Sign on
ADS Classic is now deprecated. It will be completely retired in October 2019. Please redirect your searches to the new ADS modern form or the classic form. More info can be found on our blog.

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 (127) (Citation History)
· Refereed Citations to the Article
· NED Objects (56)
· Reads History
·
· Translate This Page
Title:
A complete sample of quasars at B = 19.80
Authors:
Marshall, H. L.; Avni, Y.; Braccesi, A.; Huchra, J. P.; Tananbaum, H.; Zamorani, G.; Zitelli, V.
Affiliation:
AA(Harvard-Smithsonian Center for Astrophysics, Cambridge, MA), AB(Harvard-Smithsonian Center for Astrophysics, Cambridge, MA), AC(Harvard-Smithsonian Center for Astrophysics, Cambridge, MA), AD(Harvard-Smithsonian Center for Astrophysics, Cambridge, MA; Weizmann Institute of Science, Rehovot, Israel), AE(Bologna, Università; Osservatorio, Astronomico, Bologna, Italy), AF(Bologna, Università; Osservatorio, Astronomico, Bologna, Italy), AG(Harvard-Smithsonian Center for Astrophysics, Cambridge, MA; CNR, Istituto di Radioastronomia, Bologna, Italy)
Publication:
Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 283, Aug. 1, 1984, p. 50-58. Research supported by the Consiglio Nazionale delle Ricerche. (ApJ Homepage)
Publication Date:
08/1984
Category:
Astrophysics
Origin:
STI
NASA/STI Keywords:
Astronomical Catalogs, Data Sampling, Quasars, Ultraviolet Astronomy, X Ray Sources, Emission Spectra, Luminosity, Optical Measurement, Red Shift
DOI:
10.1086/162272
Bibliographic Code:
1984ApJ...283...50M

Abstract

A quasar candidate spectroscopic UV-excess survey with B less than 19.80 has yielded 35 quasars in the 1.75 sq deg region studied. The X-ray data for the 35 quasars are used to show that quasars with B lower than 19.80 and z lower than 2.2 constitute 24 + 10, -8 percent of the observed X-ray background at 2 keV. This sample is combined with one containing 22 quasars with B values lower than 18.25, and it is noted that fits of evolution and luminosity functions are substantially similar to previous results, although the confidence limits for the model parameters are reduced by a factor of 2. Pure luminosity evolution models are found to produce very good fits to the observed N(less than B) data, and are used to estimate the overall contribution of quasars to the X-ray background.

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