The case for diffuse, collisionally ionised interstellar CIV and SiIV below Z=1 kpc
Abstract
The results of a study of highly ionized gas in the galactic disc and disc/halo interface region are presented, based on IUE observations of C IV and Si IV absorption in a specially selected set of 19 co-directional sight-lines to early-type stars. Evidence is presented for a generally distributed, collisionally ionized phase of this gas having a density in the plane of ≡3×10-9cm-3 and a scale height in the range of 1 - 3 kpc. It is shown that the use in a restricted range of sight-line directions in studies such as this may reduce confusion resulting from inhomogeneities in the distribution of the highly ionized medium.
- Publication:
-
New Insights in Astrophysics. Eight Years of UV Astronomy with IUE
- Pub Date:
- September 1986
- Bibcode:
- 1986ESASP.263..577H
- Keywords:
-
- Astrophysics;
- Carbon;
- Gas Density;
- Gas Ionization;
- Interstellar Chemistry;
- Interstellar Gas;
- Silicon;
- Iue;
- Line Spectra;
- Ultraviolet Spectra