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http://inaoe.repositorioinstitucional.mx/jspui/handle/1009/1016| Comparison of ¹³co line and far-infrared continuum emission as a diagnostic of dust and molecular gas physical conditions: I. Motivation and modeling | |
| WILLIAM FRANK WALL | |
| Acceso Abierto | |
| Atribución-NoComercial-SinDerivadas | |
| Determining temperatures in molecular clouds from ratios of CO rotational lines or from ratios of continuum emission in different wavelength bands suffers from reduced temperature sensitivity in the high-temperature limit. In theory, the ratio of far-IR, submillimeter, or millimeter continuum to that of a ¹³CO (or C¹⁸O) rotational line can place reliable upper limits on the temperature of the dust and molecular gas. Consequently, far-infrared continuum data from the COBE/DIRBE instrument and Nagoya 4-m ¹³CO J = 1 → 0 spectral line data were used to plot 240 μm/¹³CO J = 1 → 0 intensity ratios against 140 μm/240 μm dust color temperatures, allowing us to constrain the multiparsec-scale physical conditions in the OrionA and B molecular clouds. The best-fitting models to the Orion clouds consist of two components: a component near the surface of the clouds that is heated primarily by a very large-scale (i.e. ∼ 1 kpc) interstellar radiation field and a component deeper within the clouds. The former has a fixed temperature and the latter has a range of temperatures that varies from one sightline to another. The models require a dust-gas temperature difference of 0±2K and suggest that 40-50% of the Orion clouds are in the form of dust and gas with temperatures between 3 and 10K. These results have a number implications that are discussed in detail in later papers. These include stronger dust-gas thermal coupling and higher Galactic-scale molecular gas temperatures than are usually accepted, an improved explanation for the N(H₂)/I(CO) conversion factor, and ruling out one dust grain alignment mechanism. | |
| Monthly notices of the royal astronomical society | |
| 2007 | |
| Artículo | |
| Inglés | |
| Estudiantes Investigadores Público en general | |
| Wall, W. F., (2007). Comparison of ¹³co line and far-infrared continuum emission as a diagnostic of dust and molecular gas physical conditions: I. Motivation and modeling, Monthly notices of the royal astronomical society, Vol.375(1): 278-300 | |
| ASTRONOMÍA Y ASTROFÍSICA | |
| Versión aceptada | |
| acceptedVersion - Versión aceptada | |
| Aparece en las colecciones: | Artículos de Astrofísica |
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| 48_Comparison of 13CO and Far-IR -3.pdf | 1.93 MB | Adobe PDF | Visualizar/Abrir |