On the BL Lacertae objects/radio quasars and the FRI/II dichotomy

Abstract

In the frame of unification schemes for radio-loud active galactic nuclei (AGNs), FR I radio galaxies are believed to be BL Lacertae (BL Lac) objects with the relativistic jet misaligned to our line of sight, and FR II radio galaxies correspond to misaligned radio quasars. The Ledlow-Owen dividing line for FR I/FR II dichotomy in the optical absolute magnitude of host galaxy-radio luminosity (M_R-L_Rad) plane can be translated to the line in the black hole mass-jet power (M_bh-Q_jet) plane by using two empirical relations: Q_jet-L_Rad and M_bh}-M_R. We use a sample of radio quasars and BL Lac objects with measured black hole masses to explore the relation of the jet power with black hole mass, in which the jet power is estimated from the extended radio emission. It is found that the BL Lac objects are clearly separated from radio quasars by the Ledlow & Owen FR I/II dividing line in the M_bh-Q_jet plane. This strongly supports the unification schemes for FR I/BL Lac object and FR II/radio quasar. We find that the Eddington ratios L_bol/L_Edd of BL Lac objects are systematically lower than those of radio quasars in the sample with a rough division at L_bol/L_Edd 0.01, and the distribution of Eddington ratios of BL Lac objects/quasars exhibits a bimodal nature, which imply that the accretion mode of BL Lac objects may be different from that of radio quasars.

4 pages, 2 figures, accepted by ApJL

References in corpus (6)

• Radio-Loudness of Active Galactic Nuclei: Observational Facts and Theoretical Implications
• Hot and cold gas accretion and feedback in radio-loud active galaxies
• Multi-colour optical monitoring of eight red blazars
• Optical spectroscopy of BL Lacertae objects. Broad lines, companion galaxies and redshift lower limits
• Jet power extracted from ADAF and the applications to X-ray binaries and radio galaxy FR dichotomy
• On the relationship between BL Lacertae objects and radio galaxies

Cited by in corpus (17)

• Constraints on minimum electron Lorentz factor and matter content of jets for a sample of bright Fermi blazars
• The curvature of spectral energy distribution of blazars
• Analytical Solution of Magnetically Dominated Astrophysical Jets and Winds: Jet Launching, Acceleration, and Collimation
• The high efficiency jets magnetically accelerated from a thin disk in powerful lobe-dominated FRII radio galaxies
• Jet Power of Jetted Active Galactic Nuclei: Implication for Evolution and Unification
• Evaluating the classification of Fermi BCUs from the 4FGL Catalog Using Machine Learning
• M87: a cosmic laboratory for deciphering black hole accretion and jet formation
• Search for intra-day optical variability in Mrk 501
• The Origin of High Energy Emission in the Young Radio Source PKS 1718-649
• Kinetic powers of the relativistic jets in Mrk 421 and Mrk 501
• Correlations between $\gamma$-ray luminosity and magnetization of the jet as well as relativistic electron injection power:cases for Mrk 421, 3C 454.3 and 3C 279
• Observational evidences for spinning black holes: A proof of general relativity for spacetime around rotating black holes
• The beaming effect for Fermi-LAT-detected FR-I radio galaxies
• Modelling radio luminosity functions of radio-loud AGN by the cosmological evolution of supermassive black holes
• The Accretion Properties and Jet Mechanisms for the Low-Excitation Radio Galaxies
• Linking {\it Fermi} blazars and radio galaxies through accretion and jet radiation mechanisms
• AGN jets under the microscope: A divide?