JEMS: A deep medium-band imaging survey in the Hubble Ultra-Deep Field with JWST NIRCam & NIRISS

Understand

We present JEMS (JWST Extragalactic Medium-band Survey), the first public medium-band imaging survey carried out using JWST/NIRCam and NIRISS.

• These observations use $\sim2\mu$m and $\sim4\mu$m medium-band filters (NIRCam F182M, F210M, F430M, F460M, F480M; and NIRISS F430M & F480M in parallel) over 15.6 square arcminutes in the Hubble Ultra Deep Field (UDF), thereby building on the deepest multi-wavelength public datasets available anywhere on the sky.
• We describe our science goals, survey design, NIRCam and NIRISS image reduction methods, and describe our first data release of the science-ready mosaics.
• Our chosen filters create a JWST imaging survey in the UDF that enables novel analysis of a range of spectral features potentially across the redshift range of $0.3<z<20$, including Paschen-$\alpha$, H$\alpha$+[NII], and [OIII]+H$\beta$ emission at high spatial resolution.