Structure and spectrum of quiescent prominences. IV. the ultraviolet ionization continua of hydrogen and helium

Journal Article · Sun May 01 00:00:00 EDT 1983 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/160965· OSTI ID:5838738

Heasley, J N; Milkey, R W

The formation of the ground-state ionization continua of hydrogen and neutral helium in quiscent prominences has been investigated by using isothermal and isobaric slab models. The hydrogen and helium ionization equilibria are dominated by the extreme ultraviolet radiation field incident on the prominence. The Lyman continuum brightness is dependent only on the incident radiation and the optical thickness of the prominence. The ratio of the intensity in the He I to the Lyman continuum is principally a function of the hardness of the incident radiation and the helium abundance and is only secondarily a function of the optical thickness of the slab and the gas pressure. The color temperatures of the continua, when corrected for optical depth effects, are good indicators of the electron temperature in the prominence. The slab models used in this study, which were developed to reproduce the visible spectrum hydrogen and helium lines, are in rasonable agreement with existing ultraviolet observations.

• Research Organization: Institute for Astronomy, University of Hawaii
• OSTI ID: 5838738
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 268:1; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ELECTROMAGNETIC RADIATION
ELEMENTS
ENERGY LEVELS
EXTREME ULTRAVIOLET RADIATION
FLUIDS
GASES
GROUND STATES
HELIUM
HYDROGEN
IONIZATION
NONMETALS
RADIATIONS
RARE GASES
SOLAR ACTIVITY
SOLAR PROMINENCES
SPECTRA
ULTRAVIOLET RADIATION
ULTRAVIOLET SPECTRA
VISIBLE SPECTRA