Abstract
| Ditrani |
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| Stellar metallicity in galaxies: a novel promising approach based on UV indices |
| We recently investigated the capability to retrieve the stellar metallicity in galaxies at different SNR in the redshift range 0.3 < z < 0.7. Our analysis is based on a rich template library and simulations mimicking observed galaxy spectra for the forthcoming WEAVE-StePS project (Iovino et al. 2023). WEAVE-StePS novelty is that it will provide spectra including both ultraviolet and optical rest-frame absorption-line indices for intermediate redshift galaxies. Our main result is that metallicity estimates can be obtained even in case of modest SNR spectra (i.e., ~ 10/Å) if considering a wider and bluer spectral window (3500-5300 Å) with respect of using only the classical optical indices (4800-5300 Å) which require SNR twice as high. We found that stellar metallicity can be derived with an accuracy better than 0.3 dex with WEAVE-StePS-like data in particular for stellar populations older than 2 Gyr (Ditrani et al. 2023). This result is very promising for future higher-redshift surveys, given that the use of bluer spectral indices offers the further advantage of avoiding observed wavelength regions that are strongly affected by atmospheric contamination. We will present a first test case based on spectroscopic observations of a large filamentary structure at z ~ 0.73, named COSMOS Wall. This structure encompasses a comprehensive range of environments, from dense clusters to adjacent voids, enabling investigation of the relation between stellar metallicity and the environment. |