منابع مشابه
HE I 2.06 Micron Emission from Nebulae
The spectrum emitted by any astronomical plasma is sensitive to a variety of details, some of which may not be obviously important. This paper describes the sensitivity of the He I 2.06 km line to the gas opacity at ionizing energies. The intensity of the line relative to a hydrogen line depends on the He`/H` ratio, but also on the ratio of continuous to He I Lya line opacity, since this determ...
متن کاملEvolution of Gaseous Nebulae.
55Swain, F. M., A Blumentals, and N. Prokopovich, "Bituminous and other organic substances in Pre-Cambrian of Minnesota," Am. Assoc. Petrol. Geol. Bull., 42, 173-189 (1958). M Timofeev, B. V., "Spores and phytoplankton from Proterozoic and early Paleozoic of Eurasia," in Proc. 21st Int. Geol. Congr., Copenhagen, Rept. Soviet Geologists, Problem 9, 177-188 (1960) (in Russian; English abstract, p...
متن کاملTime dependent ionization calculations of gaseous nebulae
We developed a new computer code which is able to treat the time dependent photoand collisional ionization of gaseous nebulae together with the consistent energy balance for arbitrary numbers of elements, ions and line transitions. The intention of this paper is to describe the basic numerical methods and a few test calculations as being parts of full spherically symmetric radiation-gasdynamic ...
متن کاملIonization Structure and Spectra of Iron in Gaseous Nebulae
The emission spectra and the ionization structure of the low ionization stages of iron, Fe I–IV, in gaseous nebulae are studied. This work includes: (i) new atomic data: photoionization cross sections, total e-ion recombination rates, excitation collision strengths, and transition probabilities calculated under the Iron Project by the Ohio State atomic-astrophysics group; (ii) detailed study of...
متن کاملAn empirical calibration of sulphur abundance in ionised gaseous nebulae
We have derived an empirical calibration of the abundance of S/H as a function of the S23 parameter, defined using the bright sulphur lines of [SII] and [SIII]. Contrary to what is the case for the widely used O23 parameter, the calibration remains single valued up to the abundance values observed in the disk HII regions. The calibration is based on a large sample of nebulae for which direct de...
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ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 1980
ISSN: 0035-8711,1365-2966
DOI: 10.1093/mnras/191.2.243