The Physical Properties of Changing-look Blazars

Abstract

Changing-look active galactic nuclei (AGNs) are a special class of AGNs that change their spectral type from type 1 to type 2 or vice versa. In recent years, a number of changing-look blazars (CLBs) were also reported, which transition between flat-spectrum radio quasars and BL Lacs. The physical properties of CLBs are still unclear. Using the $mclust$ R package for Gaussian Mixture Modeling, we performed a clustering analysis for a sample of 105 CLBs selected from the literature. Three kinds of analysis found that CLBs lie in between the parameter distributions of FSRQs and BL Lacs: (i) univariate analysis; (ii) bivariate analysis; and (iii) multivariate analysis, carried out with a dimension reduction approach of the physical properties of the three types of blazars. Our results suggest that CLBs belong to a transition type between FSRQs and BL Lacs, which may be regulated by the change of accretion process and may be similar to other changing-look AGNs.

Published in ApJ. 8 pages, 3 figures, 1 table

References in corpus (36)

• Unified Schemes for Radio-Loud Active Galactic Nuclei
• Hot Accretion Flows Around Black Holes
• A Unifying View of the Spectral Energy Distributions of Blazars
• A theoretical unifying scheme for gamma-ray bright blazars
• Incremental Fermi Large Area Telescope Fourth Source Catalog
• Detecting Bimodality in Astronomical Datasets
• The transition between BL Lac objects and Flat Spectrum Radio Quasars
• A simplified view of blazars: clearing the fog around long-standing selection effects
• The Fermi blazar sequence
• The Cosmic Evolution of Fermi BL Lacertae Objects
• Spectroscopy of Broad Line Blazars from 1LAC
• An evolutionary scenario for blazar unification
• TXS 0506+056, the first cosmic neutrino source, is not a BL Lac
• The Fourth Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope -- Data Release 3
• A Statistical Approach to Recognizing Source Classes for Unassociated Sources in the First Fermi-LAT Catalog
• The Central Engines of Fermi Blazars
• Multi-color optical monitoring of the quasar 3C 273 from 2005 to 2016
• Optical Spectroscopic Observations of Gamma-ray Blazar Candidates. V. TNG, KPNO, and OAN Observations of Blazar Candidates of Uncertain Type in the Northern Hemisphere
• Blue Fermi Flat Spectrum Radio Quasars
• The Blazar sequence and its Physical Understanding
• The Relativistic Jet Dichotomy and the End of the Blazar Sequence
• A New Sample of Gamma-Ray Emitting Jetted Active Galactic Nuclei
• The Nature of Transition Blazars
• An accretion disk-outflow model for hysteretic state transition in X-ray binaries
• Basic properties of Fermi blazars and the "blazar sequence"
• WISE view of changing-look AGNs: evidence for a transitional stage of AGNs
• An optical overview of blazars with LAMOST I: Hunting changing-look blazars and new redshift estimates
• The Changing Look Blazar B2 1420+32
• The Estimation of Fundamental Physics Parameters for Fermi-LAT Blazars
• Radio-Gamma-ray connection and spectral evolution in 4C +49.22 (S4 1150+49): the Fermi, Swift and Planck view
• An extensive study of blazar broad emission line: Changing-look blazars and Baldwin effect
• The First Gamma-ray Emitting BL Lacertae Object at the Cosmic Dawn
• Accretion Disk MHD Winds and Blazar Classification
• The changing look of PKS 2149-306
• FSRQ/BL Lac dichotomy as the magnetized advective accretion process around black holes: a unified classification of blazars
• Are many radio-selected BL Lacs radio quasars in disguise?

Cited by in corpus (2)

• The Energy Budget in the Jet of High-frequency Peaked BL Lacertae Objects
• The Fermi-LAT view of the changing-look blazar OQ 334