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arXiv · 2405.12907

Deep HST/UVIS imaging of the candidate dark galaxy CDG-1

Pieter van Dokkum·Dayi David Li·Roberto Abraham·Shany Danieli·Gwendolyn M. Eadie·William E. Harris·Aaron J. Romanowsky
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Abstract

CDG-1 is a tight grouping of four likely globular clusters in the Perseus cluster, and a candidate dark galaxy with little or no diffuse light. Here we provide new constraints on the luminosity of any underlying stellar emission, using HST/UVIS F200LP imaging. No diffuse emission is detected, with a 2$σ$ upper limit of F200LP>28.1 mag/arcsec$^2$ on the 5'' scale of CDG-1. This surface brightness limit corresponds to a 2$σ$ lower limit of >0.5 for the fraction of the total luminosity that is in the form of globular clusters. The most likely alternative, although improbable, is that CDG-1 is a chance grouping of four globular clusters in the halo of the Perseus galaxy IC312.

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Pieter van Dokkum, Dayi David Li, Roberto Abraham, Shany Danieli, Gwendolyn M. Eadie, William E. Harris, Aaron J. Romanowsky. 2024-05-21. Deep HST/UVIS imaging of the candidate dark galaxy CDG-1. https://doi.org/10.3847/2515-5172%2Fad4be6

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