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EPoS |
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EPoS Contribution
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Insights from ASHES: Core Characteristics in 70 µm Dark High-mass Clumps
Kaho Morii UTokyo, NAOJ, Tokyo, JP | |
| Our ALMA Survey of 70 µm Dark High-mass Clumps in Early Stages (ASHES) provides unprecedented insights into the very early stages of high-mass star formation. Thanks to the high angular resolution (1.2" or ~4800 au), high sensitivity (~0.25 K), and large mosaic areas (~1 pc), we identify 839 cores within thirty-nine clumps, dense parts of infrared dark clouds. This large sample enables a statistical analysis of the embedded cores. The observed core masses and separations are consistent with thermal Jeans fragmentation, and 90% of the clumps host only low to intermediate mass cores. Even with this large sample, we find no high-mass prestellar cores (>30 Msun). Additionally, we observe a correlation between the protostellar core fraction and the mass dynamic range within the clumps, implying an increase in more massive objects as the clumps evolve. The picture found in the ASHES project favors the clump-fed accretion scenario where low-mass, gravitationally unstable cores initially form through the thermal Jeans fragmentation, and cores that succeed in gas feeding can become massive. | |
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| Caption: Dust continuum map of thirty-nine IRDCs obtained by ALMA. The internal structures of the IRDCs and embedded cores have been revealed. The scale bar in each panel represents 0.1 pc. Credit: ALMA(ESO/NAOJ/NRAO), K. Morii et al. | |
| Collaborators: P. Sanhueza, NAOJ, JP F. Nakamura, NAOJ, JP and the ASHES team |
Key publication
Relevant topic(s): Cores Fragmentation High-Mass SF |
| Relevant Big Question: What is the initial condition of high-mass star formation? | |