Examinando por Autor "Lima-Dias, Ciria"

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    CHANCES, the Chilean Cluster Galaxy Evolution Survey: Selection and initial characterisation of clusters and superclusters
    (EDP Sciences, 0025) Sifón, Cristóbal; Finoguenov, Alexis; Haines, Christopher P; Jaffé, Yara; Amrutha B.M.; Demarco, Ricardo; Lima E.V.R; Lima-Dias, Ciria; Méndez-Hernández, Hugo; Merluzzi, Paola; Monachesi, Antonela; Teixeira, Gabriel S. M.
    CHANCES, the CHileAN Cluster galaxy Evolution Survey, will study the evolution of galaxies in and around 100 massive galaxy clusters from the local Universe out to z = 0.45, and two superclusters at z ∼ 0.05 that contain roughly 25 Abell clusters each. CHANCES will use the new 4MOST Spectroscopic Survey Facility on the VISTA 4m telescope to obtain spectra for ∼500 000 galaxies with magnitudes rAB < 20.4, providing comprehensive spectroscopic coverage of each cluster out to 5r200. Its wide and deep scope will trace massive and dwarf galaxies from the surrounding filaments and groups to the cores of galaxy clusters. This will enable the study of galaxy preprocessing and of the role of the evolving environment on galaxy evolution. In this paper, we present and characterise the sample of clusters and superclusters to be targeted by CHANCES. We used literature catalogues based on X-ray emission and the Sunyaeva-Zel'dovich effect to define the cluster sample in a homogeneous way, with attention to cluster mass and redshift, as well as the availability of ancillary data. We calibrated literature mass estimates from various surveys against each other and provide an initial mass estimate for each cluster, which we used to define the radial extent of the 4MOST coverage. We also present an initial assessment of the structure surrounding these clusters based on the redMaPPer red-sequence algorithm as a preview of some of the science CHANCES will enable. © The Authors 2025
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    Galaxy evolution in compact groups: II. Witnessing the influence of major structures in their evolution
    (EDP Sciences, 2025-04) Montaguth, Gissel P.; Monachesi, Antonela; Torres-Flores, Sergio; Gómez, Facundo A.; Lima-Dias, Ciria; Cortesi, Arianna; Mendes De Oliveira, Claudia; Telles, Eduardo; Panda, Swayamtrupta; Grossi, Marco; Lopes, Paulo A. A.; O'Mill, Ana Laura; Hernandez-Jimenez, Jose A.; Olave-Rojas, Daniela E.; Demarco, Ricardo; Kanaan, Antonio; Ribeiro, Tiago; Schoenell, William
    Compact groups (CGs) of galaxies are an extreme environment for the morphological transformations and the cessation of star formation in galaxies. However, despite initially being conceived as isolated systems, it is now widely recognised that many of them are not as isolated as expected. Our objective is to understand the dynamics of CGs, as well as how the environment surrounding CGs impacts their morphological and physical properties. To achieve this, we selected a sample of 316 CGs in the Stripe 82 region, with a total of 1011 galaxies, and a sample of 2281 field galaxies as a control sample. We find that at least 41% of our sample of CGs are part of major structures, i.e. non-isolated CGs. We find a bimodality in the effective radius (Re)-Sérsic index (n) plane for all transition galaxies (those with (u - r) > 2:3 and n < 2:5) in CGs. Additionally, transition galaxies in isolated CGs populate more densely the Re-n plane for n < 1:75. In contrast, transition galaxies in non-isolated CGs show a bimodal distribution in the Re-n plane, with the n values smoothly increasing towards higher values, and 62% of these galaxies having n > 1:5. This indicates that the majority of these galaxies have already undergone a morphological transformation and primarily contribute to the population of more compact galaxies in the Re-n plane. We find that galaxies in our sample of CGs have a lower mean specific star formation rate (sSFR) compared to the control sample, with non-isolated CGs showing even lower sSFR values, indicating that dense environments suppress star formation. Additionally, non-isolated CGs have a higher fraction of quenched galaxies relative to isolated CGs and the control sample. Based on our results, we propose an evolutionary scenario where the major structures in which the CGs are embedded accelerate the morphological transformations of their galaxy members, and also facilitates preprocessing. Our findings highlight the importance of considering the larger structures in which CGs may be located, when analysing the properties of their galaxy members, as this can significantly affect the evolution of CGs and their galaxies. © The Authors 2025.