open access

https://hdl.handle.net/2115/78945

Properties of giant molecular clouds in the strongly barred galaxy NGC 1300

英語

galaxies: star formation

2020-04

Oxford University Press

Monthly notices of the royal astronomical society

493(4)

5045-5061

Star formation activity depends on galactic-scale environments. To understand the variations in star formation activity, 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 GMC properties, because the SFE is clearly lower in bar regions than in arm regions. In this paper, we present the (CO)-C-12(1 - 0) observations towards the western bar, arm, and bar-end regions of the strongly barred galaxy NGC 1300 with ALMA 12-m array at a high angular resolution of similar to 40 pc. We detected GMCs associated with the dark lanes not only in the arm and barend regions but also in the bar region, where massive star formation is not seen. Using the CPROPS algorithm, we identified and characterized 233 GMCs across the observed regions. Based on the Kolmogorov-Smirnov test, we find that there is virtually no significant variations in GMC properties (e.g. radius, velocity dispersion, molecular gas mass, and virial parameter) among the bar, arm, and bar-end region. These results suggest that 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 the GMCs such as fast cloud-cloud collisions in NGC 1300.

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This article has been accepted for publication in Monthly notices of the royal astronomical society ©:2020 Published by Oxford University Press on behalf of The Royal Astronomical Society. All rights reserved.

0035-8711