Internal shocks and the blazar sequence. Low and intermediate power BL Lac objects

Abstract

We consider internal shocks as the main dissipation mechanism responsible for the emission in blazars and show that it can satisfactorily account for the properties of all blazars. In particular, we extend previous work (Spada et al. 2001) on powerful objects, to intermediate (BL Lac) and low power sources (Mkn 421), in order to reproduce the whole of the blazar sequence. The model self-consistently treats the dynamics, spectral emission and its variability. The key parameters driving the phenomenological sequence are the jet power and the properties of the broad line region, which regulate the cooling efficiency of the emitting particles and thus the shape of the spectral energy distribution. By assuming that the remaining parameters are similar for all objects it has been possible to reproduce the full range of the observed spectral "states". A more detailed comparison of the variability properties shows (for Mkn 421) a good agreement in the X-ray band, while in the optical the simulated flux appears to be too variable. For BL Lac lags (~10 days) are predicted between the gamma--rays and the infrared emission

10 pages, 12 figures. Submitted to Astronomy and Astrophysics

References in corpus (20)

• Reverberation Measurements for 17 Quasars and the Size-Mass-Luminosity Relations in Active Galactic Nuclei
• A Unifying View of the Spectral Energy Distributions of Blazars
• Unsteady Outflow Models for Cosmological Gamma-Ray Bursts
• A theoretical unifying scheme for gamma-ray bright blazars
• Gamma-ray bursts from internal shocks in a relativistic wind: temporal and spectral properties
• Internal shocks in the jets of radio-loud quasars
• Large scale jets in AGN: multiwavelength mapping
• TeV candidate BL Lac objects
• On the Efficiency of Internal Shocks in Gamma-Ray Bursts
• Efficiency and spectrum of internal gamma-ray burst shocks
• Dynamical Evolution, Light-Curves and Spectra of Spherical and Collimated Gamma-Ray Burst Remnants
• What Types of Jets does Nature Make: A New Population of Radio Quasars
• On the Nature of MeV-blazars
• Variability Time Scales of TeV Blazars Observed in the ASCA Continuous Long-Look X-ray Monitoring
• Analysis of Temporal Features of Gamma Ray Bursts in the Internal Shock Model
• Observations of a Correlated Gamma-Ray and Optical Flare for BL Lacertae
• Constraints on the bulk Lorentz factor in the internal shock scenario for gamma-ray bursts
• BL Lacertae: complex spectral variability and rapid synchrotron flare detected with BeppoSAX
• Implications of Variability Patterns observed in TeV Blazars on the Structure of the Inner Jet
• BeppoSAX and multiwavelength observations of BL Lacertae in 2000

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• Optical Monitoring of BL Lac Object S5 0716+714 with High Temporal Resolution
• A rapid and dramatic outburst in Blazar 3C 454.3 during May 2005 - Optical and infrared observations with REM and AIT
• TeV variability in blazars: how fast can it be?
• VLBA Polarization Observations of Markarian 421 After a Gamma-Ray High State
• Long-term variability of extragalactic radio sources in the Planck Early Release Compact Source Catalogue
• Multi-band optical variability of 3C 279 on diverse timescales
• Particle diffusion and localized acceleration in inhomogeneous AGN jets - Part II: stochastic variation
• Broad Ly alpha Emission from Three Nearby BL Lacertae Objects
• Multi-frequency properties of synthetic blazar radio light curves within the shock-in-jet scenario
• The Fermi/LAT sky as seen by INTEGRAL/IBIS
• Extragalactic Gamma--Rays: Gamma Ray Bursts and Blazars