Orateur
Description
The central molecular zone (CMZ) of our Galaxy hosts an extreme interstellar environment analogous to that found in typical starburst galaxies in the distant Universe. In order to understand dust properties in such environments, we have conducted a survey of the CMZ with the AzTEC/Large Millimeter Telescope (LMT) in the 1.1 mm continuum. This survey has been analyzed together with complementary low resolution millimeter and far-IR data data, using a novel Bayesian modeling that enables the full utilization of our high-resolution (10.5 arcsec) map at 1.1 mm and reveals unprecedentedly detailed information on the spatial distributions of dust column density, temperature, and spectral index across the CMZ. In particular, we find a remarkable trend of increasing index, from 2.0 to 2.4, towards dense peaks in the CMZ, indicating a deficiency of large grains or a fundamental change in dust optical properties. This environmental dependence of the index has a significant impact on the determination of dust temperature. A proposed 50-m LMT/TolTEC survey in the 2023 spring will hopefully lead to a simultaneous mapping of the CMZ in the 1.1, 1.4, and 2 mm bands, enabling a decomposition of dust, free-free, and synchrotron emissions and advancing our understanding of dust properties, star formation, and energetic feedback in the extreme interstellar environment.
