COOL-LAMPS IV: A Sample of Bright Strongly-Lensed Galaxies at $3 < z < 4$

TL;DR

This paper reports the discovery and detailed analysis of five bright, strongly-lensed galaxies at redshifts 3 to 4, nearly doubling the known sample, and provides insights into their physical properties and star formation activity.

Contribution

It presents a new sample of bright lensed galaxies at high redshift, with detailed modeling of their properties and lensing magnifications, expanding the understanding of galaxy evolution in this epoch.

Findings

Magnifications range from ~29 to ~180.

Stellar masses are log10(M*/M_sun) ~ 9.69 to 10.75.

Star formation rates are log10(SFR) ~ 0.39 to 1.46.

Abstract

We report the discovery of five bright strong gravitationally lensed galaxies at $3 < z < 4$: COOLJ0101$+$2055 ($z = 3.459$), COOLJ0104$-$0757 ($z = 3.480$), COOLJ0145$+$1018 ($z = 3.310$), COOLJ0516$-$2208 ($z = 3.549$), and COOLJ1356$+$0339 ($z = 3.753$). These galaxies have magnitudes of $r_{\rm AB}, z_{\rm AB} < 21.81$ mag and are lensed by galaxy clusters at $0.26 < z < 1$. This sample nearly doubles the number of known bright lensed galaxies with extended arcs at $3 < z < 4$. We characterize the lensed galaxies using ground-based grz/giy imaging and optical spectroscopy. We report model-based magnitudes and derive stellar masses, dust content, and star-formation rates via stellar population synthesis modeling. Building lens models based on ground-based imaging, we estimate source magnifications in the range $\sim$29 to $\sim$180. Combining these analyses, we derive demagnified stellar masses in the range $\rm log_{10}(M_{*}/M_{\odot}) \sim 9.69 - 10.75$ and star formation rates in the youngest age bin ranging from $\rm log_{10}(SFR/(M_{\odot}\cdot yr^{-1})) \sim 0.39 - 1.46$, placing the sample galaxies on the massive end of the star-forming main sequence in this redshift interval. In addition, three of the five galaxies have strong Ly$\alpha$ emissions, offering unique opportunities to study Ly$\alpha$ emitters at high redshift in future work.