Resumo

WALL, W. F.. The N(H₂)/I(CO) Conversion Factor: A Treatment that Includes Radiative Transfer. Rev. mex. astron. astrofis [online]. 2006, vol.42, n.1, pp.117-126. ISSN 0185-1101.

A treatment that better explains the N(Fi2)/I(CO) conversion factor is given that includes radiative transfer. At first glance, involving radiative transfer seems superfluous for an optically thick line such as CO J = 1 → 0 line. However, given that the interstellar medium is inhomogeneous, the individual gas fragments (i.e., clumps) can still be optically thin toward their edges and in the wings of their line profiles. The statistical treatment by Martin et al. (1984) of the radiative transfer through a clumpy molecular cloud is used to derive an expression for the conversion factor that overcomes the shortcomings in the more traditional explanations based on Dickman et al. (1986). While possibly representing important step forward in understanding the N(H2)/I(CO) conversion factor, the treatment here also has shortcomings of its own that are briefly discusse.

Palavras-chave : ISM [MOLECULES]; ISM [DUST]; ISM [ORION].

        · resumo em Espanhol     · texto em Inglês     · Inglês ( pdf )