NSCs from groups to clusters: A catalogue of dwarf galaxies in the Shapley Supercluster and the role of environment in galaxy nucleation

Zanatta, Emilio J. B., Sanchéz-Janssen, Ruben, Souza, Rafael S. de, Chies-Santos, Ana L. and Blakeslee, John P. (2024) NSCs from groups to clusters: A catalogue of dwarf galaxies in the Shapley Supercluster and the role of environment in galaxy nucleation. Monthly Notices of the Royal Astronomical Society (MNRAS), 530 (3): stae849. pp. 2670-2687. ISSN 0035-8711
Copy

Nuclear star clusters (NSCs) are dense star clusters located at the centre of galaxies spanning a wide range of masses and morphologies. Analysing NSC occupation statistics in different environments provides an invaluable window into investigating early conditions of high-density star formation and mass assembly in clusters and group galaxies. We use HST/ACS deep imaging to obtain a catalogue of dwarf galaxies in two galaxy clusters in the Shapley supercluster: the central cluster Abell 3558 and the northern Abell 1736a. The Shapley region is an ideal laboratory to study nucleation as it stands as the highest mass concentration in the nearby Universe. We investigate the NSC occurrence in quiescent dwarf galaxies as faint as M I = −10 mag and compare it with all other environments where nucleation data is available. We use galaxy cluster/group halo mass as a proxy for the environment and employ a Bayesian logistic regression framework to model the nucleation fraction (f n) as a function of galaxy luminosity and environment. We find a notably high f n in Abell 3558: at M I ≈ −13.1 mag, half the galaxies in the cluster host NSCs. This is higher than in the Virgo and Fornax clusters but comparable to the Coma Cluster. On the other hand, the f n in Abell 1736a is relatively lower, comparable to groups in the local volume. We find that the probability of nucleation varies with galaxy luminosity remarkably similarly in galaxy clusters. These results reinforce previous findings of the important role of the environment in NSC formation/growth.

visibility_off picture_as_pdf

picture_as_pdf
2403.14847v1.pdf
subject
Submitted Version
lock
Restricted to Repository staff only

Request Copy
picture_as_pdf

Published Version


Atom BibTeX OpenURL ContextObject in Span OpenURL ContextObject Dublin Core MPEG-21 DIDL Data Cite XML EndNote HTML Citation METS MODS RIOXX2 XML Reference Manager Refer ASCII Citation
Export

Downloads