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We present observational evidence for a stellar fundamental metallicity relation (FMR), a smooth relation between stellar mass, star formation rate, and the light-weighted stellar metallicity of galaxies, analogous to the well-established gas-phase FMR. We use the non-parametric software ppxf to reconstruct simultaneously the star formation and chemical-enrichment history of a representative sample of galaxies from the local MaNGA (Mapping Nearby Galaxies at Apache Point Observatory) survey. We find that (i) the metallicity of individual galaxies increases with cosmic time and (ii) at all stellar masses, the metallicity of galaxies is progressively higher, moving from the starburst region above the main sequence (MS) towards the passive galaxies below the MS, manifesting the stellar FMR. The scatter is reduced when replacing the stellar mass |$M_{*}$| with |$M_{*}/R_{\rm e}$| (with |$R_{\rm e}$| being the effective radius), in agreement with previous results using the velocity dispersion |$\sigma _{\rm e}$|⁠ , which correlates with |$M_{*}/R_{\rm e}$|⁠. Our results point to starvation as the main physical process through which galaxies quench, showing that metal-poor gas accretion from the intergalactic medium/circumgalactic medium – or the lack thereof – plays an important role in galaxy evolution by simultaneously shaping both their star formation and their metallicity evolutions, while outflows play a subordinate role. This interpretation is further supported by the additional finding of a young stellar FMR, tracing only the stellar populations formed in the last 300 Myr. This suggests a tight co-evolution of the chemical composition of both the gaseous interstellar medium and the stellar populations, where the gas-phase FMR is continuously imprinted on to the stars over cosmic times. [ABSTRACT FROM AUTHOR]

We present an analysis of the quenching of local observed and simulated galaxies, including an investigation of the dependence of quiescence on both intrinsic and environmental parameters. We apply an advanced machine learning technique utilizing random forest classification to predict when galaxies are star forming or quenched. We perform separate classification analyses for three groups of galaxies: (a) central galaxies, (b) high-mass satellites (⁠|$M_{*} \gt 10^{10.5}\,{\rm {\rm M}_{\odot }}$|⁠), and (c) low-mass satellites (⁠|$M_{*} \lt 10^{10}\,{\rm {\rm M}_{\odot }}$|⁠) for three cosmological hydrodynamical simulations (Evolution and Assembly of GaLaxies and their Environments, Illustris, and IllustrisTNG), and observational data from the Sloan Digital Sky Survey. The simulation results are unanimous and unambiguous: quiescence in centrals and high-mass satellites is best predicted by intrinsic parameters (specifically central black hole mass), while it is best predicted by environmental parameters (specifically halo mass) for low-mass satellites. In observations, we find black hole mass to best predict quiescence for centrals and high-mass satellites, exactly as predicted by the simulations. However, local galaxy overdensity is found to be most predictive parameter for low-mass satellites. None the less, both simulations and observations do agree that it is environment which quenches low-mass satellites. We provide evidence which suggests that the dominance of local overdensity in classifying low-mass systems may be due to the high uncertainty in halo mass estimation from abundance matching, rather than it being fundamentally a more predictive parameter. Finally, we establish that the qualitative trends with environment predicted in simulations are recoverable in the observation space. This has important implications for future wide-field galaxy surveys. [ABSTRACT FROM AUTHOR]

We present the first study of spatially integrated higher-order stellar kinematics over cosmic time. We use deep rest-frame optical spectroscopy of quiescent galaxies at redshifts z  = 0.05, 0.3, and 0.8 from the SAMI, MAGPI, and LEGA-C surveys to measure the excess kurtosis h 4 of the stellar velocity distribution, the latter parametrized as a Gauss-Hermite series. Conservatively using a redshift-independent cut in stellar mass (⁠|$M_\star = 10^{11}\, \mathrm{M_\odot }$|⁠) and matching the stellar-mass distributions of our samples, we find 7σ evidence of h 4 increasing with cosmic time, from a median value of 0.019 ± 0.002 at z  = 0.8 to 0.059 ± 0.004 at z  = 0.06. Alternatively, we use a physically motivated sample selection based on the mass distribution of the progenitors of local quiescent galaxies as inferred from numerical simulations; in this case, we find 10σ evidence. This evolution suggests that, over the last 7 Gyr, there has been a gradual decrease in the rotation-to-dispersion ratio and an increase in the radial anisotropy of the stellar velocity distribution, qualitatively consistent with accretion of gas-poor satellites. These findings demonstrate that massive galaxies continue to accrete mass and increase their dispersion support after becoming quiescent. [ABSTRACT FROM AUTHOR]

The article titled "Correction to: The role of environment and AGN feedback in quenching local galaxies: comparing cosmological hydrodynamical simulations to the SDSS" by Goubert et al. has been published in the Monthly Notices of the Royal Astronomical Society. The study included an error in the calculation of nearest neighbor densities, which has now been corrected. The main results and conclusions of the publication remain unchanged, except for figure 16. The corrected pre-selection criteria and an updated version of the figure are presented in this erratum. The difference in density parameters between observations and simulations can be explained by the lower completeness of the data obtained from the SDSS. The fundamental conclusions regarding which galaxies quench via intrinsic and environmental routes remain the same. [Extracted from the article]

We investigate how star formation quenching proceeds within central and satellite galaxies using spatially resolved spectroscopy from the SDSS-IV MaNGA DR15. We adopt a complete sample of star formation rate surface densities (ΣSFR), derived in Bluck et al. (2020), to compute the distance at which each spaxel resides from the resolved star forming main sequence (ΣSFR − Σ* relation): ΔΣSFR. We study galaxy radial profiles in ΔΣSFR, and luminosity weighted stellar age (AgeL), split by a variety of intrinsic and environmental parameters. Via several statistical analyses, we establish that the quenching of central galaxies is governed by intrinsic parameters, with central velocity dispersion (σc) being the most important single parameter. High mass satellites quench in a very similar manner to centrals. Conversely, low mass satellite quenching is governed primarily by environmental parameters, with local galaxy overdensity (δ5) being the most important single parameter. Utilizing the empirical M BH − σc relation, we estimate that quenching via AGN feedback must occur at |$M_{\rm BH} \ge 10^{6.5-7.5} \, \mathrm{M}_{\odot }$|⁠ , and is marked by steeply rising ΔΣSFR radial profiles in the green valley, indicating 'inside-out' quenching. On the other hand, environmental quenching occurs at overdensities of 10–30 times the average galaxy density at z ∼ 0.1, and is marked by steeply declining ΔΣSFR profiles, indicating 'outside-in' quenching. Finally, through an analysis of stellar metallicities, we conclude that both intrinsic and environmental quenching must incorporate significant starvation of gas supply. [ABSTRACT FROM AUTHOR]

We present an analysis of star formation and quenching in the SDSS-IV MaNGA-DR15, utilizing over 5 million spaxels from ∼3500 local galaxies. We estimate star formation rate surface densities (ΣSFR) via dust corrected H α flux where possible, and via an empirical relationship between specific star formation rate (sSFR) and the strength of the 4000 Å break (D4000) in all other cases. We train a multilayered artificial neural network (ANN) and a random forest (RF) to classify spaxels into 'star-forming' and 'quenched' categories given various individual (and groups of) parameters. We find that global parameters (pertaining to the galaxy as a whole) perform collectively the best at predicting when spaxels will be quenched, and are substantially superior to local/spatially resolved and environmental parameters. Central velocity dispersion is the best single parameter for predicting quenching in central galaxies. We interpret this observational fact as a probable consequence of the total integrated energy from active galactic neucleus (AGN) feedback being traced by the mass of the black hole, which is well known to correlate strongly with central velocity dispersion. Additionally, we train both an ANN and RF to estimate ΣSFR values directly via regression in star-forming regions. Local/spatially resolved parameters are collectively the most predictive at estimating ΣSFR in these analyses, with stellar mass surface density at the spaxel location (Σ*) being by far the best single parameter. Thus, quenching is fundamentally a global process but star formation is governed locally by processes within each spaxel. [ABSTRACT FROM AUTHOR]