I completed six months of coursework and a one-and-a-half-year M.Sc. dissertation at the University of Cape Town. The M.Sc. program began in 2008, and I was conferred my degree in June 2011. The coursework covered the following subjects:
For my dissertation, we used the neutral atomic hydrogen line (HI) in nearby galaxies as a tracer to investigate the phase structure of the interstellar medium (ISM) and its relationship with galaxy properties and morphology. To create high signal-to-noise (S/N) profiles, we applied a method similar to the stacking method often used in high-redshift HI observations. These high S/N profiles are referred to as “super profiles”.
By decomposing the super profiles into Gaussian components, we observed the presence of broad and narrow components across all analyzed galaxies. In line with previous research, we identified the narrow and broad components as representations of the Cold Neutral Medium (CNM) and Warm Neutral Medium (WNM) phases of the ISM, respectively. Additionally, we created radial super profiles for several galaxies from The HI Nearby Galaxy Survey and discovered correlations between the shapes of the profiles and their positions within the galaxies.
Our analysis revealed a radial decline in HI velocity dispersions for most of the sample galaxies. We also found that the narrow component was dominant within the optical radius \((r_{25})\) of the galaxies. The super profiles displayed broader and more asymmetric characteristics inside \((r_{25})\). Further examination of super profiles within different star formation regions revealed that the profiles tend to be broader and more asymmetric in areas of active star formation. Moreover, the narrow component was observed to be dominant in regions with higher star formation rates.
I obtained my Ph.D. in Astronomy in June 2014, at the University of Cape Town (UCT), under the general guidance of Prof. W. J. G. de Blok. The thesis title was "Interstellar medium properties and star formation in nearby galaxies". My thesis received an A rating from all three external examiners. My subsequent peer-reviewed papers have been valuable for theoretical models that assess the role and origin of turbulence in the interstellar medium.
The thesis made use of high-resolution interferometric observations of neutral atomic hydrogen (HI) gas in nearby galaxies to measure with high precision fundamental parameters, relevant for star formation studies. I achieved this robust measurement by reducing the effects of noise using a spectral-line stacking technique.
The University of Cape Town (UCT)
After my Ph.D., I worked as a postdoctoral fellow at the University of South Africa (UNISA). There I continued my research on HI observations of nearby galaxies, focusing on the morphological and radial dependence of the HI line widths. Together with international collaborators, I also worked on similar research topics, involving a comparative study of HI versus carbon-monoxide (CO) line widths. These papers have received notable citations, particularly from studies of the physics of star formation.
After receiving funding from the Alexander von Humboldt Foundation, I pursued a two-year postdoctoral fellowship at the Max Planck Institute for Astronomy (MPIA), working with Dr. Fabian Walter's research group. My research focused on two main projects: analyzing systematic effects during image reconstruction on HI velocity profiles and developing a new stacking technique to detect faint HI emissions at the outer disks of nearby galaxies.
After my time at MPIA, I returned to South Africa as a postdoctoral fellow at the Centre for Radio Astronomy Techniques and Technologies (RATT) at Rhodes University, working with Prof. Oleg Smirnov's group. I became heavily involved in HI science with MeerKAT, leading two successful proposals.
One project, "A Search For Diffuse HI Emission In The Nearby Dwarf Irregular Galaxy WLM and IC 1613", aimed to model the HI morphologies and kinematics to search for signs of gas accretion. The second project, "Mapping the starburst galaxy NGC 4945 with MeerKAT-64", sought to map the extended HI disk and radio continuum emission to study the interplay between gas and star formation.
Currently, I am a postdoctoral fellow at the Instituto de Astrofísica de Andalucía - CSIC (IAA-CSIC), Granada, Spain, working under the leadership of Dr. Lourdes Verdes-Montenegro. My research focuses on the lifecycle of gas in galaxy groups, analyzing MeerKAT HI data of the Hickson Compact Groups. I aim to investigate the connection between star formation and gas removal in these groups and to separate intra-group gas from galaxy gas through kinematic modelling.
