Interview with Clotilde Laigle

Assistant astronomer at Institut d'Astrophysique de Paris

 

What is your current role within the ESA Euclid mission?

"First, I work within the Science Ground Segment. I am in the team that works on data processing of the images from the camera observing the visible part of the spectrum called the VISible instrument (VIS). We are a team of engineers and researchers, and I participate in the validation of the pipeline. That takes up about 30% of my time. My second involvement is on the scientific analysis of Euclid data, where I am specifically interested in aspects related to galaxy formation."

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

"At the data level - yes of course.
Speaking from my work on the VIS team, once the satellite was launched, we discovered some unexpected things on the images that were not foreseen on the pipeline side, or on the calibration side, let's say. But these were some issues that we were able to solve. On the science side, I think the data is beautiful - we see that we will be able to do beautiful science, but I don't think we have found yet some really unexpected things in the Universe with Q1 data."

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

"Well, I think it is great to see that we are able to do a fine analysis of galaxy morphologies and relate them with their cosmological environment. I work on galaxy formation within the cosmic web, so I need a large volume of data to analyse the large-scale distribution of galaxies. Euclid offers that, which is great, and even though the Q1 data is very small compared to the full Euclid area, it already allows for such analysis. Being able to relate the cosmic web with the detailed morphological analysis of galaxies is amazing - that is really exciting."

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

"In the future, I think Euclid will offer us more statistical power. In addition, because it will cover such a large volume, it will allow us to find rare objects. For example, we can probe the most massive galaxies, which are rare: you need a large survey to find them, and especially to gather a statistically significant sample. Essentially, with Euclid we will be able to look at the tails of the distribution in terms of galaxy properties. That is very interesting because in general these objects at the tails of the distribution are the ones that challenge our models. From a galaxy formation perspective, that is what I expect."

Do you have any advice for people who would like to use Euclid data?

"To people who want to pursue a career in research, it is important not to censor yourself - just have confidence in your ideas and what you believe is worth investigating. Even if it is different from what others do - taking different viewpoints is how we can gain a better understanding of the Universe. Regarding the use of Euclid Q1 data, we should be careful because this is the first time we are releasing data. The pipeline team did their best with this data, but some aspects of the pipeline still need improvement. As with any new dataset, researchers working on Q1 data have to be careful and do a lot of checks to make sure everything is okay."

 

 

For further details on Clotilde Laigle's work on the galaxy shapes and alignments in the cosmic web, please refer to the following scientific paper published in arXiv:

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

 

 

Photo credit: Marie Dumain (https://www.mariedumain.com/)