Jarvis, M. J.Cullen, F.McLure, R. J.2021-02-082021-02-082020Jarvis, M. J. et al. (2020). The VANDELS survey: a strong correlation between Ly α equivalent width and stellar metallicity at 3 ≤ z ≤ 5. Monthly Notices of the Royal Astronomical Society, 495(1), 1501–15101365-2966https://doi.org/10.1093/mnras/staa1260http://hdl.handle.net/10566/5860We present the results of a new study investigating the relationship between observed Ly α equivalent width (Wλ(Ly α)) and the metallicity of the ionizing stellar population ( Z⋆) for a sample of 768 star-forming galaxies at 3 ≤ z ≤ 5 drawn from the VANDELS survey. Dividing our sample into quartiles of rest-frame Wλ(Ly α) across the range −58A˚≲Wλ(Ly α) ≲110A˚⁠, we determine  Z⋆ from full spectral fitting of composite far-ultraviolet spectra and find a clear anticorrelation between Wλ(Ly α) and  Z⋆. Our results indicate that  Z⋆ decreases by a factor ≳ 3 between the lowest Wλ(Ly α) quartile (〈Wλ(Ly α)⟩=−18A˚⁠) and the highest Wλ(Ly α) quartile (〈Wλ(Ly α)⟩=24A˚⁠). Similarly, galaxies typically defined as Lyman alpha emitters (LAEs; Wλ(Ly α) >20A˚⁠) are, on average, metal poor with respect to the non-LAE galaxy population (Wλ(Ly α) ≤20A˚⁠) with  Z⋆non-LAE ≳ 2 ×  Z⋆LAE.enGalaxies: evolutionGalaxies: high-redshiftVANDELS surveyLy α equivalent widthMetallicity of the ionizing stellar populationArticle