| Name: Meera Nandakumar |
| Affiliation: University of Cape Town, South Africa |
| Conference ID: ASI2026_134 |
| Title: What Drives Turbulence in Galactic Discs? Evidence from MeerKAT HI Observations |
| Abstract Type: Oral |
| Abstract Category: Galaxies and Cosmology |
| Author(s) and Co-Author(s) with Affiliation: Meera Nandakumar(University of Cape Town, Cape Town - 7700, South Africa), D J Pisano(University of Cape Town, Cape Town - 7700, South Africa), Prasun Dutta(Indian Institute of Technology (IIT-BHU), Varanasi - 221005, India), W.J.G. de Blok(ASTRON, the Netherlands Institute for Radio Astronomy, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, the Netherlands), Sushma Kurapati(National Centre for Radio Astrophysics,Pune - 411007, INDIA), Kyra Kummer(University of Cape Town, Cape Town - 7700, South Africa) |
| Abstract: The interstellar medium (ISM) behaves as a compressible, turbulent fluid, producing scale-invariant density and velocity fluctuations. These turbulent structures regulate star formation by promoting gravitational collapse and contributing to pressure support. While statistical properties such as the density power spectrum and velocity dispersion are established in a few galaxies, their dynamical correlations and driving mechanisms remain unclear.
Successful measurements of the HI column density and line-of-sight velocity power spectra using the Visibility Moment Power Spectrum Estimator (VME) in a few spiral galaxies reveal a diversity in the mechanisms driving large-scale turbulence. Expanding on these studies, we use high-sensitivity MeerKAT HI observations of galaxies that are part of the large surveys MHONGOOSE and PHANGS-HI to quantify ISM turbulence. The galaxy sample spans a wide range of morphologies, star formation activities, and environmental conditions, enabling a systematic investigation of how ISM turbulence depends on overall galactic evolution and dynamics. I will present our results and discuss how they contribute to establishing a unified picture of turbulence dynamics in the ISM, focusing on the nature, origin, and implications of these structures on star formation and galactic evolution. |
