The masses, structure, and lifetimes of cold clouds in a high-resolution simulation of a low-metallicity starburst.

We present an analysis of the cold gas phase in a low-metallicity starburst generated in a high-resolution hydrodynamical simulation of a gas-rich dwarf galaxy merger as part of the griffin project. The simulations resolve (4 M |$_\odot$| gas phase mass resolution, |$\sim$| 0.1 pc spatial resolution) the multiphase interstellar medium with a non-equilibrium chemical heating/cooling network at temperatures below 10 |$^4$|  K. Massive stars are sampled individually and interact with the interstellar medium (ISM) through the formation of H  ii regions and supernova explosions. In the extended starburst phase, the ISM is dominated by cold (⁠|$T_\mathrm{gas} < 300$|  K) filamentary clouds with self-similar internal structures. The clouds have masses of |$10^{2.6}$| – |$10^{5.6}$|  M |$_\odot$| with a power-law mass function, |$\mathrm{ d}N/\mathrm{ d}M \propto M^\alpha$| with |$\alpha = -1.78 (\,\pm \,0.08)$|⁠. They also follow the Larson relations, in good agreement with observations. We trace the lifecycle of the cold clouds and find that they follow an exponential lifetime distribution and an e-folding time of |$\sim$| 3.5 Myr. Clouds with peak masses below |$10^4$|  M |$_\odot$| follow a power-law relation with their average lifetime |$\tau _\mathrm{life} \propto M^{0.3}_\mathrm{max}$| which flattens out for higher cloud masses at |$< 10$|  Myr. A similar relation exists between cloud size at peak mass and lifetime. This simulation of the evolution of a realistic galactic cold cloud population supports the rapid formation and disruption of star-forming clouds by stellar radiation and supernovae on a time-scale less than 10 Myr. [ABSTRACT FROM AUTHOR]