A Systematic Search for Galaxies with Extended Emission Line and Potential Outflows in JADES Medium-band Images

For the first time, we present a systematic search for galaxies with extended emission lines and potential outflows 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.

The Astrophysical Journal, Volume 986, Issue 2, id.162, 18 pages