The JWST FRESCO survey: legacy NIRCam/grism spectroscopy and imaging in the two GOODS fields
Chisholm, J.; Wuyts, S.; Schaerer, D.; Xiao, M.; Brammer, G.; Oesch, P. A.; Matharu, J.; van Dokkum, P.; Marchesini, D.; Bouwens, R. J.; Illingworth, G. D.; Fudamoto, Y.; Reddy, N.; Shuntov, M.; Smit, R.; Labbe, I.; Lin, J.; Magee, D.; Stefanon, M.; Endsley, R.; Shivaei, I.; Mason, C.; Kerutt, J.; Wyithe, J. S. B.; Covelo-Paz, A.; Shapley, A.; Leonova, E.; Qin, Y.; Naidu, R. P.; Maseda, M.; Nelson, E.; Whitaker, K.; Weibel, A.; Meyer, R. A.; Sharma, R.; Matthee, J.; Giovinazzo, E.; Herard-Demanche, T.; Kramarenko, I.; Neufeld, C.; Prieto Lyon, G.
Switzerland, Denmark, United States, Netherlands, Australia, United Kingdom, Japan, Germany, Spain
Abstract
We present the JWST cycle 1 53.8 h medium program FRESCO, short for 'First Reionization Epoch Spectroscopically Complete Observations'. FRESCO covers 62 arcmin2 in each of the two GOODS/CANDELS fields for a total area of 124 arcmin2 exploiting JWST's powerful new grism spectroscopic capabilities at near-infrared wavelengths. By obtaining ~2 h deep NIRCam/grism observations with the F444W filter, FRESCO yields unprecedented spectra at R ~ 1600 covering 3.8-5.0 µm for most galaxies in the NIRCam field of view. This setup enables emission line measurements over most of cosmic history, from strong PAH lines at z ~ 0.2-0.5, to Pa α and Pa β at z ~ 1-3, He I and [S III] at z ~ 2.5-4.5, H α and [N II] at z ~ 5-6.5, up to [O III] and H β for z ~ 7-9 galaxies. FRESCO's grism observations provide total line fluxes for accurately estimating galaxy stellar masses and calibrating slit-loss corrections of NIRSpec/MSA spectra in the same field. Additionally, FRESCO results in a mosaic of F182M, F210M, and F444W imaging in the same fields to a depth of ~28.2 mag (5σ in 0${_{.}^{\prime\prime}}$32 diameter apertures). Here, we describe the overall survey design and the key science goals that can be addressed with FRESCO. We also highlight several, early science results, including: spectroscopic redshifts of Lyman break galaxies that were identified almost 20 yr ago, the discovery of broad-line active galactic nuclei at z > 4, and resolved Pa α maps of galaxies at z ~ 1.4. These results demonstrate the enormous power for serendipitous discovery of NIRCam/grism observations.