Looking into the faintEst WIth MUSE (LEWIS): Exploring the nature of ultra-diffuse galaxies in the Hydra-I cluster IV. A study of the globular cluster population in four ultra-diffuse galaxies
: Mirabile, Marco; Cantiello, Michele; Rejkuba, Marina; Mieske, Steffen; Iodice, Enrichetta; Buttitta, Chiara; Luisa Buzzo, Maria; Hartke, Johanna; Doll, Goran; Rossi, Luca; Arnaboldi, Magda; Branchesi, Marica; D'Ago, Giuseppe; Falcon-Barroso, Jesus; Fahrion, Katja; Forbes, Duncan A.; Gullieuszik, Marco; Hilker, Michael; Lohmann, Felipe S.; Paolillo, Maurizio; Riccio, Gabriele; Richtler, Tom; Spavone, Marilena
Publisher: EDP Sciences
: 2026
Astronomy and Astrophysics
: A117
: 705
: 0004-6361
: 1432-0746
DOI: https://doi.org/10.1051/0004-6361/202556180
: https://doi.org/10.1051/0004-6361/202556180
: https://research.utu.fi/converis/portal/detail/Publication/509018983
Context. As some of the oldest stellar systems in the Universe, globular clusters (GCs) are key fossil tracers of galaxy formation and interaction histories. This paper is part of the LEWIS project, which provides the first homogeneous MUSE integral-field spectroscopic survey of a complete sample of ultra-diffuse galaxies (UDGs) in the Hydra I cluster. Aims. We use MUSE spectroscopy and new VIRCAM H-band imaging data to study the GC populations and dark matter content in four dwarf galaxies from the LEWIS sample, which were found to host several GC candidates based on previous photometric studies. Methods. We retrieved line-of-sight velocities (LOSVs) for all the sources in the observed MUSE fields and classified them based on their spectral features and LOSVs. Because the spectroscopic measurements are limited to relatively bright sources (m(H) less than or similar to 23.5 AB mag), we developed a multi-band photometric procedure to identify additional GC candidates that are too faint for spectroscopic confirmation. GC candidates were selected based on a combination of photometric properties (colors, magnitudes) and morphometric criteria (shape and size). The same selection criteria were applied to empty fields to estimate a statistical background correction for the number of identified GC candidates. Additionally, H-band observations were used to constrain the stellar masses of the studied galaxies. Results. Based on the spectroscopic classification, we confirm one GC in UDG 3, two in UDG 7, and four in UDG 11, while UDG 9 has no spectroscopically confirmed bright GCs. We identify four intracluster GCs in the vicinity of UDG 3 and UDG 11, and one ultra-compact dwarf (UCD) with a radial velocity only -85 +/- 10 km/s different from that of UDG 7 and thus possibly bound to it. Considering the completeness correction and accounting for possible contamination by unresolved background galaxies, from the photometry we estimate that the number of GCs ranges between 0 and similar to 40 for the investigated UDGs. Their specific frequencies suggest that three out of four UDGs are either GC rich, similar to those in the Coma cluster, or belong to an intermediate population, as seen in the Perseus cluster. Dark matter content estimates, inferred from GC counts and stellar mass, indicate that these galaxies are dark matter dominated, with dynamical-to-stellar mass ratios ranging from similar to 10 - 1000.
:
Part of this work was supported through the INAF “Astrofisica Fondamentale” GO-grant 2024 n. 12 (PI: M. Cantiello). MM acknowledges support from the ESO Short-Term Visiting Program (SSDF 22/18, PI: S. Mieske) and the ESO Studentship Program. MC acknowledges support from the ASI–INAF agreement “Scientific Activity for the Euclid Mission” (n. 2024-10-HH.0; WP8420) and from the ESO Scientific Visitor Programme. KF acknowledges funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement Number 101103830. DAF thanks the ARC via DP220101863. GD acknowledges support by UKRI-STFC grants: ST/T003081/1 and ST/X001857/1. GR acknowledges support INAF “Astrofisica Fondamentale” Mini-grant 2024 n.17/RSN1 (PI G. Riccio) and support from the INAF LSST in-kind project (ITA-INA S6, PI:Michele Cantiello). J.F-B. acknowledges support from the PID2022-140869NB-I00 grant from the Spanish Ministry of Science and Innovation. TR acknowledges support from ANID via Nucleo Milenio TITANs (NCN 2023-002). MS acknowledge the support by the Italian Ministry for Education University and Research (MIUR) grant PRIN 2022 2022383WFT “SUNRISE”, CUP C53D23000850006 and by VST funds. This work is based on observations collected at the European Southern Observatory under ESO programmes 108.222P.001, 108.222P.002, 108.222P.003, 097.B-0806(A), 094.B-0711A, 109.231E.001. This research has made use of the NASA/IPAC Extragalactic Database (NED), which is funded by the National Aeronautics and Space Administration and operated by the California Institute of Technology. We also acknowledge the usage of the Extragalactic Distance Database (EDD, https://edd.ifa.hawaii.edu/). We made extensive use of the softwares of SExtractor (Bertin & Arnouts 1996) and Topcat (https://www.star.bris.ac.uk/ mbt/topcat/; Taylor 2005). This research has made use of the VizieR catalog access tool, CDS, Strasbourg, France (Ochsenbein 1996). The original description of the VizieR service was published in Ochsenbein et al. (2000). This publication makes use of data products from the Pan-STARRS1 Surveys (PS1) and the PS1 public science archive have been made possible through contributions by the Institute for Astronomy, the University of Hawaii, the Pan-STARRS Project Office, the Max-Planck Society and its participating institutes, the Max Planck Institute for Astronomy, Heidelberg and the Max Planck Institute for Extraterrestrial Physics, Garching, The Johns Hopkins University, Durham University, the University of Edinburgh, the Queen’s University Belfast, the Harvard-Smithsonian Center for Astrophysics, the Las Cumbres Observatory Global Telescope Network Incorporated, the National Central University of Taiwan, the Space Telescope Science Institute, the National Aeronautics and Space Administration under Grant No. NNX08AR22G issued through the Planetary Science Division of the NASA Science Mission Directorate, the National Science Foundation Grant No. AST-1238877, the University of Maryland, Eotvos Lorand University (ELTE), the Los Alamos National Laboratory, and the Gordon and Betty Moore Foundation (Chambers et al. 2016; Magnier et al. 2020a,b,c; Waters et al. 2020; Flewelling et al. 2020). This publication makes use of data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation (Skrutskie et al. 2006).
