Ionization of the Diffuse Interstellar Medium by O Stars and the Time Integrated Spectrum of a Supernova Remnant

Details Ionization of the Diffuse Interstellar Medium by O Stars and the Time Integrated Spectrum of a Supernova Remnant Ionization of the Diffuse Interstellar Medium by O Stars and the Time Integrated Spectrum of a Supernova Remnant

Jan 1994

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994phdt........26m&link_type=abstract

PhD Dissertation, Wisconsin Univ. Madison, WI United States

Astronomy and Astrophysics

Astronomy

2

H Ii Regions, Interstellar Matter, Ionized Gases, O Stars, Supernova Remnants, Astronomical Models, Cosmic X Rays, Electron Density (Concentration), Mathematical Models, Pulsars, Gas Ionization, H Alpha Line

Scientific paper

The diffuse interstellar medium (DISM) fills the majority of the Galactic volume, contains roughly one-third of all interstellar matter, and acts as the ambient environment in which dense clouds, cosmic rays, and most stars evolve. Its pervasiveness ensures it an active role in many important Galactic mechanisms, establishing an urgency to understand thoroughly its nature and the interactions between this medium and the host of denser 'contaminants' that exist within it. The work presented in this dissertation demonstrates our efforts at better understanding processes that affect aspects of the DISM. First, we have explored the possibility that the diffuse ionized gas of the Galaxy is kept ionized by O stars, and that such gas consists of the dilute portions of O star HII regions in a multiple component interstellar medium. To make this exploration, we calculated the HII region structures for the known galactic O stars and compared the integral properties of the ensemble (dispersion and emission measures) with the observational data. With the simplified assumptions of our standard cloud model, good quantitative agreement is found for the electron density as a function of z and the dispersion measures to pulsars at high and low latitudes as well as quantitative agreement for summary measures such as the mean vertical column density of electrons, the average H-alpha surface brightness perpendicular to the galactic plane, and its decrease at high latitude. Second, we present preliminary results of a project that estimates the x-ray surface brightness of a galaxy due to a steady state population of supernova remnants. Previous estimates of the surface brightness contribution from supernova remnants, limited by x-ray observations, marginally threaten or eliminate popular ideas concerning the diffuse interstellar medium density in galaxies. We improve upon this analysis by accurately modeling remnant evolution numerically, making possible a detailed description of the total x-ray emission of a remnant over its lifetime. The specifics of the numerical modeling and the results for a standard case are explored in detail.

Affiliated with

Also associated with

No associations

Rating

Ionization of the Diffuse Interstellar Medium by O Stars and the Time Integrated Spectrum of a Supernova Remnant does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Ionization of the Diffuse Interstellar Medium by O Stars and the Time Integrated Spectrum of a Supernova Remnant, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ionization of the Diffuse Interstellar Medium by O Stars and the Time Integrated Spectrum of a Supernova Remnant will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1685292