| dc.creator | WILLIAM FRANK WALL | |
| dc.date | 2007 | |
| dc.date.accessioned | 2023-07-25T16:22:50Z | |
| dc.date.available | 2023-07-25T16:22:50Z | |
| dc.identifier | http://inaoe.repositorioinstitucional.mx/jspui/handle/1009/1016 | |
| dc.identifier.uri | https://repositorioslatinoamericanos.uchile.cl/handle/2250/7806216 | |
| dc.description | 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. | |
| dc.format | application/pdf | |
| dc.language | eng | |
| dc.publisher | Monthly notices of the royal astronomical society | |
| dc.relation | citation: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 | |
| dc.rights | info:eu-repo/semantics/openAccess | |
| dc.rights | http://creativecommons.org/licenses/by-nc-nd/4.0 | |
| dc.subject | info:eu-repo/classification/cti/1 | |
| dc.subject | info:eu-repo/classification/cti/21 | |
| dc.subject | info:eu-repo/classification/cti/21 | |
| dc.title | Comparison of ¹³co line and far-infrared continuum emission as a diagnostic of dust and molecular gas physical conditions: I. Motivation and modeling | |
| dc.type | info:eu-repo/semantics/article | |
| dc.type | info:eu-repo/semantics/acceptedVersion | |
| dc.audience | students | |
| dc.audience | researchers | |
| dc.audience | generalPublic | |
