Title: Turbulence Across Cosmic Scales: From the Interstellar to Intracluster Medium
Abstract: Turbulence is ubiquitous in the universe and plays a fundamental role in shaping galaxy evolution. In this talk, I will discuss novel methods developed by my group to analyze turbulence in two vastly different astrophysical environments: the interstellar medium (ISM) and the intracluster medium (ICM). In the ISM, we use full 6-dimensional position and velocity data of young stars, obtained from the Gaia and APOGEE surveys, to probe turbulence in Milky Way star-forming regions. We compute velocity structure functions (VSFs) of these stars and find strong turbulent signatures in all diffuse stellar groups. Notably, the motions also reflect localized energy injection from supernovae in many groups and show a preference for alignment perpendicular to the local magnetic field in the Perseus molecular cloud. In the ICM, we measure turbulence using cool clouds as kinematic tracers, found both in cluster centers and in the stripped tails of jellyfish galaxies in cluster outskirts. These clouds are observed with ground-based optical and radio telescopes, providing superior spatial and spectral resolution compared to X-ray observations. In cluster centers, the clouds’ motions are directly influenced by feedback from supermassive black holes. Interestingly, the observed VSFs are significantly steeper than classical Kolmogorov predictions, posing open questions about the underlying physics. In cluster outskirts, jellyfish galaxy tails reveal turbulence driven by Kelvin-Helmholtz instabilities, with evidence for turbulent motions on scales smaller than the plasma mean free path. These results place new constraints on the effective isotropic viscosity of the ICM.