The Repeating Flaring Activity of Blazar AO 0235+164

Abstract

Context. Blazar AO 0235+164, located at redshift z = 0.94, has undergone several sharp multi-spectral-range flaring episodes during the last decades. In particular, the episodes peaking in 2008 and 2015, that received extensive multi-wavelength coverage, exhibited interesting behavior. Aims. We study the actual origin of these two observed flares by constraining the properties of the observed photo-polarimetric variability, those of the broad-band spectral energy-distribution and the observed time-evolution behavior of the source as seen by ultra-high resolution total-flux and polarimetric Very-long-baseline interferometry (VLBI) imaging. Methods. The analysis of VLBI images allows us to constrain kinematic and geometrical parameters of the 7 mm jet. We use the Discrete Correlation Function to compute the statistical correlation and the delays between emission at different spectral ranges. Multi-epoch modeling of the spectral energy distributions allows us to propose specific models of emission; in particular for the unusual spectral features observed in this source in the X-ray region of the spectrum during strong multi spectral-range flares. Results. We find that these X-ray spectral features can be explained by an emission component originating in a separate particle distribution than the one responsible for the two standard blazar bumps. This is in agreement with the results of our correlation analysis that do not find a strong correlation between the X-rays and the remaining spectral ranges. We find that both external Compton dominated and synchrotron self-Compton dominated models can explain the observed spectral energy distributions. However, synchrotron self-Compton models are strongly favored by the delays and geometrical parameters inferred from the observations.

References in corpus (36)

• The Swift X-ray Telescope
• The Swift Ultra-Violet/Optical Telescope
• Methods and results of an automatic analysis of a complete sample of Swift-XRT observations of GRBs
• The Burst Alert Telescope (BAT) on the Swift MIDEX Mission
• Photometric Calibration of the Swift Ultraviolet/Optical Telescope
• Relativistic Jets in Active Galactic Nuclei
• Polarimetric Observations of 15 Active Galactic Nuclei at High Frequencies: Jet Kinematics from Bimonthly Monitoring with the Very Long Baseline Array
• Studies in Astronomical Time Series Analysis. VI. Bayesian Block Representations
• Probing the Inner Jet of the Quasar PKS 1510-089 with Multi-waveband Monitoring during Strong Gamma-ray Activity
• Reverberation Mapping of High-Luminosity Quasars: First Results
• Multi-Epoch VLBA Observations of EGRET-Detected Quasars and BL Lac Objects: Superluminal Motion of Gamma-Ray Bright Blazars
• Gamma-ray Light Curves and Variability of Bright Fermi-Detected Blazars
• Swift observations of the very intense flaring activity of Mrk 421 during 2006: I. Phenomenological picture of electron acceleration and predictions for the MeV/GeV emission
• Stochastic Acceleration and the Evolution of Spectral Distributions in SSC Sources: A Self Consistent Modeling of Blazars' Flares
• On the Reliability of Cross Correlation Function Lag Determinations in Active Galactic Nuclei
• Synchrotron Self-Compton Model for Rapid Nonthermal Flares in Blazars with Frequency-Dependent Time Lags
• Spitzer Observations of 3C Quasars and Radio Galaxies: Mid-Infrared Properties of Powerful Radio Sources
• Jet stability and the generation of superluminal and stationary components
• Kinematics of Parsec-Scale Jets of Gamma-Ray Bright Blazars at 43 GHz during Ten Years of the VLBA-BU-BLAZAR Program
• On the Location of the Gamma-ray Emission in the 2008 Outburst in the BL Lacertae Object AO 0235+164 through Observations across the Electromagnetic Spectrum
• Dust and Diffuse Interstellar Bands in the z_a = 0.524 Absorption System toward AO 0235+164
• Erratic Jet Wobbling in the BL Lacertae Object OJ287 Revealed by Sixteen Years of 7mm VLBA Observations
• Probing Acceleration and Turbulence at Relativistic Shocks in Blazar Jets
• POLAMI: Polarimetric Monitoring of Active Galactic Nuclei at Millimetre Wavelengths. I. The program, calibration, and calibrators data products
• POLAMI: Polarimetric Monitoring of Active Galactic Nuclei at Millimetre Wavelengths. III. Characterisation of total flux density and polarisation variability of relativistic jets
• A multi-wavelength polarimetric study of the blazar CTA 102 during a Gamma-ray flare in 2012
• Bulk Comptonization spectra in blazars
• Multi-wavelength observations of blazar AO 0235+164 in the 2008-2009 flaring state
• Radio-to-UV monitoring of AO 0235+164 by the WEBT and Swift during the 2006--2007 outburst
• POLAMI: Polarimetric Monitoring of Active Galactic Nuclei at Millimetre Wavelengths. II. Widespread circular polarisation
• The extreme blazar AO 0235+164 as seen by extensive ground and space radio observations
• Radio$-\gamma -$ray response in blazars as a signature of adiabatic blob expansion
• A comprehensive study on the variation phenomena of AO 0235+164
• On the distribution of fluxes of gamma-ray blazars: hints for a stochastic process?
• The RoboPol Program: Optical Polarimetric Monitoring of Blazars
• Monte-Carlo Applications for Partially Polarized Inverse External-Compton Scattering (MAPPIES) II -- Application to the UV/Soft X-ray Excess in Blazar Spectra

Cited by in corpus (1)

• The flaring activity of blazar AO 0235+164 during year 2021