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

Journal article

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.

Authors: Zhu, Y; Rieke, MJ; Ji, Z; Simmonds, C; Sun, F

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Astronomical Society
• Journal: The Astrophysical Journal
• Volume: 986
• Issue: 2
• Article number: 162
• Publication date: 2025-06-16
• Acceptance date: 2025-04-29
• DOI: 10.3847/1538-4357/add2f4
• EISSN: 1538-4357
• ISSN: 0004-637X
• Language: English
• Keywords: High-redshift galaxies; Galactic winds; Galaxy classification systems