Luminosity Indicators in Dusty Photoionized Environments (CROSBI ID 134433)
Prilog u časopisu | izvorni znanstveni rad | međunarodna recenzija
Podaci o odgovornosti
Bottorff, Michael ; Lamothe, Joseph ; Momjian, Emmanuel ; Verner, Egerland ; Vinković, Dejan ; Ferland, Gregg
engleski
Luminosity Indicators in Dusty Photoionized Environments
The luminosity of the central source in ionizing radiation is an essential parameter in a photoionized environment and is one of the most fundamental physical quantities one can measure. We outline a method of determining the luminosity for any emission-line region using only infrared data. In dusty environments, grains compete with hydrogen in absorbing continuum radiation. Grains produce infrared emission, and hydrogen produces recombination lines. We have computed a very large variety of photoionization models, using ranges of abundances, grain mixtures, ionizing continua, densities, and ionization parameters. The conditions were appropriate for such diverse objects as H ii regions, planetary nebulae, starburst galaxies, and the narrowand broad-line regions of active nuclei. The ratio of the total thermal grain emission relative to Hb (IR/Hb) is the primary indicator of whether the cloud behaves as a classical Stro¨mgren sphere (a hydrogen-bounded nebula) or whether grains absorb most of the incident continuum (a dust-bounded nebula). We find two global limits: when , infrared recombination lines determine the source luminosity in ionizing photons ; when IR/Hb ! 100 , the grains act as a bolometer to measure the luminosity.
H II regions; infrared: general; infrared: stars; methods: observational; planetary nebulae; stars: fundamental parameters
nije evidentirano
nije evidentirano
nije evidentirano
nije evidentirano
nije evidentirano
nije evidentirano
Podaci o izdanju
110 (751)
1998.
1040-1045-x
objavljeno
0004-6280
Povezanost rada
Fizika, Informacijske i komunikacijske znanosti