ALMA Survey of Orion Planck Galactic Cold Clumps (ALMASOP): Discovery of an Extremely Dense and Compact Object Embedded in the Prestellar Core G208.68-19.92-N2

Naomi Hirano*, Dipen Sahu, Sheng Yaun Liu, Tie Liu, Ken’ichi Tatematsu, Somnath Dutta, Shanghuo Li, Chin Fei Lee, Pak Shing Li, Shih Ying Hsu, Sheng Jun Lin, Doug Johnstone, Leonardo Bronfman, Huei Ru Vivien Chen, David J. Eden, Yi Jehng Kuan, Woojin Kwon, Chang Won Lee, Hong Li Liu, Mark G. RawlingsIsabelle Ristorcelli, Alessio Traficante

*此作品的通信作者

研究成果: 雜誌貢獻期刊論文同行評審

2 引文 斯高帕斯(Scopus)

摘要

The internal structure of the prestellar core G208.68-19.02-N2 (G208-N2) in the Orion Molecular Cloud 3 (OMC-3) region has been studied with the Atacama Large Millimeter/submillimeter Array. The dust continuum emission revealed a filamentary structure with a length of ∼5000 au and an average H2 volume density of ∼6 × 107 cm−3. At the tip of this filamentary structure, there is a compact object, which we call a nucleus, with a radius of ∼150-200 au and a mass of ∼0.1 M . The nucleus has a central density of ∼2 × 109 cm−3 with a radial density profile of r −1.87±0.11. The density scaling of the nucleus is ∼3.7 times higher than that of the singular isothermal sphere (SIS). This as well as the very low virial parameter of 0.39 suggests that the gravity is dominant over the pressure everywhere in the nucleus. However, there is no sign of CO outflow localized to this nucleus. The filamentary structure is traced by the N2D+ 3-2 emission, but not by the C18O 2-1 emission, implying the significant CO depletion due to high density and cold temperature. Toward the nucleus, the N2D+ also shows the signature of depletion. This could imply either the depletion of the parent molecule, N2, or the presence of the embedded very-low luminosity central source that could sublimate the CO in the very small area. The nucleus in G208-N2 is considered to be a prestellar core on the verge of first hydrostatic core (FHSC) formation or a candidate for the FHSC.

原文英語
文章編號123
期刊Astrophysical Journal
961
發行號1
DOIs
出版狀態已發佈 - 2024 1月 1

ASJC Scopus subject areas

  • 天文和天體物理學
  • 空間與行星科學

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