Astrochemistry is an interdependent triangle comprised of observation, modeling, and the generation of reference data. (This last branch is often called "laboratory astrophysics".)
Each point on the triangle fundamentally needs the other. While some would argue that all astrochemistry ultimately exists to feed observation, this pillar cannot stand on its own.
Observation requires reference points for both the spectral features to be observed telescopically and also requires estimates for the abundance or column density of the material in the regions toward which the observation is taking place.
Modeling, in the context of chemical reaction modeling, requires input from observation to know what molecules may be present to include in the models but also requires input from reference data to provide details about reactants, products, relative energies, collision rates, photochemical data, and reaction rate constants (among other considerations).
Generation of reference data, for the third pillar, requires the same input from observation as the modeling does and also is fed from the types of observables that are modeled.
Hence, the triangle is completely interrelated. While some add the fourth pillar of astrochemistry as instrument development, this could be construed as a hybrid of the observation and laboratory work to generate the valuable instruments for both observation and laboratory experimentation to function.
Each of these pillars on the triangle can be further split into subdisciplines.
Observation is readily separated into observational wavelength regimes with radioastronomy serving as the primary detection medium for the past 70 years. However, with the launch of the James Webb Space Telescope (JWST), infrared (IR) is growing in significance.
Reference generation could be split into spectroscopy, reaction behavior, molecular property generation, etc. However, reference generation does not have to come from the laboratory alone, hence a different moniker used herein besides "laboratory astrophysics." Where else could such reference data be generated if not the lab? Quantum chemistry stand outs.
