1. The ALMA-QUARKS Survey: II. the ACA 1.3 mm continuum source catalog and the assembly of dense gas in massive star-forming clumps
- Author
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Xu, Fengwei, Wang, Ke, Liu, Tie, Zhu, Lei, Garay, Guido, Liu, Xunchuan, Goldsmith, Paul, Zhang, Qizhou, Sanhueza, Patricio, Qin, Shengli, He, Jinhua, Juvela, Mika, Tej, Anandmayee, Liu, Hongli, Li, Shanghuo, Morii, Kaho, Zhang, Siju, Zhou, Jianwen, Stutz, Amelia, Evans, Neal J., Kee-Tae, Kim, Liu, Shengyuan, Mardones, Diego, Li, Guangxing, Bronfman, Leonardo, Tatematsu, Ken'ichi, Lee, Chang Won, Lu, Xing, Mai, Xiaofeng, Jiao, Sihan, Chibueze, James O., Su, Keyun, Toth, L. Viktor, Xu, Fengwei, Wang, Ke, Liu, Tie, Zhu, Lei, Garay, Guido, Liu, Xunchuan, Goldsmith, Paul, Zhang, Qizhou, Sanhueza, Patricio, Qin, Shengli, He, Jinhua, Juvela, Mika, Tej, Anandmayee, Liu, Hongli, Li, Shanghuo, Morii, Kaho, Zhang, Siju, Zhou, Jianwen, Stutz, Amelia, Evans, Neal J., Kee-Tae, Kim, Liu, Shengyuan, Mardones, Diego, Li, Guangxing, Bronfman, Leonardo, Tatematsu, Ken'ichi, Lee, Chang Won, Lu, Xing, Mai, Xiaofeng, Jiao, Sihan, Chibueze, James O., Su, Keyun, and Toth, L. Viktor
- Abstract
Leveraging the high resolution, high sensitivity, and wide frequency coverage of the Atacama Large Millimeter/submillimeter Array (ALMA), the QUARKS survey, standing for "Querying Underlying mechanisms of massive star formation with ALMA-Resolved gas Kinematics and Structures", is observing 139 massive star-forming clumps at ALMA Band 6 ($\lambda\sim$ 1.3 mm). This paper introduces the Atacama Compact Array (ACA) 7-m data. Combining multi-wavelength data, we provide the first edition of QUARKS atlas, offering insights into the multiscale and multiphase interstellar medium in high-mass star formation. The ACA 1.3 mm catalog includes 207 continuum sources that are called ACA sources. Their gas kinetic temperatures are estimated using three formaldehyde (H$_2$CO) transitions with a non-LTE radiation transfer model, and the mass and density are derived from a dust emission model. The ACA sources are massive (16-84 percentile values of 6-160 $M_{\odot}$), gravity-dominated ($M\propto R^{1.1}$) fragments within massive clumps, with supersonic turbulence ($\mathcal{M}>1$) and embedded star-forming protoclusters. We find a linear correlation between the masses of the fragments and the massive clumps, with a ratio of 6% between the two. When considering the fragments as representative of dense gas, the ratio indicates a dense gas fraction (DGF) of 6%, although with a wide scatter ranging from 1% to 10%. If we consider the QUARKS massive clumps to be what is observed at various scales, then the size-independent DGF indicates a self-similar fragmentation or collapsing mode in protocluster formation. With the ACA data over four orders of magnitude of luminosity-to-mass ratio ($L/M$), we find that the DGF increases significantly with $L/M$, which indicates clump evolutionary stage. We observed a limited fragmentation at the subclump scale, which can be explained by dynamic global collapse process., Comment: 24 pages, 7 figures. Accepted for publication in Research in Astronomy and Astrophysics. QUARKS atlas link: https://drive.google.com/file/d/1KTqXxCDduYepvLd9kIvZVSSytK48OmfL/view?usp=sharing
- Published
- 2024