X-ray quasars

Conference · Tue Jan 01 04:00:00 EST 1980 · Ann. N.Y. Acad. Sci.; (United States)

OSTI ID:5080644

Bradt, H V

Observational data for the seven quasars or Seyfert-quasar transition objects identified with X-ray sources is reviewed for radio, infrared, optical, ultraviolet, X-ray and gamma-ray frequencies. The observational histories of the quasars 3C 273, MR 2251-178 and 0241+622 and the quasar-like Seyfert nuclei Fairall-9, Mk 509, IC 4329A and IIIZw 2 are discussed in detail, and it is noted that their X-ray variability and spectra do not differentiate them from Seyfert nuclei, supporting the similarity between the several types of active extragalactic nuclei. The space density of the six objects (excluding 3C 273) within 600 Mpc is found to be comparable to that of other Seyferts and quasars, suggesting that X-ray emitting objects constitute a substantial fraction of the luminous transition objects in the neighborhood of the Galaxy. It is also pointed out that observations of the X-ray variability of these objects, which indicates that the X-rays originate from compact regions, represent a promising means for the further understanding of the emission process.

• Research Organization: MIT, Cambridge, Mass.
• OSTI ID: 5080644
• Report Number(s): CONF-781245-
• Conference Information: Journal Name: Ann. N.Y. Acad. Sci.; (United States) Journal Volume: 336
• Country of Publication: United States
• Language: English

Related Subjects

640103* -- Astrophysics & Cosmology-- Quasi-Stellar
Radio
& X-Ray Sources-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ASTRONOMY
COSMIC RADIO SOURCES
COSMIC RAY SOURCES
COSMIC X-RAY SOURCES
ELECTROMAGNETIC RADIATION
GALAXIES
GALAXY NUCLEI
GAMMA SPECTRA
INFRARED SPECTRA
MILKY WAY
QUASARS
RADIATIONS
RADIOASTRONOMY
SEYFERT GALAXIES
SPECTRA
SPECTROSCOPY
ULTRAVIOLET SPECTRA
VISIBLE RADIATION
X-RAY SPECTROSCOPY