Tracking the dynamical, chemical and spectral evolution of molecular cores with PrestaLine: Gorynych

Abstract

We present PrestaLine: Gorynych, a comprehensive numerical tool designed to model the dynamical, chemical, and spectral evolution of collapsing molecular cores from the prestellar phase to protostellar accretion. The code integrates three key components: (1) Kamelung, a 1D hydrodynamics module simulating gravitational collapse up to first hydrostatic core (FHSC) formation followed by an accretion of envelope onto a young star; (2) Presta, a chemical evolution module post-processing density and temperature profiles to compute time-dependent molecular abundances; and (3) Uran(IA), a radiative transfer module generating synthetic molecular line spectra. We apply Gorynych to compare low-mass (5 Msun) and high-mass (50 Msun) cores, finding that their dynamical evolution is remarkably similar, with differences primarily in spatial scaling. Chemical evolution reveals sharp abundance changes during the FHSC transition, particularly for CO, H2O, and HCO+, though pre-collapse chemical initialization has minimal impact on most species. Spectral maps of 13CO(2-1), HCO+(3-2), and H2O(110--101) lines show distinct kinematic signatures of infall and depletion, with high-mass cores exhibiting spatially extended emission. Our results highlight Gorynych's utility to couple theoretical collapse models and observations, providing a framework to diagnose core evolution and initial conditions from molecular line data.