2025/07/28 by George, Ashwin Vergis, Das, Hitesh Kishore, Gronke, Max
#Astrophysics of Galaxies (astro-ph.GA) #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences
paper · doi:10.48550/arxiv.2507.20962
Cold gas clouds embedded in a hot, turbulent medium are expected to be short-lived due to disruptive hydrodynamic instabilities. However, radiative cooling might allow such clouds to survive and grow. We present 3D Athena++ simulations of clouds with a density contrast of χ= 1000, exploring turbulent Mach numbers M∈ (0.25, 0.75) and cloud radii chosen to span cooling-to-crushing ratios α∈ [0.001, 10]. We find a shift in the survival boundary, with cloud survival occurring only when the cooling-to-cloud-crushing ratio (tcool,mix / tcc) \lesssim 0.01, which is lower than the expected boundary of ∼ 1. This result shows that it is more difficult for higher over-density cold clouds to survive in a turbulent, hot medium, and suggests another `survival criterion'.