Speaker
Description
Most galaxies do not evolve in isolation. Their properties are impacted by their environment. Galaxy clusters are the most massive, densest, gravitationally bound structures in the universe comprised of thousands of galaxies contained within a region of a few cubic megaparsecs. In this environment, galaxies have frequent, high-speed interactions that disrupt their outer disks. Further, as they move through the hot, intracluster medium (ICM) their gas is removed through a process called ram pressure stripping. The Fornax cluster is the most massive galaxy cluster within 20 Mpc in the southern hemisphere and so is an ideal target for studying the effect of the cluster environment on galaxies. The MeerKAT Fornax Survey (MFS) is currently mapping the HI in the cluster over 12 square degrees down to an HI column density of 10^18 atoms per
square centimetre in an attempt to detect the diffuse HI in the cluster, as well as to study the effect of the cluster environment on galaxies.
To complement the MFS, we have observed a portion of the Fornax cluster with the Green Bank Telescope (GBT) down to a similar HI column density. The GBT observations are well-suited for detecting extended, diffuse HI emission. When combined with the MeerKAT observations, we will have a more complete understanding of the HI distribution in the Fornax cluster down to faint levels of emission.
Due to MeerKAT’s advanced observational capabilities, we are able to conduct comparisons with numerical modelling of cluster environments. The TNG50 cosmological simulations have produced HI maps of Fornax-like cluster halos (A Fornax-like halo is defined as that mass enclosed within a sphere of radius R200, where R200 is defined as the radius within which the average density is 200 times the critical density of the universe) that predict to find extended HI well beyond the satellites in the halo.
The comparison will serve as a test of the TNG50 cosmological simulations.
| Stream | Science |
|---|