The VANDELS survey: the relation between UV continuum slope and stellar metallicity in star-forming galaxies at z~3

Abstract

The estimate of stellar metallicities (Z*) of high-z galaxies are of paramount importance in order to understand the complexity of dust effects and the reciprocal interrelations among stellar mass, dust attenuation, stellar age, and metallicity. Benefiting from uniquely deep FUV spectra of >500 star-forming galaxies at redshifts 2<z<5 extracted from the VANDELS survey and stacked in bins of stellar mass (M*) and UV continuum slope (beta), we estimate their stellar metallicities Z* from stellar photospheric absorption features at 1501 and 1719 Angstrom, which are calibrated with Starburst99 models and are largely unaffected by stellar age, dust, IMF, nebular continuum or interstellar absorption. Comparing them to photometric based spectral slopes in the range 1250-1750 Angstrom, we find that the stellar metallicity increases by ~0.5 dex from beta ~ -2 to beta ~ -1 (1 < A(1600) < 3.2), and a dependence with beta holds at fixed UV absolute luminosity M(UV) and stellar mass up to 10^(9.65) Msun. As a result, the metallicity is a fundamental ingredient for properly rescaling dust corrections based on M(UV) and M*. Using the same absorption features, we analyze the mass-metallicity relation (MZR) and find it is consistent with the previous VANDELS estimation based on a global fit of the FUV spectra. Similarly, we do not find a significant evolution between z=2 and z=3.5. Finally, the slopes of our MZR and Z*-beta relation are in agreement with the predictions of well-studied semi-analytic models of galaxy formation (SAM), while some tensions with observations remain as to the absolute metallicity normalization. The relation between UV slope and stellar metallicity is fundamental for the exploitation of large volume surveys with next-generation telescopes and for the physical characterization of galaxies in the first billion years of our Universe.

25 pages, 4 tables, 16 figures, and 5 Appendix subsections; accepted for publication in A&A

References in corpus (20)

• Cosmic Star Formation History
• The hierarchical formation of the brightest cluster galaxies
• UV Luminosity Functions at redshifts z~4 to z~10: 10000 Galaxies from HST Legacy Fields
• Binary Population and Spectral Synthesis Version 2.1: construction, observational verification and new results
• Strong Nebular Line Ratios in the Spectra of z~2-3 Star-forming Galaxies: First Results from KBSS-MOSFIRE
• UV Luminosity Functions at z~4, 5, and 6 from the HUDF and other Deep HST ACS Fields: Evolution and Star Formation History
• Subaru Deep Survey V. A Census of Lyman Break Galaxies at z=4 and 5 in the Subaru Deep Fields: Photometric Properties
• The VIMOS Ultra-Deep Survey: ~10,000 galaxies with spectroscopic redshifts to study galaxy assembly at early epochs 2<z<~6
• GOODS-HERSCHEL: star formation, dust attenuation and the FIR-radio correlation on the Main Sequence of star-forming galaxies up to z~4
• Charting the evolution of the ages and metallicities of massive galaxies since z=0.7
• The VANDELS survey: the stellar metallicities of star-forming galaxies at 2.5 < z < 5.0
• Stellar Absorption Line Analysis of Local Star-Forming Galaxies: The Relation Between Stellar Mass, Metallicity, Dust Attenuation and Star Formation Rate
• On the Similarity between Cluster and Galactic Stellar Initial Mass Functions
• Elemental Abundances in Milky Way-like Galaxies from a Hierarchical Galaxy Formation Model
• Constraints on the star-formation rate of z~3 LBGs with measured metallicity in the CANDELS GOODS-South field
• Triggering Active Galactic Nuclei in Hierarchical Galaxy Formation: Disk instability vs. Interactions
• GMASS Ultradeep Spectroscopy of Galaxies at redshift z~2. I. The stellar metallicity
• HI-selected Galaxies in Hierarchical Models of Galaxy Formation and Evolution
• Gas accretion regulates the scatter of the mass-metallicity relation
• UV slope of z$\sim$3 bright ($L>L^{\ast }$) Lyman-break galaxies in the COSMOS field

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• The VANDELS ESO public spectroscopic survey: final Data Release of 2087 spectra and spectroscopic measurements
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• Spectroscopic observations of PHz G237.01+42.50: A galaxy protocluster at z=2.16 in the Cosmos field
• First Light And Reionisation Epoch Simulations (FLARES) VII: The Star Formation and Metal Enrichment Histories of Galaxies in the early Universe
• On the impact of spectral template uncertainties in synthetic stellar populations
• The VANDELS ESO public spectroscopic survey: The spectroscopic measurements catalogue
• The star formation history and the nature of the mass-metallicity relation of passive galaxies at 1.0<z<1.4 from VANDELS
• Observed UV continuum slopes ($\beta$) of galaxies at $z=0.40-0.75$ in the GOODS-north field