Presentation #406.17 in the session Young Stellar Objects and T Tauri Stars — iPoster Session.
The physical processes involved in massive star formation are still not well understood. Our understanding of the stages involved in forming massive stars, as well as their environments, is inhibited in part due to the high extinction in star-forming regions, but also because massive stars have shorter lifetimes and are rarer than low mass stars. Studying the chemistry and formation of complex molecules in these environments may also offer insights into the processes involved in star and planet formation. We aim to address such challenging aspects of massive star formation by using high spectral resolution observations of CO gas obtained by iSHELL (R = 80,000) on the NASA Infrared Telescope Facility (IRTF) around the massive young binary Mon R2 IRS3 to determine the physical structure, such as the potential presence of accretion disks. Absorption by cool (~ 40-60 K) and hot gas (~ 250 K) is detected towards both binary components. The hot gas temperatures are lower than that in AFGL 2591 and 2136, making the presence of disks less likely. The line profiles of the two binary components are also very different, indicating different physical conditions. The detected CO absorption and emission seem consistent with a toroidal structure detected by ALMA.