|Author||Icke, V. ♦ Gatley, I. ♦ israel, F. P.|
|Source||United States Department of Energy Office of Scientific and Technical Information|
|Subject Keyword||CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS ♦ REGIONS ♦ INFRARED RADIATION ♦ RADIOWAVE RADIATION ♦ COSMIC DUST ♦ ELECTROMAGNETIC RADIATION ♦ EMISSIVITY ♦ INTERSTELLAR GRAINS ♦ IONIZATION ♦ LYMAN LINES ♦ PHOTONS ♦ STARS ♦ COSMIC RADIO SOURCES ♦ DUSTS ♦ ELEMENTARY PARTICLES ♦ MASSLESS PARTICLES ♦ OPTICAL PROPERTIES ♦ PARTICLES ♦ PHYSICAL PROPERTIES ♦ RADIATIONS ♦ SURFACE PROPERTIES ♦ Astrophysics & Cosmology- Galaxies|
|Abstract||We present detailed calculations for the observational appearance of nonspherical Stroemgren regions at radio and infrared wavelengths. The computations are made feasible by two assumptions, namely (1) no stellar photon leaves the solid angle within which it was emitted, and (2) the radiation spectrum can be represented by three delta functions corresponding to Lyman continuum, Lyman alpha, and softer radiation, respectively. On the basis of these calculations we show models for the H II blisters M17 A and 30 Doradus, and also first order parameters for a sample of other well-studied galactic H II regions. From all this, we conclude that the observations are well explained by an ionizing object in a density gradient, without the need for peculiar dust properties or distribution. In particular, we are able to reproduce the displacement of the emission maxima in the direction in which the density of the ambient medium increases. Hereby we find further support for the blister picture and, indirectly, for models of star formation that describe the birth of massive stars near the outer parts of dense clouds.|
|Learning Resource Type||Article|
|Publisher Department||California Institute of Technologt and University of Minnesota, Minneapolis|
|Publisher Place||United States|
|Organization||California Institute of Technologt and University of Minnesota, Minneapolis|
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