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arXiv · 2512.19310

Galaxy And Mass Assembly (GAMA): Deconstructing the galaxy stellar mass function by star formation and environment

A. Sbaffoni·J. Liske·A. S. G. Robotham·L. J. M. Davies·S. P. Driver·E. N. Taylor
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Abstract

Using the equatorial Galaxy and Mass Assembly (GAMA) dataset, we investigate how the low-redshift galaxy stellar mass function (GSMF) varies across different galaxy populations and as a function of halo mass. We find that: (i) The GSMF of passive and star-forming galaxies are well described by a double and a single Schechter function, respectively, although the inclusion of a second component for the star-forming population yields a more accurate description. Furthermore, star-forming galaxies dominate the low-mass end of the total GSMF, whereas passive galaxies mainly shape the intermediate-to-high-mass regime. (ii) The GSMF of central galaxies dominates the high-mass end, whereas satellites and ungrouped galaxies shape the intermediate-to-low-mass regime. Additionally, we find a relative increase in the abundance of low-mass galaxies moving from dense group environments to isolated systems. (iii) More massive halos host more massive galaxies, have a higher fraction of passive systems, and show a steeper decline in the number of intermediate-mass galaxies. Finally, our results reveal larger differences between passive and star-forming GSMFs than predicted by a phenomenological quenching model, but generally confirm the environmental quenching trends for centrals and satellites reported in other works.

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A. Sbaffoni, J. Liske, A. S. G. Robotham, L. J. M. Davies, S. P. Driver, E. N. Taylor. 2025-12-22. Galaxy And Mass Assembly (GAMA): Deconstructing the galaxy stellar mass function by star formation and environment. https://doi.org/10.1051/0004-6361/202557424

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