Optical emission line studies and the warm, ionized component of the Local Interstellar Medium

Technical Report · Thu Nov 01 04:00:00 EST 1984

OSTI ID:5760556

Reynolds, R J

Observations of diffuse, galactic H alpha, N2 lambda 6583, and S2 6716 emission lines provide evidence for a warm (10,000K), primarily ionized component of the interstellar medium distribution throughout the galactic disk. This component of the interstellar gas has an electron density approximately equals 0.1-0.2/cu cm and occupies about 10 to 30% of the interstellar volume. Interstellar H alpha emission near the galactic poles, the dispersion measure of a nearby pulsar, and observations of interstellar gas flowing into the solar system indicate that this ionized component is an important constituent of the interstellar medium in the solar neighborhood. The intensity of the H alpha background at high galactic latitudes implies that this component is maintained by an average hydrogen ionization rate in the vicinity of the Sun of (2-4) x 100,000 s(-1) per square cm of galactic disk. The emission measure is 1.3 to 2.3 cm (-6) pc toward the galactic poles. The sources of this ionization were not identified but may include escaping Lyman continuum radiation from planetary nebulae, hot white dwarfs, and early type stars.

• Research Organization: Wisconsin Univ., Madison (USA)
• OSTI ID: 5760556
• Report Number(s): N-85-15555
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BACKGROUND RADIATION
BALMER LINES
COSMIC GASES
COSMIC RADIATION
ELECTRON DENSITY
EMISSION SPECTRA
FLUIDS
GASES
INTERSTELLAR SPACE
IONIZED GASES
IONIZING RADIATIONS
MAIN SEQUENCE STARS
RADIATIONS
SPACE
SPECTRA
STARS
SUN