Deep Galaxy Surveys

Co-Investigator

The JWST Emission Line Survey (JELS)

I am a co-investigator of the JWST Emission Line Survey Duncan et al. (2025), a deep NIRCam narrowband survey centred in the PRIMER COSMOS field that is designed to extend narrow-band rest-optical emission-line selection into the Epoch of Reionization (EoR) for the first time, and to enable unique studies of the resolved ionized gas morphology in individual galaxies across cosmic history.

Key results include:

  • Detailed studies on the integrated and resolved properties of Hα selected galaxies at z~6.1 - see Pirie et al. (2025) and Stephenson et al. (2025).
  • New constraints on the evolution of the Hα luminosity function at z~6.1 (Pirie et al., in prep).
  • Unbiased constraints on Lyman-α escape fraction combining the unique JELS Hα selection with deep MUSE spectroscopy (Patrick et al., in prep).

PEARLS

I am a co-investigator of the ‘Prime Extragalactic Areas for Reionization and Lensing Science’ (PEARLS) led by Prof. Rogier Windhorst. In particular, within this team I have led the planning and analysis of the NIRCam observations of the luminous high-redshift radio galaxy TNJ1338-1942.

The first paper based on these observations, Duncan et al. (2023), presents a resolved study of the radio galaxy host properties and the extensive jet activity.

HST and JWST imaging of the TNJ1338-1942 radio galaxy at z=4.1. The new NIRCam bands reveal the full extent of the jet-aligned emission that is dominated by strong nebular emission, while also allowing tight constraints on the host galaxy and its formation history.