English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

We present the results of the Nobeyama Radio Observatory (NRO) M33 All Disk(30'x30' or 7.3 kpc x 7.3 kpc) Survey of Giant Molecular Clouds (NRO MAGiC)based on 12CO (1-0) observations using the NRO 45-m telescope. The spatialresolution of the resultant map is 19".3, corresponding to 81 pc, which issufficient to identify each Giant Molecular Cloud (GMC) in the disk. We foundclumpy structures with a typical spatial scale of ~100 pc, corresponding toGMCs, and no diffuse, smoothly distributed component of molecular gas at thissensitivity. Closer inspection of the CO and HI maps suggests that not every COemission is associated with local HI peaks, particularly in the inner portionof the disk (r < 2 kpc), although most of CO emission is located at the localHI peaks in the outer radii. We found that most uncovered GMCs are accompaniedby massive star-forming regions, although the star formation rates (SFRs) varywidely from cloud to cloud. The azimuthally averaged H{\sc i} gas surfacedensity exhibits a flat radial distribution. However, the CO radialdistribution shows a significant enhancement within the central 1-2 kpc region,which is very similar to that of the SFR. We obtained a map of the molecularfraction, f_mol = Sigma_H_2/(Sigma_HI+Sigma_H_2, at a 100-pc resolution. Thisis the first f_mol map covering an entire galaxy with a GMC-scale resolution.We find that f_mol tends to be high near the center. The correlation betweenf_mol and gas surface density shows two distinct sequences. The presence of twocorrelation sequences can be explained by differences in metallicity, i.e.,higher (~ 2-fold) metallicity in the central region (r< 1.5 kpc) than in theouter parts. Alternatively, differences in scale height can also account forthe two sequences, i.e., increased scale height toward the outer disk.

NRO M33 All Disk Survey of Giant Molecular Clouds (NRO MAGiC): I. HI to H_2 Transition