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)
· On-line Data
· References in the article
· Citations to the Article (127) (Citation History)
· Refereed Citations to the Article
· SIMBAD Objects (142)
· NED Objects (143)
· Associated Articles
· Also-Read Articles (Reads History)
· HEP/Spires Information
·
· Translate This Page
Title:
The Hubble Space Telescope Quasar Absorption Line Key Project. 10: Galactic H I 21 centimeter emission toward 143 quasars and active Galactic nuclei
Authors:
Lockman, Felix J.; Savage, Blair D.
Affiliation:
AA(National Radio Astronomy Observatory, Green Bank, WV, US), AB(National Radio Astronomy Observatory, Green Bank, WV, US)
Publication:
Astrophysical Journal Supplement Series (ISSN 0067-0049), vol. 97, no. 1, p. 1-47 (ApJS Homepage)
Publication Date:
03/1995
Category:
Astronomy
Origin:
STI
NASA/STI Keywords:
ACTIVE GALACTIC NUCLEI, EMISSION SPECTRA, HYDROGEN, INTERSTELLAR EXTINCTION, INTERSTELLAR GAS, LINE SPECTRA, QUASARS, RADIO ASTRONOMY, ULTRAVIOLET ABSORPTION, DENSITY (MASS/VOLUME), GALACTIC HALOS, HUBBLE SPACE TELESCOPE, MILKY WAY GALAXY, RADIO TELESCOPES, ULTRAVIOLET ASTRONOMY, VELOCITY
DOI:
10.1086/192133
Bibliographic Code:
1995ApJS...97....1L

Abstract

Sensitive H I 21 cm emission line spectra have been measured for the directions to 143 quasars and active galactic nuclei (AGNs) chosen from the observing lists for the Hubble Space Telescope (HST) Quasar Absorption Line Key Project. Narrow-band and wide-band data were obtained with the National Radio Astronomy Observatory (NRAO) 43 m radio telescope for each object. The narrow-band data have a velocity resolution of 1 km/s, extend from -220 to +170 km/s, and are corrected for stray 21 cm radiation. The wide-band data have a resolution of 4 km/s and extend from -1000 to +1000 km/s. The data are important for the interpretation of ultraviolet absorption lines near zero redshift in Key Project spectra. Twenty-two percent of the quasars lie behind Galactic high-velocity H I clouds with absolute value of VLSR greater than 100 km/s whose presence can increase the equivalent width of interstellar absorption lines significantly. This paper contains the emission spectra and measures of the H I velocities and column densities along the sight line to each quasar. We discuss how the measurements can be used to estimate the visual and ultraviolet extinction toward each quasar and to predict the approximate strength of the strong ultraviolet resonance lines of neutral gas species in the HST Key Project spectra.

Associated Articles

Part  3     Part 1     Part  2     Part  4     Part 11     Part  6     Part  8     Part 10     Part  5     Part 12     Part  7     Part 13     Catalog Description     Part 15     Part 14     Part 16    

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)
   

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