Evolution of Virial Clouds - II: From the Formation of First Stars up to their Explosion

The existence of cold gas and dust clouds close to the cosmic microwave background (CMB) temperature was proposed as a potential repository for a significant fraction of the missing baryons in galactic halos. While the evolution of the virial clouds from the last scattering surface (LSS) (z=1100) up to the formation of Population III (Pop III) stars (z=48) was studied in [N. Tahir, A. Qadir, M. Sakhi, & F. De Paolis, The Euro. Phys. Jour. C 81, 827 (2021)] (Paper I), the subsequent evolution during the epoch of the first stars remained unexplored. In the present work, we investigate the second evolutionary phase of the virial clouds, covering the redshift range 48 z 10. We develop a comprehensive model incorporating the coupled thermal, chemical, and dynamical evolution of the cloud, including CMB heating, adiabatic compression due to gravitational contraction, H 2 and metal-line cooling, and feedback from Pop III supernovae. Solving the coupled ordinary differential equations (ODE) numerically, we find that the cloud cools monotonically from 137 K to 41.5 K, contracts from 120 pc to 89.8 pc, and becomes enriched in metals and molecular hydrogen, while the cooling rate dominates the heating rate throughout the evolution.