RELICS-DP7: Spectroscopic Confirmation of a Dichromatic Primeval Galaxy at z ∼ 7

We report the discovery of a spectroscopically-confirmed strong Lyman-$\alpha$ emitter at $z=7.0281\pm0.0003$, observed as part Reionization Cluster Lensing Survey (RELICS). This galaxy, dubbed "Dichromatic Primeval Galaxy" $z\sim7$ (DP7), shows two distinct components. While fairly unremarkable in terms its ultraviolet (UV) luminosity ($\sim0.3L^{\ast}_{UV}$, where $L^{\ast}_{UV}$ is characteristic luminosity), DP7 has one highest equivalent widths (EWs) among emitters $z>6$ ($>200$ Angstrom rest frame). The emission generally suggests young metal-poor, low-dust galaxy; however, we find that UV slope $\beta$ galaxy whole redder than typical star-forming galaxies these redshifts, $-1.13\pm 0.84$, likely indicating, on average, considerable amount dust obscuration, or an older stellar population. When measure for components separately, evidence differing colors, suggesting separate populations. Also, spatially extended and larger size, hinting to possible existence halo. Rejuvenation merging events could explain results. Either scenario requires extreme population, possibly including component Population III stars, obscured Active Galactic Nucleus. DP7, with low high EW, represents are thought be major contribution reionization Universe, this reason excellent target follow-up James Webb Space Telescope.