The ALPINE-CRISTAL-JWST Survey: JWST/IFU Optical Observations for 18 Main-Sequence Galaxies at z=4-6

TL;DR

The paper introduces the ALPINE-CRISTAL-JWST survey, a pioneering multi-wavelength, kiloparsec-scale study of 18 massive main-sequence galaxies at $z=4-6$, combining JWST/NIRSpec IFU spectroscopy, JWST/NIRCam imaging, HST data, and high-resolution ALMA observations to map stars, gas, and dust. It establishes a post-EoR benchmark to connect early galaxy formation with mature systems by delivering spatially resolved measurements of ionized gas, metallicity, dust attenuation, and kinematics, alongside integrated star formation indicators and CGM halo properties. Initial results show metallicities of $12+\log(O/H)\sim7.7-8.5$ (roughly $0.1-0.7\,Z_\odot$) with little evidence for evolution in metal content at fixed mass between $z\sim3.5$ and $z\sim7.5$, and reveal AGN activity in several targets alongside extended H$\alpha$ halos and [C II] halos indicating strong feedback and CGM enrichment. The dataset and methods enable detailed investigations of star formation modes, ISM/CGM coupling, and black hole growth in the early universe, with numerous follow-up papers planned to exploit resolved metallicity maps, gas kinematics, dust properties, and halo phenomena.

Abstract

To fully characterize the formation and evolution of galaxies, we need to observe their stars, gas, and dust on resolved spatial scales. We present the ALPINE-CRISTAL-JWST survey, which combines kpc-resolved imaging and spectroscopy from HST, JWST, and ALMA for 18 representative main-sequence galaxies at z=4-6 and log(M/$M_\odot$) > 9.5 to study their star formation, chemical properties, and extended gas reservoirs. The co-spatial measurements resolving the ionized gas, molecular gas, stars, and dust on 1-2 kpc scales make this a unique benchmark sample for the study of galaxy formation and evolution at $z\sim5$, connecting the Epoch of Reionization with the cosmic noon. In this paper, we outline the survey goals and sample selection, and present a summary of the available data for the 18 galaxies. In addition, we measure spatially integrated quantities (such as global gas metallicity), test different star formation rate indicators, and quantify the presence of H$α$ halos. Our targeted galaxies are relatively metal rich (10-70% solar), complementary to JWST samples at lower stellar mass, and there is broad agreement between different star formation indicators. One galaxy has the signature of an active galactic nuclei (AGN) based on its emission line ratios. Six show broad H$α$~emission suggesting type 1 AGN candidates. We conclude with an outlook on the exciting science that will be pursued with this unique sample in forthcoming papers.

Figures (21)

• Figure 1: The spectrum of a typical $z=5$ galaxy overlaid with wavelength regimes of physical interest. A selection of ground and space-based facilities are highlighted (including past missions like Spitzer and Herschel). The wavelength regions that are observed by the available data of the ALPINE-CRISTAL-JWST survey sample are shown as magenta boxes. We note the lack of observations at mid-IR and far-IR wavelength, covering warm dust emission and Polycyclic Aromatic Hydrocarbons (PAHs), important tracers of the dust grain distribution, at high redshifts. This wavelength range may be filled in by future facilities such as PRIMA glenn25.
• Figure 2: Collage of the $18$ targets part of the ALPINE-CRISTAL-JWST sample. For each panel, the background shows the COSMOS-Web JWST/NIRCam F277W image (except for DC-417567 for which we show HST WFC3/F160W). The H$\alpha$ map from JWST/NIRSpec IFU observations is indicated with the white contours. The CRISTAL ALMA data are shown as cyan contours ([C ii]: solid; $158\,{\rm \mu m}$ continuum: dashed). The contours show 3, 5, 10, 20, 40, and 50$\sigma$ levels for JWST and 3, 10, 20$\sigma$ levels for ALMA data. The ALMA (cyan) and NIRSpec/NIRCam (white) beam/PSF are indicated in all panels.
• Figure 3: The $18$ targets of the ALPINE-CRISTAL-JWST survey on the stellar mass vs. SFR plane. The targets are shown with large symbols, split in $z<5$ (blue) and $z>5$ (red) sub-samples. The redshift distribution is shown in the inset. Furthermore, we indicate rotators/dispersion-dominated (open circles) and mergers (solid squares) identified by low-resolution $\sim1\arcsec$ [C ii] kinematics data romano21. Candidate type 1 (broad-line) AGN are indicated with a star ren25. The ALPINE parent sample is shown as small white circles faisst20b. In addition, we show galaxies at $z\sim5$ from the COSMOS2020 catalog weaver22 as well as various JWST-detected galaxies at $z=4-6$ from the literature (small gray squares; see text for references).
• Figure 4: Stacked spectrum of all $18$ ALPINE-CRISTAL-JWST survey targets (note that the $y$-axis is broken at $4\,{\rm \mu Jy}$ to make the higher fluxes better visible). Some prominent and common emission lines are indicated by the vertical dashed lines. The spectra have been continuum subtracted before stacking. More details on the derivation of the spectra can be found in Section \ref{['sec:measurements']}.
• Figure 5: H$\alpha$ emission line maps derived from the NIRSpec/IFU observations for the $18$ galaxies in the ALPINE-CRISTAL-JWST sample. The line maps are cut off at $5\sigma$. The white contours show the rest-frame optical light (JWST/NIRCam F277W and HST WFC3/F160W for DC-417567) and cyan contours show [C ii] emission from the ALMA-CRISTAL program. The orange-dashed contours show the ALMA $158\,{\rm \mu m}$ continuum dust emission. The contours show 5, 10, 20, 40, and 50$\sigma$ levels for JWST and 3, 10, 20$\sigma$ levels for ALMA data. The ALMA (cyan) and NIRSpec (white) beam/PSF are indicated in all panels.