Environmental Dependence of the Mass–Metallicity Relation in Cosmological Hydrodynamical Simulations

Abstract

We investigate the environmental dependence of the gas-phase metallicity for galaxies at z = 0 to z ≳ 2 and the underlying physical mechanisms driving this dependence using state-of-the-art cosmological hydrodynamical simulations. We find that, at fixed stellar mass, central galaxies in massive halos have lower gas-phase metallicity than those in low-mass halos, while satellite galaxies residing in more massive halos are more metal-rich. The combined effect is that massive galaxies are more metal-poor in massive halos and low-mass galaxies are more metal-rich in massive halos. By inspecting the environmental dependence of other galaxy properties, we identify that the accretion of low-metallicity gas is responsible for the environmental dependence of central galaxies at high z, whereas the AGN feedback processes play a crucial role at low z. For satellite galaxies, we find that both the suppression of gas accretion and the stripping of existing gas are responsible for their environmental dependence, with negligible effect from the AGN feedback. Finally, we show that the difference of gas-phase metallicity as a function of stellar mass between protocluster and field galaxies agrees with recent observational results, for example from the MAMMOTH-Grism survey.

The MUSE Ultra Deep Field (MUDF). V. Characterizing the Mass–Metallicity Relation for Low-mass Galaxies at z ∼ 1–2

“…Specifically, satellite galaxies surrounding more massive central galaxies in groups and clusters show a small but statistically significant increase in metallicity of ∼0.1 dex (Mouhcine et al 2007;Cooper et al 2008;Ellison et al 2009;Hughes et al 2013;Kulas et al 2013;Peng & Maiolino 2014;Pilyugin et al 2017;Wang et al 2022). This enhancement is in agreement with simulations, which find comparable or larger enhancements (Wang et al 2023). This modest environmental dependence may be attributed to galaxy dynamics as satellite galaxies pass through the hot halos of their group (Maiolino & Mannucci 2019).…”

Early Results from GLASS-JWST. XXIV. The Mass–Metallicity Relation in Lensed Field Galaxies at Cosmic Noon with NIRISS*

“…In addition, all the MZRs discussed above are derived from galaxy populations residing in random fields. There has been continuous discussion about the environmental dependence of MZR shapes at high redshifts Bahé et al 2017;Calabrò et al 2022;Wang et al 2023). Here we raise one recent observation of the MZR at z ∼ 2.2 showing a much shallower slope (β = 0.14 ± 0.02), measured using the HST grism spectroscopy of 36 galaxies residing in the core of the massive BOSS1244 protocluster (Wang et al 2022b).…”

Exploring the Mpc Environment of the Quasar ULAS J1342+0928 at z = 7.54

“…We find that this quasar field is not consistent with an overdensity of LBGs, but instead with cosmic density or even an underdense region, noting that this result is heavily influenced by the limitations imposed by Poisson statistics given the sample of only one LBG candidate. This outcome is puzzling considering the recent findings of overdense quasar environments at z = 6.3 and 6.6 in Kashino et al (2023) and Wang et al (2023), respectively. The limitations show that spectroscopy might be crucial as these studies looked for galaxies emitting [O III] rather than relying on the Lyα signature.…”

“…Also, spectroscopic confirmations of galaxies (e.g., Bosman et al 2020;Mignoli et al 2020), or [C II] emitters and submillimeter galaxy searches (e.g., Decarli et al 2017;Champagne et al 2018;Meyer et al 2022) have been undertaken in the literature. Recently, leveraging the capabilities of JWST near-infrared (NIR) spectra, a substantial influx of [O III]-emitting galaxies has been unveiled in the environments of z  5 quasars (Kashino et al 2023;Wang et al 2023). Moreover, these studies encompass diverse physical areas and rely on different methods for evaluating the presence of an overdensity (e.g., Overzier 2022).…”

“…Recent studies using JWST NIRCam/WFSS spectra have demonstrated overdensities around quasars at slightly lower redshifts. Wang et al (2023) found 10 [O III] emitting galaxies in the environment of the quasar J0305-3150 at z = 6.6, probing an overdensity of galaxies in this field. Furthermore, Kashino et al (2023) compiled a comprehensive catalog of [O III] emitting galaxies at 5.3 < z < 7.0 in the field of the quasar J0100+2802 at z = 6.327.…”