NEXUS Survey Aims to Transform Understanding of Early Galaxies
The NEXUS project, formally titled "NEXUS: the North ecliptic pole EXtragalactic Unified Survey," is a comprehensive imaging and spectroscopic survey being conducted with the James Webb Space Telescope (JWST). This initiative spans multiple cycles (Cycles 3-5) and aims to utilize 368 primary hours of observation time. The survey is structured into two overlapping tiers: a Wide tier covering approximately 400 arcminutes², which will conduct Near-Infrared Camera (NIRCam) spectroscopy across three epochs over three years; and a Deep tier, which will focus on high-multiplexing NIRSpec spectroscopy for around 10,000 targets over 18 epochs with a two-month cadence.
The Wide tier aims to achieve a signal-to-noise ratio greater than 3 at a magnitude of F444W < 22.2, while the Deep tier targets a signal-to-noise ratio greater than 3 at F200W magnitudes less than 27/29. Both tiers will also include simultaneous multi-band imaging using NIRCam and Mid-Infrared Instrument (MIRI) with depths of approximately 28-29 in NIRCam and about 25 in MIRI.
NEXUS will focus on three primary scientific objectives. Firstly, it will classify and characterize galaxies and active galactic nuclei (AGNs) from redshifts around 1 to the Cosmic Dawn. Secondly, it will facilitate systematic time-domain investigations, particularly of transients and low-mass AGN reverberation mapping at redshifts greater than 3. Lastly, the extensive dataset generated will support knowledge transfer to other legacy fields, create data challenges, and lay the groundwork for future space missions.
The project is positioned within the continuous viewing zone of JWST and is fully covered by the Euclid Ultra-Deep Field, which will enhance the depth of spectroscopy and photometry available for analysis. NEXUS aims to engage the broader astronomical community through rapid public releases of processed data and an open invitation for collaboration, potentially driving significant advancements in various key areas of astronomy.
For further details, the paper can be accessed at arXiv:2408.12713.