Speaker
Description
We present a detailed stellar population analysis of the strongly lensed dusty star-forming galaxy PLCK~G165.7+67.0 DSFG-1 (the ``Emerald'') at $z = 2.236$, using \textit{James Webb Space Telescope} (JWST) NIRCam imaging together with millimeter observations from the Submillimeter Array (SMA). The background source is multiply imaged into two components: image~1a, with a moderate magnification of $\mu \sim 5$, and image~1bc, which experiences extreme magnification of $\mu \sim 40$. SMA observations reveal exceptionally strong dust-continuum emission in image~1bc, indicating intense dust-obscured star formation on sub-kiloparsec scales. Based on integrated spectral energy distribution modeling, DSFG-1 exhibits a total star-formation rate of $81.6 \pm 11.0~M_{\odot}\,\mathrm{yr^{-1}}$ and a stellar mass of $M_{\star} \simeq 1.17 \times 10^{10}~M_{\odot}$, placing it $\sim$4 times above the star-forming main sequence at this redshift. Its size--mass relation and morphological properties are consistent with a late-type galaxy undergoing a starburst phase at Cosmic Noon. We further investigate the spatially resolved stellar population properties, revealing significant internal variations in stellar age and dust attenuation. These results point to a non-uniform star-formation history and highlight the complex interplay between dust geometry, stellar growth, and gravitational lensing. Overall, this work demonstrates the power of combining strong gravitational lensing with JWST observations to resolve the internal structure of heavily obscured galaxies in the early universe.