Dissecting the RELICS cluster SPT-CLJ0615–5746 through intracluster light: Confirmation of the multiple merging state of the cluster formation
The intracluster light (ICL) fraction, measured at certain specific wavelengths, has been shown to provide a good marker for determining the dynamical stage of galaxy clusters, that is, merging versus relaxed, for low to intermediate redshifts. We apply it for the first time to a high-redshift syste...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2023 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/335830 |
| Acceso en línea: | http://hdl.handle.net/10261/335830 |
| Access Level: | acceso abierto |
| Palabra clave: | Galaxies: clusters: individual: SPT-CLJ0615–5746 Galaxies: clusters: intracluster medium Techniques: image processing |
| Sumario: | The intracluster light (ICL) fraction, measured at certain specific wavelengths, has been shown to provide a good marker for determining the dynamical stage of galaxy clusters, that is, merging versus relaxed, for low to intermediate redshifts. We apply it for the first time to a high-redshift system, SPT-CLJ0615–5746 at z = 0.97, using its Reionization Lensing Cluster Survey (RELICS) observations in the optical and infrared. We find the ICL fraction signature of the merging, with values ranging from 16 to 37%. A careful reanalysis of the X-ray data available for this cluster indicates at least one current and plausibly a second merger. These two results contradict previous works based on X-ray data, which claimed a relaxed state for SPT-CLJ0615–5746, and the results confirm the evidence presented by kinematic analyses. We also found an abnormally high ICL fraction in the rest-frame near-ultraviolet wavelengths, which may be attributed to the combination of several phenomena such as an ICL injection during recent mergers of stars with average early-type spectra, the reversed star formation-density relation found at this high redshift in comparison with lower-redshift clusters, and projection effects. © The Authors 2023. |
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