CGRO, radio and optical observations of the quasar NRAO 140.
Abstract
We report on Compton Gamma Ray Observatory (CGRO), radio and optical observations of the radio-loud, superluminal quasar NRAO 140. The source is not detected (significance 3σ) by any of the CGRO instruments OSSE, Comptel and EGRET. Radio observations simultaneous to the OSSE observation and optical monitoring over three-monthly intervals show no signs of extraordinary behaviour when compared to previous observations. We demonstrate that the CGRO non-detections do not require a spectral break at hard X-rays, but can be explained by a steep spectrum in the MeV range comparable to that of 3C 273.
- Publication:
-
Astronomy and Astrophysics Supplement Series
- Pub Date:
- December 1996
- DOI:
- arXiv:
- arXiv:astro-ph/9609002
- Bibcode:
- 1996A&AS..120C.533M
- Keywords:
-
- GALAXIES: ACTIVE;
- GAMMA RAYS: OBSERVATIONS;
- QUASARS: INDIVIDUAL: NRAO 140;
- Astrophysics
- E-Print:
- to appear in A&