An X-ray selected sample of radio-loud quasars
Abstract
We construct the first X-ray selected sample of broad line radio-loud AGN from the EMSS survey. In order to test unifying schemes for radio-loud objects, their spectral and statistical properties (both flat and steep spectrum objects) are examined and compared with those of other samples of blazars. The X-ray selection allows us to explore properties of radio-loud quasars 10-100 weaker in the radio band than classical samples. The most convincing interpretation of our results is that there are no radio-loud quasars whose synchrotron emission peak reaches the EUV-soft X-ray band at these (radio) flux levels. Moreover, due to the comparatively weak non-thermal emission, a quasi-thermal component appears to contribute at optical-UV energies. The detection of sources at low radio fluxes also reveals a large population of steep spectrum quasars and the lack of the predicted turnover in the quasar (radio) counts. The evolution of X-ray selected radio-loud quasars does not significantly differ from that of radio-selected ones, and flat spectrum and steep spectrum sources appear to behave quite similarly.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- May 2001
- DOI:
- 10.1051/0004-6361:20010415
- arXiv:
- arXiv:astro-ph/0103394
- Bibcode:
- 2001A&A...371..527W
- Keywords:
-
- GALAXIES: ACTIVE;
- GALAXIES: EVOLUTION;
- GALAXIES: LUMINOSITY FUNCTION;
- QUASARS: GENERAL;
- RADIO CONTINUUM: GALAXIES;
- X-RAYS: GALAXIES;
- Astrophysics
- E-Print:
- 11 pages, 10 figures, accepted for publication in Astronomy &