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Nearly simultaneous optical, ultraviolet, and x ray observations of three pg quasars
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Kriss, Gerard A. |
| Copyright Year | 1990 |
| Description | 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. |
| File Size | 745378 |
| Page Count | 19 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19900010616 |
| Archival Resource Key | ark:/13960/t8hf2r437 |
| Language | English |
| Publisher Date | 1990-03-08 |
| Access Restriction | Open |
| Subject Keyword | Astronomy Quasars Seyfert Galaxies Red Shift X Rays Stellar Mass Exosat Satellite Visual Observation Ultraviolet Spectra Luminosity X Ray Spectra Accretion Disks Black Holes Astronomy Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
