Abstract:
To understand the build-up of stellar mass and the diversity of galaxies through cosmic times, we need to observe the neutral hydrogen (HI) - the reservoir of raw material that supplies the molecular hydrogen, from which stars directly form. Neutral hydrogen can be detected through the observations of 21cm-line, however due to its relative intrinsic faintness, such observations were mostly constrained to the local Universe (z<0.1). Next-generation facilities such as MeerKAT, allow us to push this threshold to higher redshifts. During the talk, I will present a sample of 70 galaxies with direct HI detections at redshift range of 0.22<z<0.38, observed using the MeerKAT radio telescope. To date, only 22 HI galaxies at z>0.2 have been published by three different surveys, not allowing for detailed statistical analysis. Our detections greatly enrich the number of the high-redshift sample, allowing us to determine, for the first time, the HI mass function from direct HI observations for redshifts higher than 0.2. I compare our derived HIMF to the one measured for the local Universe and the one predicted by Simba-c simulations and HI spectral stacking for higher redshifts, drawing conclusions about the baryon cycle through cosmic times.
The speaker, Michalina Maksymowicz-Maciata, is a second year PhD student at the University of Bristol, UK, where she has moved after completing an integrated masters degree at the University of Oxford. Her main research interests include galaxy evolution, dark matter and currently her PhD project mainly focuses on radio observations of neutral hydrogen in galaxies. She will give her talk in person.
Everybody is welcome to join us either in room 203 onsite, or from Zoom:
