Investigating the Earliest Stages of High-Mass Star Formation

High-mass stars play a critical role in shaping the evolution of galaxies as they enrich the interstellar medium through stellar winds and supernovae. Understanding the formation of these stars is vital for refining models of galaxy formation and evolution. To shed light on the early stages of high-mass star formation, we can utilize interstellar masers, particularly the class II methanol masers at 6.7 GHz, which are exclusively observed in massive star-forming regions. Our study focuses on exploring the various aspects of massive star formation using 6.7 GHz methanol masers as indicators. Firstly, we investigate whether the maser luminosity correlates with the physical properties of the hosting clumps. This would provide insight into whether maser luminosity can serve as a tool to identify specific evolutionary phases in high-mass star formation. Secondly, we employ maser emissions to study star formation on larger scales. Since 6.7 GHz masers are associated with early stages of high-mass star formation, searching for regions abundant in these maser detections, allows us to investigate relatively young star-forming sites. We analyze such a star forming region- Bubble N59- which harbors almost 8 6.7 GHz methanol masers, numerous compact HII regions, massive clumps, filaments, and bright rims. To characterize the N59 region comprehensively, we utilize multiwavelength data obtained from various surveys. Our molecular study uncovers two distinct molecular clouds in the region, which, although spatially close, occupy different regions in velocity space. We also propose that the feedback from the HII regions has led to the formation of prominent Bright Rimmed Clouds (BRC) within our region of interest. Lastly, we investigate how massive stars gain mass by analyzing maser bursts. Since there has been strong evidence that maser flares are driven by accretion bursts, tracing for maser flaring events helps us track the episodic accretion in massive stars. We specifically analyze the most recent maser flaring event associated with the IR source AGAL36.11+0.55. Remarkably, this represents only the second flaring maser source observed within the NIR range. To gather observational data, we employ Indian facilities such as TIRSPEC and TANSPEC to study the associated massive young stellar object and determine whether the maser flares are indeed linked to accretion burst.