2018/04/02 by Kunihiko Tanaka, Makoto Nagai, Kazuhisa Kamegai +3 · 1 citation
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Calibration #Center (category theory) #Galactic Center #Hydrogen molecule #Observatory #Position (finance) #Principal component analysis #Stellar, planetary, and galactic studies #Telescope #astro-ph.GA
paper · pdf · doi:10.3847/1538-4365/aab9a5
51 pages, 58 figures, Accepted for publication in Astrophysical Journal Supplement Series
arxiv created 2018/04/02 · openalex created_date 2018/04/13 · openalex publication_date 2018/06/01 · arxiv updated 2018/06/13 · openalex updated_date 2026/08/05
Abstract This supplement paper presents the maps of HCN J = 4–3, HNC J = 1–0, J = 1–0, and HC 3 N J = 10–9 for the Galactic central molecular zone (CMZ), which have been obtained using the Atacama Submillimeter Telescope Experiment and Nobeyama Radio Observatory 45 m telescope. Three-dimensional maps (2D in space and 1D in velocity) of the gas kinetic temperature ( T kin ), hydrogen volume density ( ), and fractional abundances of eight molecules (HCN, HNC, , HCO + , , SiO, CS, and ) have been constructed from our and archival data. We have developed a method with hierarchical Bayesian inference for this analysis, which has successfully suppressed the artificial correlations among the parameters created by systematic errors due to the deficiency in the simple one-zone excitation analysis and the calibration uncertainty. The typical values of T kin and are and , respectively, and the presence of an additional cold, low-density component is also indicated. The distribution of high-temperature regions is poorly correlated with known active star-forming regions, while a few of them coincide with shocked clouds. Principal component analysis has identified two distinct groups in the eight analyzed molecules: one group with large PC1 and PC2 scores, and the other with a large T kin dependence, which could be explained using two regimes of shock chemistry with fast ( ) and slow ( ) velocity shocks, respectively. This supports the idea that the mechanical sputtering of dust grains and the mechanical heating play primary roles in the chemical and thermal processes in CMZ clouds.