Continuum energy distribution of quasars - Shapes and origins

Journal Article · Fri Dec 01 04:00:00 EST 1989 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/168094· OSTI ID:7148732

Sanders, D B; Phinney, E S; Neugebauer, G; Soifer, B T; Matthews, K ^[1]

---

1. Palomar Observatory, Pasadena, CA (USA)

Continuum observations from 0.3 nm to 6 cm are presented for 109 optically selected quasars from the Palomar-Green (PG) Bright Quasar Survey. The far-infrared to soft X-ray continuum of radio-quiet and steep-spectrum radio-loud PG quasars can be described in a model consisting of two broad peaks: an infrared bump at about 2 microns to 1 mm and the well-known big blue bump at about 10 nm to 0.3 micron. All PG quasars emit a significant fraction of their bolometric luminosity at infrared wavelengths of 1.5-100 microns. The fraction varies from 10 to 50 percent with a typical value of 30 percent. The ratio of the 6 cm flux density to that at 1 micron has a bimodal distribution. There is no evidence for a tight correlation between the infrared and X-ray continua of quasars. It is suggested that the bulk of the emission between 2 microns and 1 mm in the infrared bump of the radio-quiet PG quasars and the radio-loud quasars with steep radio spectral indices is produced by thermal processes. 117 refs.

• OSTI ID: 7148732
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 347; ISSN ASJOA; ISSN 0004-637X
• 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
ACCRETION DISKS
COSMIC RADIO SOURCES
ELECTROMAGNETIC RADIATION
ENERGY SPECTRA
GALAXIES
INFRARED RADIATION
INFRARED SPECTRA
IONIZING RADIATIONS
LUMINOSITY
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
QUASARS
RADIATIONS
SEYFERT GALAXIES
SOFT X RADIATION
SPECTRA
SURVEYS
X RADIATION