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

For the first time, we systematically search for galaxies with extended emission line and potential outflows features using medium-band images in the GOODS-S field 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 $1 < z < 6$ , with a peak in the population near cosmic noon, benefiting from the good coverage of the medium-band filters. By examining their SEDs, we find that the candidate galaxies are at least $20\%$ more bursty in their star-forming activity and have $60\%$ 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 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.

eprint arXiv:2409.11464