The physics of galaxy assembly: WIDE MOS survey

Program leads: Michael Maseda and Bernd Husemann

Program duration: 106 hours

This WIDE MOS survey lays out the widest-area portion of the NIRSpec MSA GTO galaxy evolution program, based on the premise that even the fastest (overhead-sensible) tiling of the sky with JWST/NIRSpec MOS opens up an observational discovery space that is unattainable by other means and scientifically compelling. The WIDE MOS survey will cover a total of 31 pointings observed with the low spectral resolution PRISM/CLEAR setting (40min integration) and the high-resolution G235H/F170LP and G395H/F290LP settings (30 min integration each).

This program will provide continuum spectra for all sources in the targeted CANDELS fields with mF160W < 24.0 mag (AB) and z>2 (low spectral resolution setting, ~50 objects per field of view); emission line spectra (both low and high spectral resolution settings, ~200objects per field of view) for all objects with SED-expected H-emission lines fluxes > 10^-17 ergs/s/cm2 (corresponding to star formation rates of 6 Msun/yr at z~3).

The main science drivers are:

1) a survey of 1-5micron stellar continua at 10x higher resolution than photometry affords, constrainingand calibrating SFR's and stellar population ages,

2) a comprehensive 1-5micron survey of emission lines, to characterize the emission line properties (SFR, excitation and possibly [Fe/H]) of galaxies (mostly at z>4), and

3) to systematically explore the population incidence of ionized gas outflowsand kinematics of galaxies over a large range of properties and redshifts.

This survey can also become an excellent (and possibly rapid) legacy data set for follow-up by the GTO team and the community.


Observations and proposals:

Region Proposal Number of fields Region Proposal Number of fields




COSMOS #1214 5



#1212 7 UDS #1215




#1213 5      


Usual word of caution: in MOS mode, the exact position and orientation of the observations as well as the list of observed targets depend on when the observations are scheduled and often on the output of the associated NIRCam imaging. Therefore, they will only be known much later.