Oral Presentation
Properties of giant molecular clouds in the strongly barred galaxy NGC 1300
Presenter: Fumiya Maeda (Kyoto University)
Star formation activity depends on galactic-scale environments. To understand the variations, comparing the properties of giant molecular clouds (GMCs) among environments with different star formation efficiency (SFE) is necessary. We thus focus on a strongly barred galaxy to investigate the impact of the galactic environment on the GMCs properties, because the SFE is clearly lower in bar regions than in arm regions. In this paper, we present the 12CO(1 − 0) observations toward the western bar, arm and bar-end region of the strongly barred galaxy of NGC 1300 with ALMA 12 m array at a high angular resolution of ∼40 pc. We detected the GMC-like gas clouds associated with the dark lanes not only in the arm and bar-end region but also in the bar regions, where massive star formation is not seen. Using the CPROPS algorithm, we identified and characterized 233 GMCs across the observed regions. Comparing the physical properties of GMCs in the bar and arm region, we find no significant variation in GMC properties (e.g., radius, velocity dispersion, molecular gas mass, and virial parameter) except for peak temperature. These results suggest that the systematic differences in the physical properties of the GMCs are not the cause for SFE differences with environments, and that there should be other mechanisms which control the SFE of GMCs such as fast cloud-cloud collisions or/and a large amount of diffuse molecular gases in the bar of NGC 1300.
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