The dark matter halo masses of elliptical galaxies as a function of observationally robust quantities

Sonnenfeld, Alessandro; Tortora, Crescenzo; Hoekstra, Henk; Asgari, Marika; Bilicki, Maciej; Heymans, Catherine; Hildebrandt, Hendrik; Kuijken, Konrad; Napolitano, Nicola R; Roy, Nivya; Valentijn, Edwin; Wright, Angus H

Abstract

Context. The assembly history of the stellar component of a massive elliptical galaxy is closely related to that of its dark matter halo. Measuring how the properties of galaxies correlate with their halo mass can therefore help to understand their evolution. Aims. We investigate how the dark matter halo mass of elliptical galaxies varies as a function of their properties, using weak gravi-tational lensing observations. To minimise the chances of biases, we focus on the following galaxy properties that can be determined robustly: the surface brightness profile and the colour. Methods. We selected 2409 central massive elliptical galaxies (log M * /M 11.4) from the Sloan Digital Sky Survey spectroscopic sample. We first measured their surface brightness profile and colours by fitting Sérsic models to photometric data from the Kilo-Degree Survey (KiDS). We fitted their halo mass distribution as a function of redshift, rest-frame r−band luminosity, half-light radius, and rest-frame u − g colour, using KiDS weak lensing measurements and a Bayesian hierarchical approach. For the sake of robustness with respect to assumptions on the large-radii behaviour of the surface brightness, we repeated the analysis replacing the total luminosity and half-light radius with the luminosity within a 10 kpc aperture, L r,10 , and the light-weighted surface brightness slope, Γ 10. Results. We did not detect any correlation between the halo mass and either the half-light radius or colour at fixed redshift and luminosity. Using the robust surface brightness parameterisation, we found that the halo mass correlates weakly with L r,10 and anti-correlates with Γ 10. At fixed redshift, L r,10 and Γ 10 , the difference in the average halo mass between galaxies at the 84th percentile and 16th percentile of the colour distribution is 0.00 ± 0.11 dex. Conclusions. Our results indicate that the average star formation efficiency of massive elliptical galaxies has little dependence on their final size or colour. This suggests that the origin of the diversity in the size and colour distribution of these objects lies with properties other than the halo mass.

Citation

Sonnenfeld, A., Tortora, C., Hoekstra, H., Asgari, M., Bilicki, M., Heymans, C., …Wright, A. H. (in press). The dark matter halo masses of elliptical galaxies as a function of observationally robust quantities. Astronomy and Astrophysics, https://doi.org/10.1051/0004-6361/202142511

• Journal Article Type: Article
• Acceptance Date: Mar 28, 2022
• Online Publication Date: Apr 13, 2022
• Deposit Date: Apr 19, 2022
• Publicly Available Date: Apr 20, 2022
• Journal: Astronomy and Astrophysics
• Print ISSN: 0004-6361
• Publisher: EDP Sciences
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1051/0004-6361/202142511
• Public URL: https://hull-repository.worktribe.com/output/3980063