Oral Presentation

Modelling galaxy quenching and spatial distributions of star-forming and quenched galaxies

Author(s): Taira Oogi, Naoki Yoshida, Takahiro Nishimichi, Chiaki Hikage (Kavli IPMU)

Presenter: Taira Oogi (Kavli IPMU)

We examine the origin of halo-centric gradients of star-forming activities of group and cluster galaxies with an empirical model.
We perform the subhalo abundance matching and a variation of age matching prescription to connect galaxy stellar mass and specific star formation rate with dark matter (sub)haloes extracted from a cosmological $N$-body simulation.
In the model, for subhaloes we take both the halo formation time and the accretion time when a subhalo fall into a larger halo into account as a proxy of the quenching epoch of satellite star formation.
Our result can reproduce the large-sale clustering of star-forming and quenched galaxies as seen in previous work.
We demonstrate that the model can reproduce the observed quenched fraction in galaxy groups and clusters as a function of halo mass, stellar mass, and halo-centric distance.
These results indicate that the radial gradient of the quenched fraction can provide unique insight into the quenching process in galaxy groups and clusters.
Our results also indicate that the radial gradient of the quenched fraction is a key constraint on the models for the relationship between a halo and the SSFR of the galaxy it hosts.