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Author Shimoikura, Tomomi ♦ Dobashi, Kazuhito ♦ Nakamura, Fumitaka ♦ Hara, Chihomi ♦ Kawabe, Ryohei ♦ Tanaka, Tomohiro ♦ Shimajiri, Yoshito ♦ Sugitani, Kouji
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword ASTROPHYSICS, COSMOLOGY AND ASTRONOMY ♦ ABSORPTION SPECTRA ♦ CARBON 12 ♦ CARBON 13 ♦ CARBON MONOXIDE ♦ CLOUDS ♦ EMISSION SPECTRA ♦ GHZ RANGE ♦ HYDROGEN IONS ♦ IMAGES ♦ INTERSTELLAR SPACE ♦ MOLECULES ♦ SENSITIVITY ♦ STARS ♦ TELESCOPES ♦ VELOCITY
Abstract We report the results of the {sup 12}CO (J = 3−2) and HCO{sup +} (J = 4−3) observations of the W40 H ii region with the Atacama Submillimeter Telescope Experiment (ASTE) 10 m telescope (HPBW ≃ 22″) to search for molecular outflows and dense clumps. We found that the velocity field in the region is highly complex, consisting of at least four distinct velocity components at V{sub LSR} ≃ 3, 5, 7, and 10 km s{sup −1}. The ∼7 km s{sup −1} component represents the systemic velocity of cold gas surrounding the entire region, and causes heavy absorption in the {sup 12}CO spectra over the velocity range 6 ≲ V{sub LSR} ≲ 9 km s{sup −1}. The ∼5 and ∼10 km s{sup −1} components exhibit high {sup 12}CO temperature (≳40 K) and are found mostly around the H ii region, suggesting that these components are likely to be tracing dense gas interacting with the expanding shell around the H ii region. Based on the {sup 12}CO data, we identified 13 regions of high velocity gas, which we interpret as candidate outflow lobes. Using the HCO{sup +} data, we also identified six clumps and estimated their physical parameters. On the basis of the ASTE data and near-infrared images from 2MASS, we present an updated three-dimensional model of this region. In order to investigate molecular outflows in W40, the SiO (J = 1−0, v = 0) emission line and some other emission lines at 40 GHz were also observed with the 45 m telescope at the Nobeyama Radio Observatory, but they were not detected at the present sensitivity.
ISSN 0004637X
Educational Use Research
Learning Resource Type Article
Publisher Date 2015-06-20
Publisher Place United States
Journal Astrophysical Journal
Volume Number 806
Issue Number 2


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