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

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 $r_{\mathrm{AB}},z_{\mathrm{AB}}<21.81$ 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 $\mathrm{lo}{\mathrm{g}}_{10}({\mathrm{M}}_{\ast }/{\mathrm{M}}_{\odot })\sim 9.69-10.75$ and star formation rates in the youngest age bin ranging from $\mathrm{lo}{\mathrm{g}}_{10}(SFR/({\mathrm{M}}_{\odot }\cdot \mathrm{y}{\mathrm{r}}^{-1}))\sim 0.39-1.46$, 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$\hat{I}\pm$ emissions, offering unique opportunities to study Ly$\hat{I}\pm$ emitters at high redshift in future work.

20 pages, 10 figures