual appearance, and it excites me a lot, trying to connect these large structures to their physics. Trying to understand how the way they appear is connected with their evolution and with how they function, is what really excites me in my own work.
With Euclid, what is impressive is again the statistical power. The fact that we can now study galaxy evolution and get better knowledge, with smaller uncertainties and much more accuracy in what we are doing, is amazing. This will guide the next generation of models and simulations, helping us better understand how galaxies like our own Milky Way formed and evolved over time. Being able to do these statistical analyses is really important and exciting.

Based on the knowledge you have now from the Q1 data release, what are your main expectations from Euclid in the future?

The Euclid Q1 data release was relatively small for the cosmological studies, and it helped us to study galaxy evolution, to gain more insights in galaxy formation evolution. With the next data release, we will focus on cosmology, as the core idea of Euclid is to map the matter distribution of the universe. Given the fact that we were able to meet the expectations on galaxy evolution, I expect that we will also be able to meet the expectation on the cosmological side. And I am really looking forward to the first detailed map of the universe.

Do you have any advice for people who would like to follow a similar career path or to use Euclid data?

For what concerns Euclid data, I will say that ESA is doing a great job in making the data accessible. Everyone can go to the ESA Euclid archive and to ESA Datalabs, and access public data, and this is what I would suggest doing if you want to start using Euclid data. Explore ESA Datalabs and start playing with the data online. Furthermore, I would highly recommend asking questions to people who are already in the Euclid Consortium. All of us are really happy to help, and because the data volume is so big, we always need extra manpower. We are always happy to share tips, and all of us have gone through issues which we had to solve, and we will gladly assist others with this as well.
If someone would like to follow a similar career path, I will say that first of all, you really need to have a big passion for this job. Keep being curious, and do not be scared to ask questions. I would advise you to ask many, many questions. Often, when you are a young researcher, you are afraid that your question to a senior professor at the university will be a stupid question, and you therefore decide not to ask any question. I think it is important to overcome this fear, as asking questions is really the only way we can learn, and this is also very important to keep your passion alive.

 

 

For further details on Antonio La Marca's work on galaxy mergers and their connection to Active Galactic Nuclei, please refer to the following scientific paper submitted to the arXiv:

For more information about the Euclid Q1 release, visit the ESA press release: