OPTIMus-Survey of massive star-forming regions at OPTical, Infrared, and Millimeter wavelengths

This work presents a description of the scientific goals and objectives of OPTIMus (OPTical, Infrared, Millimeter survey of massive star-forming regions), a survey of massive star-forming regions in the optical, infrared, and millimeter wavelengths. The survey is aimed at constructing a comprehensive characterization of the multicomponent and structurally complex interstellar medium in the vicinity of young massive stars, combining both observational and theoretical aspects. Using multi-wavelength observational data, we will reconstruct the three-dimensional structure and determine the physical parameters of HII regions, photodissociation regions, and the surrounding molecular clouds. The paper describes the observational data obtained with the BTA 6-m and Zeiss-1000 telescopes of the Special Astrophysical Observatory of the Russian Academy of Sciences, the 2.5-m telescope of the Caucasian Mountain Observatory of the Sternberg Astronomical Institute of Moscow State University, and the 20-m telescope of the Onsala Space Observatory.