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arXiv · 2111.14882

RELICS: Small Lensed $z\geq5.5$ Galaxies Selected as Potential Lyman Continuum Leakers

Chloe Neufeld·Victoria Strait·Maruša Bradač·Brian C. Lemaux·Dan Coe·Lilan Yang·Tommaso Treu·Adi Zitrin·Mario Nonino·Larry Bradley·Keren Sharon
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Abstract

We present size measurements of 78 high-redshift ($z\geq 5.5$) galaxy candidates from the Reionisation Lensing Cluster Survey (RELICS). These distant galaxies are well-resolved due to the gravitational lensing power of foreground galaxy clusters, imaged by the Hubble Space Telescope (HST) and the Spitzer Space Telescope. We compute sizes using the forward-modeling code Lenstruction and account for magnification using public lens models. The resulting size-magnitude measurements confirm the existence of many small galaxies with effective radii $R_{\rm{eff}}<200$ pc in the early universe, in agreement with previous studies. In addition, we highlight compact and highly star-forming sources with star formation rate surface densities $\Sigma_\text{SFR}>10M_\odot\text{yr}^{-1}\text{kpc}^{-2}$ as possible Lyman continuum leaking candidates that could be major contributors to the process of reionisation. Future spectroscopic follow-up of these compact galaxies (e.g., with the James Webb Space Telescope) will further clarify their role in reionisation and the physics of early star formation.

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Chloe Neufeld, Victoria Strait, Maruša Bradač, Brian C. Lemaux, Dan Coe, Lilan Yang, Tommaso Treu, Adi Zitrin, Mario Nonino, Larry Bradley, Keren Sharon. 2021-11-29. RELICS: Small Lensed $z\geq5.5$ Galaxies Selected as Potential Lyman Continuum Leakers. https://doi.org/10.1093/mnras%2Fstac2280

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