Properties of giant molecular clouds in the strongly barred galaxy
  NGC1300
  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 GMCs properties,
because the SFE is clearly lower in bar regions than in arm regions. In this
paper, we present the $^{12}$CO($1-0$) observations toward the western bar, arm
and bar-end regions of the strongly barred galaxy NGC1300 with ALMA 12-m array
at a high angular resolution of $\sim$40 pc. We detected GMCs associated with
the dark lanes not only in the arm and bar-end 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 NGC1300.
