Nearly simultaneous optical, ultraviolet, and x ray observations of three PG quasars. Final technical report

Technical Report · Thu Mar 01 04:00:00 EST 1990

OSTI ID:6770434

Kriss, G A

Nearly simultaneous optical, ultraviolet, and x ray observations of three low redshift quasars are presented. The EXOSAT x ray spectra span the range of observed spectral indices for quasars from the canonical 0.7 energy index typical of Seyfert galaxies for PG0923+129 (Mrk 705) to the steep spectral indices frequently seen in higher luminosity quasars with an index of 1.58 for PG0844+349 (Ton 951). None of the quasars exhibits any evidence for a soft x ray excess. This is consistent with accretion disk spectra fit to the IR through UV continua of the quasars -- the best fitting disk spectra peak at approximately 6 eV with black hole masses in the range 5 x 10(exp 7) to 1 x 10(exp 9) solar mass and mass accretion rates of approximately 0.1 times the Eddington-limited rate. These rather soft disk spectra are also compatible with the observed optical and ultraviolet line ratios.

• Research Organization: Johns Hopkins Univ., Baltimore, MD (USA)
• OSTI ID: 6770434
• Report Number(s): N-90-19932; NASA-CR--186355; NAS--1.26:186355
• 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
BLACK HOLES
COSMIC RADIO SOURCES
DATA
DOCUMENT TYPES
EXPERIMENTAL DATA
GALAXIES
INFORMATION
LUMINOSITY
NUMERICAL DATA
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
PROGRESS REPORT
QUASARS
RED SHIFT
SEYFERT GALAXIES
SPECTRA
ULTRAVIOLET SPECTRA
X-RAY SPECTRA