On the correlation between radio and gamma ray luminosities of active galactic nuclei.
Abstract
The possibility of a correlation between the radio (cm) and γray luminosity of variable AGN seen by EGRET is investigated. We perform MonteCarlo simulations of typical data sets and apply different correlation techniques (partial correlation analysis, χ^2^test applied on fluxflux relations) in view of a truncation bias caused by sensitivity limits of the surveys. For Kcorrected flux densities, we find that with the least squares method only a linear correlation can be recovered. Partial correlation analysis on the other side provides a robust tool to detect correlations even in fluxlimited samples if intrinsic scatter does not exceed ~40% of the original γray luminosity. However, if mean flux values of high variable sources are used we find the chance probability of high Spearman's correlation coefficient be significant underestimated. The analysis presented in this paper takes into account redshift bias and truncation effects simultaneously which was never considered in earlier papers. Applying this analysis to simultaneously observed radio and γray data, no correlation is found. However, an artificial correlation appears when using the mean flux. This is probably due to the reduction of the dynamical range in the fluxflux relation. Furthermore, we show that comparing the emission in both spectral bands at a high activity state leads to no convincing correlation. In conclusion, we cannot confirm a correlation between radio and γray luminosities of AGN which is claimed in previous works.
 Publication:

Astronomy and Astrophysics
 Pub Date:
 April 1997
 DOI:
 10.48550/arXiv.astroph/9602113
 arXiv:
 arXiv:astroph/9602113
 Bibcode:
 1997A&A...320...33M
 Keywords:

 GALAXIES: ACTIVE;
 QUASARS: GENERAL;
 GAMMA RAYS: OBSERVATIONS;
 METHODS: STATISTICAL;
 Astrophysics
 EPrint:
 8 pages, 4 figures, uuencoded + gzipped, latex. Submitted to A&