Bulge+disc decomposition of HFF and CANDELS galaxies: UVJ diagrams and stellar mass-size relations of galaxy components at 0.2 ≤ z ≤ 1.5

August 2024 • 2024MNRAS.532.3747N

Authors • Nedkova, Kalina V. • Häußler, Boris • Marchesini, Danilo • Brammer, Gabriel B. • Feinstein, Adina D. • Johnston, Evelyn J. • Kartaltepe, Jeyhan S. • Koekemoer, Anton M. • Martis, Nicholas S. • Muzzin, Adam • Rafelski, Marc • Shipley, Heath V. • Skelton, Rosalind E. • Stefanon, Mauro • van der Wel, Arjen • Whitaker, Katherine E.

Abstract • Using deep imaging from the CANDELS and HFF surveys, we present bulge+disc decompositions with GALFITM for $\sim$17 000 galaxies over $0.2 \le z\le 1.5$. We use various model parameters to select reliable samples of discs and bulges, and derive their stellar masses using an empirically calibrated relation between mass-to-light ratio and colour. Across our entire redshift range, we show that discs follow stellar mass-size relations that are consistent with those of star-forming galaxies, suggesting that discs primarily evolve via star formation. In contrast, the stellar mass-size relations of bulges are mass-independent. Our novel data set further enables us to separate components into star-forming and quiescent based on their specific star formation rates. We find that both star-forming discs and star-forming bulges lie on stellar mass-size relations that are similar to those of star-forming galaxies, while quiescent discs are typically smaller than star-forming discs and lie on steeper relations, implying distinct evolutionary mechanisms. Similar to quiescent galaxies, quiescent bulges show a flattening in the stellar mass-size relation at $\sim 10^{10}$ M$_\odot$, below which they show little mass dependence. However, their best-fitting relations have lower normalizations, indicating that at a given mass, bulges are smaller than quiescent galaxies. Finally, we obtain rest-frame colours for individual components, showing that bulges typically have redder colours than discs, as expected. We visually derive UVJ criteria to separate star-forming and quiescent components and show that this separation agrees well with component colour. HFF bulge+disc decomposition catalogues used for these analyses are publicly released with this paper.

Links

• PREPRINT http://arxiv.org/abs/2406.14613
• NED https://ned.ipac.caltech.edu/uri/NED::InRefcode/2024MNRAS.532.3747N
• ELECTR https://doi.org/10.1093%2Fmnras%2Fstae1702
• SIMBAD https://simbad.u-strasbg.fr/simbad/sim-ref?querymethod=bib&simbo=on&submit=submit+bibcode&bibcode=2024MNRAS.532.3747N
• PDF https://academic.oup.com/mnras/pdf-lookup/doi/10.1093/mnras/stae1702
• DATA https://archive.stsci.edu/mastbibref.php?bibcode=2024MNRAS.532.3747N
• DATA https://hst.esac.esa.int/ehst/#/pages/search;bibcode=2024MNRAS.532.3747N