The gas and stellar content of a metal-poor galaxy at $z=8.496$ as revealed by JWST and ALMA

Abstract

We present a joint analysis of the galaxy S04590 at $z=8.496$ based on NIRSpec, NIRCam, and NIRISS observations obtained through as part of Early Release Observations programme of the James Webb Space Telescope (JWST) and the far-infrared [CII]-$158\mu$m emission line detected by dedicated Atacama Large Millimeter/submillimeter Array (ALMA) observations. We determine the physical properties of S04590 from modelling of the spectral energy distribution (SED) and through the redshifted optical nebular emission lines detected with JWST/NIRSpec. The best-fit SED model reveals a low-mass ($M_{\star }=10^{7.2}-10^8{M}_{\odot }$) galaxy with a low oxygen abundance of $12+\log (O/H)=7.16_{-0.12}^{+0.10}$ derived from the strong nebular and auroral emission lines. Assuming that [CII] effectively traces the interstellar medium (ISM), we estimate the total gas mass of the galaxy to be $M_{\mathrm{gas}}=(8.0\pm 4.0)\times 10^8{M}_{\odot }$ based on the luminosity and spatial extent of [CII]. This yields an exceptionally high gas fraction, $f_{\mathrm{gas}}=M_{\mathrm{gas}}/(M_{\mathrm{gas}}+M_{\star })\gtrsim 90\%$, though still consistent within the range expected for its low metallicity. We further derive the metal mass of the galaxy based on the gas mass and gas-phase metallicity, which we find to be consistent with the expected metal production from Type II supernovae. Finally, we make the first constraints on the dust-to-gas (DTG) and dust-to-metals (DTM) ratios of galaxies in the epoch of reionization at $z\gtrsim 6$, showing overall low mass ratios of logDGT $<-3.8$ and logDTM $<-0.5$, though consistent with local scaling relations and in particular the local metal-poor galaxy I Zwicky 18. Our analysis highlights the synergy between ALMA and JWST in characterizing the gas, metal, and stellar content of the first generation of galaxies.

Accepted for publication in ApJL

References in corpus (61)

• Array Programming with NumPy
• Infrared Emission from Interstellar Dust. IV. The Silicate-Graphite-PAH Model in the Post-Spitzer Era
• A Highly Consistent Framework for the Evolution of the Star-Forming "Main Sequence" from z~0-6
• The Near-Infrared Spectrograph (NIRSpec) on the James Webb Space Telescope I. Overview of the instrument and its capabilities
• Understanding Galaxy Evolution through Emission Lines
• The Mass-Metallicity and the Fundamental Metallicity Relation revisited on a fully Te-based abundance scale for galaxies
• The Cosmic Baryon and Metal Cycles
• The chemical enrichment in the early Universe as probed by JWST via direct metallicity measurements at z~8
• The MOSDEF Survey: The Evolution of the Mass-Metallicity Relation from $z=0$ to $z\sim 3.3$
• The ALPINE-ALMA [CII] Survey: data processing, catalogs, and statistical source properties
• The JWST Early Release Observations
• The Herschel Dwarf Galaxy Survey: I. Properties of the low-metallicity ISM from PACS spectroscopy
• Galaxy Formation and Reionization: Key Unknowns and Expected Breakthroughs by the James Webb Space Telescope
• Reionization Era Bright Emission Line Survey: Selection and Characterization of Luminous Interstellar Medium Reservoirs in the z>6.5 Universe
• A dynamically cold disk galaxy in the early Universe
• Tracing the total molecular gas in galaxies: [CII] and the CO-dark gas
• First look with JWST spectroscopy: $z\sim 8$ galaxies resemble local analogues
• The ALPINE-ALMA [CII] survey. Little to no evolution in the [CII]-SFR relation over the last 13 Gyr
• Dynamical properties of z $\sim 4.5$ dusty star-forming galaxies and their connection with local early type galaxies
• Star formation rate and dynamical mass of 10^8 solar mass black hole host galaxies at redshift 6
• The REBELS ALMA Survey: cosmic dust temperature evolution out to z $\sim$ 7
• Gravitationally Lensed Galaxies at 2<z<3.5: Direct Abundance Measurements of Lya Emitters
• A First Look at the Abundance Pattern -- O/H, C/O, and Ne/O -- in $z>7$ Galaxies with JWST/NIRSpec
• A Herschel [CII] Galactic plane survey III: [CII] as a tracer of star formation
• The ALMA REBELS Survey: Dust Continuum Detections at z > 6.5
• The ALMA REBELS Survey: the dust content of $z\sim 7$ Lyman Break Galaxies
• The Kinematics of z ~ 6 Quasar Host Galaxies
• The ALPINE-ALMA [CII] survey: Molecular gas budget in the Early Universe as traced by [CII]
• The Origins of [CII] Emission in Local Star-forming Galaxies
• Missing [CII] emission from early galaxies
• Kinematics of $z\ge 6$ galaxies from [CII] line emission
• Star formation histories of UV-luminous galaxies at $z\simeq 6.8$: implications for stellar mass assembly at early cosmic times
• The ALMA REBELS Survey: The Dust-obscured Cosmic Star Formation Rate Density at Redshift 7
• The ALMA REBELS Survey. Epoch of Reionization giants: properties of dusty galaxies at $z\approx 7$
• A first look at the SMACS0723 JWST ERO: spectroscopic redshifts, stellar masses and star-formation histories
• Evolution of the dust-to-metals ratio in high-redshift galaxies probed by GRB-DLAs
• Detailed dust modelling in the L-Galaxies semi-analytic model of galaxy formation
• The ALMA REBELS Survey: Specific Star-Formation Rates in the Reionization Era
• Finding Peas in the Early Universe with JWST
• First Insights into the ISM at $z>8$ with JWST: Possible Physical Implications of a High [O III]$\lambda 4363$/[O III]$\lambda 5007$
• Accurate dust temperature determination in a $z=7.13$ galaxy
• Dust scaling relations in a cosmological simulation
• Dust temperature in ALMA $\hbox{[C $\scriptstyle\rm II $]}$-detected high-$z$ galaxies
• The origin of dust in galaxies across cosmic time
• HI-MaNGA: Tracing the physics of the neutral and ionized ISM with the second data release
• Deep ALMA redshift search of a z~12 GLASS-JWST galaxy candidate
• The Mass-Metallicity Relation at z=8: Direct-Method Metallicity Constraints and Near-Future Prospects
• Dynamical characterization of galaxies up to $z\sim 7$
• The Nature of High ${[\mathrm{OIII}]}_{88\mu \mathrm{m}}$/${[\mathrm{CII}]}_{158\mu \mathrm{m}}$ Galaxies in the Epoch of Reionization: Low Carbon Abundance and a Top-Heavy IMF?
• ALMA reveals extended cool gas and hot ionized outflows in a typical star-forming galaxy at $z=7.13$
• Physical constraints on the extended interstellar medium of the z=6.42 quasar J1148+5251: [CII] 158um, [NII] 205um and [OI] 146um observations
• Tracing Molecular Gas in z $\simeq$ 6 Galaxies with [C$\mathrm{II}$]
• Astraeus V: The emergence and evolution of metallicity scaling relations during the Epoch of Reionization
• First JWST observations of a gravitational lens: Mass model from new multiple images with near-infrared observations of SMACS J0723.3-7327
• The ALMA REBELS Survey: The Cosmic HI Gas Mass Density in Galaxies at $z\approx 7$
• Blue Rest-Frame UV-Optical Colors in z~8 Galaxies from GREATS: Very Young Stellar Populations at ~650 Myr of Cosmic Time
• CO Emission, Molecular Gas, and Metallicity in Main-Sequence Star-Forming Galaxies at $z\sim 2.3$
• An upper limit on [OIII] 88 $\mu$m and 1.2 mm continuum emission from a JWST $z\approx 12-13$ galaxy candidate with ALMA
• Bridging Optical and Far-Infrared Emission-Line Diagrams of Galaxies from Local to the Epoch of Reionization: Characteristic High [O III] 88 $\mu \mathrm{m}$/SFR at $z>6$
• The resolved chemical abundance properties within the interstellar medium of star-forming galaxies at $\text{z}\approx 1.5$
• Observed cosmic evolution of galaxy dust properties with metallicity and tensions with models

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