The ALMA survey of 70 μm dark high-mass clumps in early stages (ASHES)
| Autor: | Kaho Morii, Patricio Sanhueza, Fumitaka Nakamura, James M. Jackson, Shanghuo Li, Henrik Beuther, Qizhou Zhang, Siyi Feng, Daniel Tafoya, Andrés E. Guzmán, Natsuko Izumi, Takeshi Sakai, Xing Lu, Ken’ichi Tatematsu, Satoshi Ohashi, Andrea Silva, Fernando A. Olguin, Yanett Contreras |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
010308 nuclear & particles physics
Astrophysics - astrophysics of galaxies FOS: Physical sciences Astronomy and Astrophysics 01 natural sciences 7. Clean energy Astrophysics - solar and stellar astrophysics 787 1569 1565 732 844 13. Climate action Space and Planetary Science Astrophysics of Galaxies (astro-ph.GA) 0103 physical sciences 010303 astronomy & astrophysics Solar and Stellar Astrophysics (astro-ph.SR) |
| Zdroj: | The Astrophysical Journal, 923(2) |
| Popis: | With a mass of $\sim$1000 $M_\odot$ and a surface density of $\sim$0.5 g cm$^{-2}$, G023.477+0.114 also known as IRDC 18310-4 is an infrared dark cloud (IRDC) that has the potential to form high-mass stars and has been recognized as a promising prestellar clump candidate. To characterize the early stages of high-mass star formation, we have observed G023.477+0.114 as part of the ALMA Survey of 70 $\mu$m Dark High-mass Clumps in Early Stages (ASHES). We have conducted $\sim$1."2 resolution observations with the Atacama Large Millimeter/submillimeter Array (ALMA) at 1.3 mm in dust continuum and molecular line emission. We identified 11 cores, whose masses range from 1.1 $M_\odot$ to 19.0 $M_\odot$. Ignoring magnetic fields, the virial parameters of the cores are below unity, implying that the cores are gravitationally bound. However, when magnetic fields are included, the prestellar cores are close to virial equilibrium, while the protostellar cores remain sub-virialized. Star formation activity has already started in this clump. Four collimated outflows are detected in CO and SiO. H$_2$CO and CH$_3$OH emission coincide with the high-velocity components seen in the CO and SiO emission. The outflows are randomly oriented for the natal filament and the magnetic field. The position-velocity diagrams suggest that episodic mass ejection has already begun even in this very early phase of protostellar formation. The masses of the identified cores are comparable to the expected maximum stellar mass that this IRDC could form (8-19 $M_\odot$). We explore two possibilities on how IRDC G023.477+0.114 could eventually form high-mass stars in the context of theoretical scenarios. Comment: Accepted for publication in ApJ (September 1, 2021). 33 pages, 20 figures, and 5 tables |
| Databáze: | OpenAIRE |
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