Abstract
The Orion molecular cloud (OMC) complex is the nearest and perhaps the best-studied giant molecular cloud complex within which low-mass and massive star formation occur. A variety of molecular species, from diatomic molecules to complex organic molecules (COMs), have been observed in the OMC regions. Different chemical species are found at different scales—from giant molecular clouds at parsec scales to cloud cores around young stellar objects at hundreds of au scales, and they act as tracers of different physical and chemical conditions of the sources. The OMC, therefore, is an ideal laboratory for studying astrochemistry over a broad spectrum of molecular cloud structures and masses. In this review, we discuss the usage of astrochemistry/molecular tracers and (sub) millimeter observations to understand the physical and chemical conditions of large-scale molecular clouds, filaments, and clumps down to cores and protostars in the OMC complex as a demonstration case.
Highlights
The Orion molecular cloud (OMC) complex is a vast region consisting of giant molecular clouds (GMCs) with a variety of physical conditions
Emission from certain molecular species is useful in understanding the physical conditions; these species are often called “tracers.” The emission from molecular species depends on the local excitation conditions and the chemical formation mechanism in interstellar medium (ISM) environments
In addition to the OB clusters and high mass star-forming regions such as NGC 1977, FIGURE 2 | (A): The combined map of OMCs based on IRAS 25.60, 100 μm observations and CO map from Dame et al (2001)
Summary
The Orion molecular cloud (OMC) complex is a vast region consisting of giant molecular clouds (GMCs) with a variety of physical conditions It is named after the “Orion” constellation, and the term “complex” is the collective name indicating different kinds of astronomical environments residing within. We recently performed survey observations toward the Orion molecular cores using ALMA at a resolution ∼ 120 au (Dutta et al, 2020; Hsu et al, 2020; Sahu et al, 2021) These sources were earlier studied using the single-dish James Clerk Maxwell Telescope (JCMT). These consecutive observations help us understand physical and chemical evolution from large-scale core and clumps down to protostars. These observations enable us to understand the chemical evolution from GMCs down to protostars
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
