Sign on

SAO/NASA ADS Astronomy Abstract Service

· Find Similar Abstracts (with default settings below)
· Full Refereed Journal Article (PDF/Postscript)
· Full Refereed Scanned Article (GIF)
· References in the article
· Citations to the Article (180) (Citation History)
· Refereed Citations to the Article
· SIMBAD Objects (31)
· NED Objects (95)
· Also-Read Articles (Reads History)
·
· Translate This Page
Title:
C IV absorption systems in QSO spectra - Is the character of systems with Z(abs) = about Z(em) different from those with Z(abs) much less than Z(em)?
Authors:
Foltz, Craig B.; Weymann, Ray J.; Peterson, Bradley M.; Sun, Light; Malkan, Matthew A.; Chaffee, Frederic H., Jr.
Affiliation:
AA(Multiple Mirror Telescope Observatory, Tucson, AZ), AB(Steward Observatory, Tucson, AZ), AC(Ohio State University, Columbus), AD(Washington, University, Seattle), AE(California, University, Los Angeles)
Publication:
Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 307, Aug. 15, 1986, p. 504-534. Research supported by the University of Illinois. (ApJ Homepage)
Publication Date:
08/1986
Category:
Astrophysics
Origin:
STI
NASA/STI Keywords:
Absorption Spectra, Astronomical Spectroscopy, Quasars, Astronomical Catalogs, Carbon, Emission Spectra, Line Spectra, Red Shift
DOI:
10.1086/164440
Bibliographic Code:
1986ApJ...307..504F

Abstract

We present observations obtained at 1 Å spectral resolution and controlled S/N of a sample of 31 moderate-redshift QSOs in the spectral region containing the C IV λλl548, 1550 emission line. These spectra are analyzed to study the character of C IV absorption systems near the emission-line redshift and at Zabs < zem. The results are compared to those by Weymann, Williams, Peterson, and Turnshek, who observed essentially the same sample photographically, and the results of Young, Sargent, and Boksenberg, who observed an independent sample of comparable size. The observations reported here very strongly suggest that there is a difference in character between absorption complexes near the emission-line red shift and typical intervening absorption systems. We suggest that it is this difference which produces the peak in the C IV absorption-line distribution near the emission-line redshift which was found for this sample by Weymann et al. and which persists in this reobserved sample. At large displacements away from the emission line (v> 5000 km s-1), we find a distribution (presumably arising from intervening absorbing clouds) which is statistically identical to that found by Young, Sargent, and Boksenberg. We further find that it is extremely unlikely that the properties of the systems near the emission-line redshift are a result of sampling from the distributions of the properties of the intervening clouds. We suggest that most of the systems that we see in the vicinity of the emission line are drawn from a population distinct from that giving rise to most of the systems at large displacements. We reiterate the speculation that the population of absorbers responsible for the "associated" systems may represent absorption by clouds in a cluster containing the QSO, but we cannot exclude the possibility that these absorption complexes arise from material which has undergone mild acceleration by the QSO itself. We comment on a possibility that the difference between our results and those of Young, Sargent, and Boksenberg may arise from a difference in the radio properties between the two samples. This may be indicative of a difference in the typical environments of the QSOs in each sample which, in turn, may be responsible for the differences in the properties of the C IV absorption.

Printing Options

Print whole paper
Print Page(s) through

Return 600 dpi PDF to Acrobat/Browser. Different resolutions (200 or 600 dpi), formats (Postscript, PDF, etc), page sizes (US Letter, European A4, etc), and compression (gzip,compress,none) can be set through the Printing Preferences


More Article Retrieval Options

HELP for Article Retrieval
Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)
  New!

Find Similar Abstracts:

Use: Authors
Title
Keywords (in text query field)
Abstract Text
Return: Query Results Return    items starting with number
Query Form
Database: Astronomy
Physics
arXiv e-prints