Speaker
Description
Anekwe, Frances Ngozika1, Prof. James O. Chibueze2, Prof. A.E. Chukwude3, and Dr. Saul Paul Phiri4.
Department of Physics, School of Mathematics and Natural Sciences, Copperbelt University,Riverside,Zambia1,4,
UNISA Centre for Astrophysics & Space Sciences (U-CASS), Florida Campus, South Africa2,
Department of Physics and Astronomy, UNN, Enugu, Nigeria1, 3.
fn.anekwe@coou.edu.ng1,chibujo@unisa.ac.za2,augustine.chukwude@unn.edu.ng3,saulphiri@gmail.com4.
Class II methanol masers at 6.7 GHz and 12.2 GHz are powerful tracers of the environments surrounding massive young stellar objects (MYSOs). Massive stars are rare and they are generally found at great distances away from the sun, it is then difficult to study them and their impact on their environment during their earliest stages of formation. Hence the advent of masers (Microwave Amplification Stimulation by Radiation Emission) have provided important tools for studying high mass star forming regions (HMSFRs). In as-much-as the single-dish monitoring has identified numerous periodic sources, its deficiences in calibration stability and angular resolution have prevented a definitive link between the maser variability and the underlying protostellar dynamics. This work aims to help resolve the debate between binary, accretion, and pulsation models by establishing a direct link between maser flux changes and the physical structures of massive young stellar objects. We utilize archival ALMA observations focusing on a sample of five known periodic maser sources. We apply robust calibration and self-calibration techniques in CASA to this multi-source ALMA dataset to produce high-fidelity light curves and spectral maps. Our methodology involves the robust calibration of multi-epoch ALMA data, spectral and light-curve analysis to characterize periodicity, and the precise mapping of maser spots relative to continuum emission from disks and outflows.The findings critically evaluate theoretical models of maser pumping and provide new insights into the dynamic processes governing the earliest stages of massive stellar evolution.
Keywords: Masers- high star forming regions- ISM: clouds – H II regions – radio lines.
| Stream | Science or Engineering |
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