Astronomy and Astrophysics – Astrophysics
Scientific paper
1998-10-30
Astronomy and Astrophysics
Astrophysics
6 pages, Latex with 10 Postscript figures included. Uses blois.sty. To appear in Proc. of Xth Rencontres de Blois `The Birth o
Scientific paper
An extremely careful separation of the weak metal-line systems relating to the Lyman forest absorbers into individual ``single-phase ionization'' components with accurate parameters has yielded a large sample in the wide redshift range 1.9 < z < 4.4. The systems typically span several hundred km/s and within each the components show a strong coherence in their ionization properties. No sudden evolution is found in the column density ratio N(Si IV)/N(C IV), contrary to previous indication of a large change near z = 3, although there is an apparent rise below z~2.2 and above z~3.8. A smooth not sudden spectral evolution is reflected in the z distribution of N(N V)/N(C IV). Comparisons of N(Si IV)/N(C IV) vs N(C II)/N(C IV) from the observations with CLOUDY derived values using several model ionizing spectra show the general dominance of a QSO ionizing background at the lower redshifts while an additional strong and eventually dominating stellar contribution is required progressively to higher redshifts.
Boksenberg Alec
Rauch Michael
Sargent Wallace L. W.
No associations
LandOfFree
Metallic Absorbers and the Evolution of Galaxy Haloes and the Metagalactic Ionizing Background 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 Metallic Absorbers and the Evolution of Galaxy Haloes and the Metagalactic Ionizing Background, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Metallic Absorbers and the Evolution of Galaxy Haloes and the Metagalactic Ionizing Background will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-82493