| Autor: |
Paul Francis, Jack A. Baldwin, Hagai Netzer, K. L. Thompson, Beverley J. Wills, Michael S. Brotherton, Derek Wills, Robert F. Carswell, Ian Browne |
| Rok vydání: |
1997 |
| Předmět: |
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| Zdroj: |
International Astronomical Union Colloquium. 159:104-105 |
| ISSN: |
0252-9211 |
| Popis: |
We have obtained HST and ground-based spectrophotometry of a sample of ~61 radio-loud quasars from shortward of Lyα to longward of Hβ. The aim was to investigate the dependence of quasar properties on orientation of the central engine axis to the observer’s line of sight. As an approximate measure of inclination we use the radio core-dominance, i.e., the ratio of beamed radiocore emission to the emission in the extended lobes at 5 GHz rest frequency. About half the radio sources have core-dominance greater than unity (jet or axis pointed close to our line of sight). Quasar pairs were matched in radio lobe luminosity and redshift to reduce bias caused by strong dependences on intrinsic luminosity.Observation and reduction techniques were standard, and the spectral resolution is equivalent to 230–400 km s−1 (Wills et al. 1993). We have performed correlation analyses among emission-line and continuum parameters, as well as spectral principal-component analyses (SPCA, Francis et al. 1992). |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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