CEERS Observing Modes

CEERS is obtaining imaging and spectroscopy of the Extended Groth Strip (EGS) HST legacy field with five parallel JWST modes with three instruments:

NIRCam

NIRSpec

MIRI


The CEERS observations are schedulable in June and December (with a 180° flip). We are obtaining observations in two epochs, with four MIRI + NIRCam imaging pointings observed in June 2022, and the remaining six NIRSpec MSA + NIRCam imaging and four NIRCam grism + MIRI imaging scheduled for December 2022.

We show here the complete survey layout (left), separating the June observations (middle) and the scheduled December observations (right).

(Click image to enlarge.)

Click below to download a zipped file containing NIRCam, NIRSpec and MIRI pointing maps for each configuration. These maps are approximate, good to within ~10".

Download June pointing maps
Download December pointing maps
Download full survey NIRCam pointing maps


Click below to download the list of objects which received NIRSpec MSA slits in our original Aug 2017 APT submission. This is just one realization of what the final configuration will be, but it gives a rough idea of the numbers of which types of sources will receive slits.

Download MSA slit catalog
Download MSA slit region file


Download CEERS APT File
Download CEERS Public PDF

NIRCam

The NIRCam observing strategy is set by the primary science goal of detecting a large sample of z~9-13 galaxies. CEERS is based on 10 NIRCam pointings covering ~100 square arcmin of the EGS field. CEERS will obtain:

  • NIRCam imaging in 10 pointings, pairing the SW and LW filters. The following represent the planned 5σ point source depths per filter.
  • SW FilterDepth
    (5σ pt. source)
    LW FilterDepth
    (5σ pt. source)
    F115W29.15 F277W29.15
    F150W28.9 F356W28.95
    F200W28.97 F444W28.6
    F410M*28.4

    * F410M will be obtained for the 6 NIRCam pointings that do not use the Slitless Spectroscopy mode.

  • F115W + F150W + F200W will probe the Lyα break and will be paired with the LWF filters F277W, F356W and F444W at no cost.
  • Additional F115W imaging will increase the dynamic range of the detectable Lyα breaks.
  • In 4 fields, these additional F115W exposures are paired with the grism (R~1500), allowing the measurement of spectroscopic redshifts of z>4 star-forming galaxies and the calibration of NIRSpec slit losses
  • In the remaining 6 fields, the additional exposures will be paired with F410W, which acts as a narrow-band filter for [OIII] emission at 6.7 < z < 7.6

NIRSpec

The NIRSpec MSA observations address diverse goals: measuring redshifts of high-priority distant galaxies, characterizing ISM and AGN evolution, and testing JWST observing strategies for Cycle 2. CEERS will observe 6 pointings with R~1000 and 4 pointings with R~100. The NIRSpec strategy includes:

  • Orientation and tiling to maximize overlap with NIRCam and HST;
  • R=1000 at 3 grating settings efficiently characterizes emission-line strengths;
  • Diverse, high-priority targets with most lacking spectroscopic redshifts;
  • Prism observations for efficient measurement of broad continuum features;
  • Testing the impact of object centering through small dithers.

MIRI

The MIRI observations address two goals:

  • In the three MIRI pointings overlaping the NIRCam mosaic, we aim for 5σ detections of the highest–redshift candidates in F560W and F770W, achieving long-wavelength constraints on z=4-10 candidate SEDs.
  • In the remaining three pointings, we will use the continuous wavelength coverage of F770W, F1000W, F1280W, F1500W, F1800W and F2100W to study the rest-mid-IR features of galaxies, providing constraints on SFR & AGN diagnostics at z=1-3.
FilterDepth
(5σ pt. source)
Pointing*
F560W26.26,8,10   (1,3,5)
F770W26.0 / 26.2 / 25.56,8 / 10 / 9   (1 / 3,5 / 4)
F1000W24.85,7,9   (2,4,6)
F1280W24.35,7,9   (2,4,6)
F1500W23.85,7,9   (2,4,6)
F1800W22.95,7,9   (2,4,6)
F2100W21.6 / 21.85,7 / 9   (2 / 4,6)

* Pointing numbers refer to the June configuration. December pointing IDs are in parentheses.