Fang-Chun Liu (Earth Sciences, National Taiwan Normal University); Yi-Jehng Kuan(Earth Sciences, NTNU); Ya-Wen Yo(Earth Sciences, NTNU); Yo-Ling Chuang(Earth Sciences, NTNU)
The Orion Kleinmann–Low (Orion KL) hot molecular core, one of the richest molecular reservoirs in the Milky Way, is the nearest massive star-forming region to Earth. In this study, we investigate the physical and chemical structure of the (sub)millimeter continuum sources in Orion KL using the Atacama Large Millimeter/submillimeter Array (ALMA) in ALMA Bands 4, 6, and 7. As a result, twenty-four distinct continuum sources are clearly identified. In addition, we characterize the physical attributes of each individual continuum source by measuring their spectral indices, LSR velocities, and kinetic temperatures. We found spectral indices, velocities and temperatures of these continuum sources fall within the ranges of, respectively, from ~0.5 to 3.5, ~2 to 10 km/s, and ~50 to 250 K. Moreover, discernible spatial distributions and chemical abundances of nitrogen- and oxygen-bearing molecules are also inferred based on the continuum and spectral emission we observed. Correlations between the physical and chemical parameters, e.g. temperatures and nitrogen-bearing molecular species, are evident which may be attributed to different evolutionary stages of individual continuum sources.