X-ray properties of high-redshift quasi-stellar objects

Journal Article · Sun Mar 01 04:00:00 EST 1987 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/165044· OSTI ID:6468996

Anderson, S F; Margon, B

Sensitive X-ray information is presented for about 90 previously uncataloged high-redshift, optically selected QSOs. Two high-redshift subsets of this larger data base are emphasized: (1) a complete sample of 37 objects with z = 1.8 - 3.0, and B of 19.5 or less and (2) a sample of 78 QSOs that span a narrow range in redshift and optical luminosity. From the complete sample, it is inferred that such QSOs contribute less than 3 percent to the diffuse X-ray background (XRB), and that the contribution of all QSOs with B of 19.5 or less to the XRB is 21 + or - 8 percent. For the narrow sample, it is found that the mean X-ray to optical luminosity ratio is characterized by alpha(eff)ox = 1.50 + or - 0.03. A variety of new, model-independent, empirical evidence is presented that the primary dependence of alpha(ox) is on optical luminosity rather than redshift. It is concluded that QSOs can supply as much as 70 percent of the XRB, with the typical contributor a moderate redshift QSO with B of roughly 19-21. 79 references.

• Research Organization: Washington Univ., Seattle
• OSTI ID: 6468996
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 314; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BACKGROUND RADIATION
COSMIC RADIO SOURCES
COSMIC RAY SOURCES
COSMIC X-RAY SOURCES
ELECTROMAGNETIC RADIATION
IONIZING RADIATIONS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
QUASARS
RADIATIONS
RED SHIFT
X RADIATION