A Systematic Search for Galaxies with Extended Emission Lines and Potential Outflows in JADES Medium-band Images
Yongda Zhu, Marcia Rieke, Zhiyuan Ji, Charlotte Simmonds, Fengwu Sun, Yang Sun, Stacey Alberts, Rachana Bhatawdekar, Andrew J. Bunker, Phillip A. Cargile, Stefano Carniani, Anna de Graaff, Kevin Hainline, Jakob M. Helton, Gareth C. Jones, Jianwei Lyu, G. H. Rieke, Pierluigi Rinaldi, Brant Robertson, Jan Scholtz, Hannah Übler, Christina C. Williams, Christopher N. A. Willmer
Abstract
Abstract For the first time, we present a systematic search for galaxies with extended emission lines and potential outflow features using JWST medium-band images in the GOODS South field. This is done by comparing the morphology in medium-band images to adjacent continuum and UV bands. We look for galaxies that have a maximum extent 50% larger, an excess area 30% greater, or an axis ratio difference of more than 0.3 in the medium band compared to the reference bands. After visual inspection, we find 326 candidate galaxies at 1.4 < z < 8.4, with a peak in the population near cosmic noon, benefiting from the good coverage of the medium-band filters. By fitting their spectral energy distributions, we find that the candidate galaxies are at least 20% more bursty in their star-forming activity and have 50% more young stellar populations compared to a control sample selected based on the continuum band flux. Additionally, these candidates exhibit a significantly higher production rate of ionizing photons. We further find that candidates hosting known active galactic nuclei (AGN) produce extended emission that is more anisotropic compared to non-AGN candidates. A few of our candidates have been spectroscopically confirmed to have prominent outflow signatures through NIRSpec observations, showcasing the robustness of the photometric selection. Future spectroscopic follow-up will better help verify and characterize the kinematics and chemical properties of these systems.