2025-05-27 –, Main Conference Room
The interaction of massive stars with their environments regulates the evolution of galaxies. Specifically, through their radiation and their winds, massive stars disrupt their environment and disturb their nascent molecular cloud.
The combination of the sensitive THz heterodyne receiver arrays upGREAT with a nimble telescope on SOFIA enabled large-scale [CII] 158 μm surveys of regions of massive star formation. This line is the main cooling line of neutral gas in the interstellar medium and therefore a key diagnostic of the interstellar gas energy balance. It also provides a unique window on stellar feedback. The high spectral resolution inherent to heterodyne techniques allows a detailed study of the kinematics of photodissociation regions, which separate ionized from molecular gas.
Comparing and contrasting three regions with different types of stellar feedback allows to identify universal and environment-specific features of stellar feedback: The Horsehead Nebula in the Orion B molecular cloud is being compressed and evaporated by a previously-formed nearby massive star (Bally et al. 2018), while the Orion Nebula, the closest region of massive star formation, situated in the Orion A molecular cloud, contains multiple nested expanding shells being blown by a single massive star in its core. 30 Doradus in the LMC, on the other hand, is the nearest birth site of a super star cluster, where ~1000 OB stars are disrupting the molecular cloud in which they were formed. The [CII]-emitting structures in Orion can be studied in large spatial detail, while in 30 Doradus, a significant amount of the input mechanic and radiative energy is dissipated on scales smaller than 14” (3.4 pc at a distance of 50 kpc), the resolution of SOFIA at 158 μm, as has previously been suggested by observations of the ionized gas. This renders the lines broader than expected from observations of Orion. In my talk I will review differences and similarities in these regions.
