Abstract Details

Name: Rose Maria Mathew
Affiliation: Mahatma Gandhi University Kottayam
Conference ID: ASI2021_96
Title : Physical Conditions of 6.7 GHz Methanol Maser Hosts
Authors and Co-Authors : Rose Maria Mathew (Mahatma Gandhi University, Kottayam) and Jagadheep D. Pandian (Indian Institute of Space Science and Technology, Trivandrum)
Abstract Type : Poster
Abstract Category : Stars, ISM and Galaxy
Abstract : The process of massive star formation is still poorly understood, in part due to the difficulty in identifying massive star-forming regions in early phases. One of the signposts of the early phases of massive star formation is the presence of the 5_1 – 6_0 A+ maser line of methanol at 6.7 GHz. We have carried out observations of thermal lines of methanol at 96 and 241 GHz using the MOPRA and APEX telescopes respectively towards a sample of 6.7 GHz methanol masers detected by the Arecibo Methanol Maser Galactic Plane Survey. Physical parameters of the 6.7 GHz methanol maser hosts were derived from the spectral line modelling of the sources assuming local thermodynamic equilibrium (LTE) and non-LTE conditions. The derived excitation temperatures suggest subthermal excitation of the lines. Kinetic temperature and hydrogen density derived from 241 GHz data are found to be in the range 12 – 86 K and 10^5 –10^6 cm^(-3) respectively. For a few sources, the kinetic temperature is higher than in infrared dark clouds (IRDC) suggesting that these regions are comparatively more evolved than the IRDCs.