The Baldwin effect and the Mg II - 3000 Å luminosity relation in blazars
Abstract
We present a re-evaluation of the relationship between the Mg II λ2798 Å emission line and the 3000 Å continuum luminosity, including an analysis of the Baldwin Effect, using a sample of 40,685 radio-quiet quasars and 441 Flat Spectrum Radio Quasars (FSRQs).To address dispersion from AGN variability, we applied a binning technique after excluding over 3,000 radioloud sources, resulting in a refined empirical correlation.Our findings reveal statistically significant differences in the slope of this relationship between RQ quasars and FSRQs, implying either intrinsic differences in their accretion disk spectra or a significant contribution from jet-induced continuum to the BLR ionization in FSRQs.Furthermore, our investigation of the Non-Thermal Dominance (NTD) parameter shows that a substantial fraction of both populations (43.8% of RQ quasars and 55.5% of blazars) exhibit N T D < 1.We interpret this in blazars as evidence that the accretion disk alone cannot power the BLR, while in RQ quasars, it may indicate BLR anomalies, continuum-line time lags, or UV continuum suppression by a strong corona.Finally, we demonstrate that the Baldwin Effect is a direct consequence of the fundamental line-continuum luminosity relationship.
Fields of Study & Subjects
Galaxies: Formation
Evolution
Phenomena
Astrophysical Phenomena and Observations
Astrophysics and Cosmic Phenomena
Publication details
- Journal / source
- Contributions of the Astronomical Observatory Skalnaté Pleso
- Volume
- 56
- Issue
- 1
- Publication date
- 1 January 2026