Hydro-radiative Simulations, Analytical Modeling, and Laboratory Scaling of Complex Shock Structures in Novae Ejecta

Abstract Radiative shocks are fundamental in astrophysical phenomena, particularly in novae ejecta, where interactions between fast and slow outflows lead to double-shock structures (DSSs). However, direct observations of these shocks remain challenging due to their deep embedding within the ejecta and their small cooling layer. Hydro-radiative simulations with the RAMSES code taking radiative cooling into account are used to model the evolution of DSSs. Additionally, an analytical framework is developed to validate simulation results and predict key shock parameters. Simulations reveal significant cooling effects behind the forward shock, leading to strong density and temperature gradients. The analytical model successfully reproduces these results and enables a detailed parametric study, highlighting the influence of main parameters. Finally, using scaling laws, we miniaturize the DSS to a laboratory scale, preserving key dimensionless parameters that govern the DSS dynamics. By combining simulations, theoretical modeling, and scaling laws, this study paves the way for direct investigation of radiative shocks. It offers a unique opportunity to refine our understanding of astrophysical shock dynamics and validate current models.