Rovibrational collisional rate coefficients and spectral simulations for SO with H₂

Highly accurate Molecular collisional rate coefficients are required to predict the excitation conditions, species abundances, temperature, and pressure in a variety of interstellar and extragalactic environments. Sulfur Monoxide (SO) has been widely observed in the Orion Molecular cloud, low-mass star forming regions, high-mass star-forming regions, and massive dense cores, and its collisional rate coefficients with the dominant collision partner H₂ are of astrophysical importance in modeling molecular emission in non-local thermodynamic equilibrium (NLTE) environments. In this work, we present fine-structure-resolved rovibrationally inelastic collision rate coefficients of SO with para- and ortho-H₂. The rate coefficients are computed for both rotational and rovibrational transitions of SO using quantum mechanical approaches on an accurate six-dimensional (6D) and 5D potential energy surfaces (PESs). These rovibrationally excited rate coefficients of SO with H₂ are applied in spectral simulations with the radiative transfer codes RADEX and Cloudy. We model the rovibrational emission of SO in photodissociation region (PDR) and investigate SO abundance and the physical conditions of the gas in low- and high-mass protostars. This work was partially supported by NASA Grants 80NSSC20K0360 and 80NSSC21K1464.