Café-Club

Georg HERZOG (Università di Milano “Bicocca”): “The present-day gas content of simulated field dwarf galaxies”.

The cafe-club will take place at 11:00 am in the Library at LAM and on usual AMU virtual room:
(Meeting ID : 968 7683 2544 — Passcode : 173347, not needed if using the link above)
You can find the schedule of upcoming café-clubs and the video of old ones here

Take care,
Carlo, Meriam, Mathilde

—————-
ABSTRACT

It is known from theory and observations that galaxy evolution can be influenced by environmental effects. Processes like ram pressure stripping in groups, clusters or the cosmic web as well as tidal stripping can affect the final properties of galaxies. However, until now no estimate exists on the relative importance of different processes for the final properties of field galaxies. Based on a high-resolution cosmological simulation I will show that there are two distinct processes that affect the present-day gas content of field dwarf galaxies. 1) Past interactions with massive hosts, in which a dwarf loses gas and dark matter via tidal and ram-pressure forces; and 2) hydrodynamic interactions with the gaseous filaments and sheets of the cosmic web, in which a dwarf loses gas via ram-pressure. I will refer to these galaxies as “flybys” and “COSWEBs”, respectively. While flybys are located in high-density regions, tracing the location of the most massive galaxies in the simulation, COSWEBs are dispersed throughout the volume and trace the cosmic web. For dwarf galaxies with M_200 < 5*10^9 Msun the fraction of COSWEBs can be as high as 35%, while flybys make up 100% of galaxies with M_200 < 3*10^8 Msun. The deficit of gas of flyby and COSWEB galaxies can preclude the detection of a large fraction of field dwarfs in future HI surveys.