KiDS-DR5: Exploring dust transport in dark matter halos of galaxies

Abstract

We analyse a well-defined sample of galaxies from the final data release of the Kilo-Degree Survey (KiDS-DR5), selected using magnitude, photometric redshift, and stellar mass cuts, to measure their mean halo mass and circumgalactic dust content as a function of stellar mass. Our goal is to provide empirical constraints on dust transport mechanisms, such as stellar- and AGN-driven outflows, operating in galaxy halos. We develop and validate a new measurement and modelling framework using the MICE2 simulation, incorporating a realistic circumgalactic dust extinction scenario. Using this framework, we jointly model multiband ($ugriZYJH{K}_{\mathrm{s}}$) magnitude shifts and galaxy--galaxy lensing signals to infer the mean halo mass and dust mass of lens galaxies at $z_{\mathrm{B}}<0.4$, analysed in five stellar-mass bins in KiDS-DR5. The modelling jointly describes the halo mass distribution and dust extinction, including dust associated with neighbouring halos. We demonstrate that the inclusion of a satellite fraction and dust extinction from neighbouring halos is required by the data. We find a linear relation between stellar mass and dust mass, consistent with previous observational studies, but flatter than predictions from the semi-analytic model \textsc{Dusty-SAGE}. This difference may indicate that current implementations of dust-related feedback in galaxy formation models require further refinement.

arXiv comment17 pages, 13 figures, submitted to A&A