27 APRILE 2021 ore 15:00

The MeerKAT Fornax Survey first results and its prequels

Dr. Dane Kleiner (INAF - OAC, Italia)
The MeerKAT Fornax Survey first results and its prequels

I will present the first results of the MeerKAT Fornax Survey (MFS), that observes neutral hydrogen (HI) in the Fornax galaxy cluster. These are the deepest HI images to date and that provide insight into the cool gas content of the galaxies and in the intra cluster medium (ICM). The MFS is 25% complete, and strives to understand how galaxies lose their cold gas and stop forming stars in the densest regions of the cosmic web. The first MFS observations have focused on the central region of the cluster and reveal the ubiquitous presence of streams and tails of HI. I will present the implications that the new detections have on the HI mass function and how the dwarf galaxies rapidly lose their cold gas. Using MeerKAT commissioning observation of the Fornax A group, I will show that there is an abundance of evidence that the majority of group galaxies are being "pre-processed", which refers to the accelerated, non-secular evolution of galaxies that occurs prior to entering a cluster. We detect massive amounts of HI (1.12 x 10^9 Msol) in the intra group medium (IGM), which is dominated by two tidal tails (total mass 6.6 -- 11.2 x 10^8 Msol), that reach up to 220 kpc in length and were ejected from the massive, central galaxy that underwent a 10:1 merger ~ 2 Gyr ago. There are giant (~ 100 kpc) ionised hydrogen (Halpha) filaments in the IGM, where some regions also contain cool HI. We speculate that the ionised and multiphase gas is supported by magnetic pressure, shielding it from the hot halo of the central galaxy.


Breve CV del Dr. Dane Kleiner:

Dr. Kleiner received his PhD in 2017 from Monash University in Australia working with Kevin Pimbblet, Heath Jones and Baerbel Koribalski. He then spent 1 year working at CSIRO Astronomy and Space Science, doing the first science for the WALLABY project, which helped commission the Australian Square Kilometre Array Pathfinder. Since 2018, he has been working at INAF-OAC with Paolo Serra and his group, who have been driving all things related to the MeerKAT Fornax Survey. Since living in Sardinia, Dane has learned that if there's an unknown item on the menu, it's most likely cheese and he does not understand why figs on pizza is acceptable, but pineapple is not.