I am interested in understanding how galaxy clusters form and evolve.
Currently, my research focuses on the evolution of galaxies, intracluster light and the hot gas in clusters and protoclusters. I have a broad range of interests, including AGN, large-scale structure, and cosmology.
In Werner et al. (2026), we used the TNG-Cluster and Manhattan Suite simulations to investigate the formation and assembly of intracluster light in protoclusters.
We found that there is a considerable amount of ICL that was formed in the infall region of protoclusters and then later migrated to the cluster core.
The purple dots are general protocluster stellar particles and the yellow stars are ICL stellar particles, the circles represent R200c and 3R200c. We can clearly see that some of these stars are being formed outside R200c and migrate later to the protocluster core. We predict that there is a reasonable amount of ICL in the infall region of protoclusters and that they were mostly stripped from massive galaxies when compared to the protocluster mass function.
2024-2026
2019-2021
In this image from Wilson+08, we can see a high-z galaxy cluster and its red galaxies. Why should we look at them? We must look at high-zs to understand how these objects formed and evolved. I am interested in knowing more about these monsters of the cosmos and their galaxies! In Werner et al. (2021), we used the GOGREEN and GCLASS data to investigate the infall region of galaxy clusters at z~1. We found that the galaxies in the infall region are very different from field and cluster galaxies. We also found that most galaxies quenched before entering the main cluster halo, and satellite quenching was not important at z~1. This effect is stronger for more massive galaxies; most quench before arriving in the cluster. The main physical mechanism is unclear, and it can be due to preprocessing in groups, AGN or other mechanisms. We discuss it more in the paper.
Free-floating stars in the core of galaxy proto-clusters
2021-2023
Free-floating stars within galaxy clusters are thought to result from gravitational tides and galaxy interactions that rip stars away from their parent galaxies. Within the cosmological paradigm of hierarchical structure formation, such interactions accumulate over time which suggests that the amount of intracluster stars should be negligible in young proto-clusters and grow to around a quarter of the stellar mass in the oldest, most mature clusters. In contrast to these theoretical expectations, we report on the detection of copious intracluster stars within two proto-clusters at a redshift of 2. The distribution of stars in these protoclusters is similarly extended as in nearby mature clusters. This suggests that intracluster stars are a generic feature of massive dark matter halos, regardless of when these halos are observed. This paper was recently accepted by MNRAS (Werner et al. 2023).
S-PLUS galaxy clusters and groups catalogue with PzWav
2017-2022
We used the S-PLUS survey data (Mendes de Oliveira et al. 2019) and the PzWav technique to build a galaxy cluster catalogue (Werner et al. 2022). The S-PLUS data take advantage of 12 optical filters, which return precise photometric redshift estimates. Using simulations, we show that the photo-z precision influences cluster detections. We also used simulations to find the best parameters and check the purity and completeness levels we could reach. More information about the catalogue can be found in Werner et al. (2022). The catalogue is available on GitHub.
Using simulations, we can visualise the detections of clusters and groups in different redshifts for different mass ranges. In the video, we show a small area of the sky, and it is possible to see the clusters appearing in the smoothed images. More massive clusters are more prominent in the video. We added the log of the mass in solar masses, the redshift of each cluster, and the redshift of the slice in the top right.
If you want to know more about my work, you can go to the CV tab or to my ADS library or my Google Scholar profile. There you will find more detailed information.