Intrinsic and Environmental Effects on the Distribution of Star Formation in TNG100 Galaxies

TL;DR

This study uses TNG100 simulations to analyze how intrinsic properties and environment influence the radial distribution of star formation and quenching in galaxies, revealing different dominant processes based on galaxy mass.

Contribution

It provides a detailed analysis of the effects of intrinsic and environmental factors on star formation profiles in galaxies, highlighting the roles of AGN feedback and environment across different mass regimes.

Findings

High-mass galaxies show inside-out quenching driven by AGN feedback.

Environmental effects are significant only at extreme halo masses and overdensities.

Low-mass galaxies are primarily quenched by environmental processes, outside-in.

Abstract

We present radial profiles of luminosity-weighted age, $age_L$, and $\Delta \Sigma_{SFR}$ for various populations of high- and low- mass central and satellite galaxies in the TNG100 cosmological simulation. Using these profiles, we investigate the impact of intrinsic and environmental factors on the radial distribution of star formation. For both central galaxies and satellites, we investigate the effects of black hole mass, cumulative AGN feedback energy, morphology, halo mass, and local galaxy overdensity on the profiles. In addition, we investigate the dependence of radial profiles of the satellite galaxies as a function of the redshifts at which they joined their hosts, as well as the net change in star-forming gas mass since the satellites joined their host. We find that high-mass ($M_*>10^{10.5} M_{\odot}$) central and satellite galaxies show evidence of inside-out quenching driven by AGN feedback. Effects from environmental processes only become apparent in averaged profiles at extreme halo masses and local overdensities. We find that the dominant quenching process for low-mass galaxies ($M_*<10^{10} M_{\odot}$) is environmental, generally occurring at low halo mass and high local galaxy overdensity for low-mass central galaxies and at high host halo masses for low-mass satellite galaxies. Overall, we find that environmental processes generally drive quenching from the outside-in.