JWST NIRCam wide field slitless spectroscopy on the lensing cluster Abell 2744 : emission line detection for 5<z<7 and analysis of [OIII] emitting galaxies

Abstract

The nature of the first generation of stars is among the essential unknowns of in our understanding of the early Universe. Designed to study distant galaxies, the James Webb Space Telescope has offered a deeper glimpse into the first Billion Years of the Cosmos. It operates in the near and mid infrared wavelength regime, and, due to the high redshift of distant objects, covers restframe optical data for many galaxies.Still, low mass galaxies in the Early Universe are often below the detection limit.However, the Theory of General Relativity, governing the curvature of spacetime by matter, includes a mechanism for light magnification by massive structures. In particular, galaxy clusters enable large magnifications of background sources, allowing the detection of intrinsically faint objects. Here, as part of the ALT Survey (JWST program GO 3516, Cycle 2), I conduct asearch for dwarf galaxies with low interstellar metallicity with JWST NIRCam WideField Slitless Spectroscopy on the extensively observed lensing cluster Abell 2744. For a sample of ∼ 250 galaxies, I measure spectroscopic redshifts and flux of the nebular emission lines Hβ, [OIII]_4960 and [OIII]_5008. I present intriguing galaxies, focusing on the candidates for low oxygen abundance.Furthermore, I relate the emission line flux measurements to photometry inferred properties of the galaxies, and give an estimate for the mass-metallicity relation of the sample.