Models for high-frequency radio outbursts in extragalactic sources, with application to the early 1983 millimeter-to-infrared flare of 3C 273

Marscher, A. P.; Gear, Walter Kieran

doi:10.1086/163592

Cited by 1,189 publications

(1,279 citation statements)

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“…The seed photons are most likely the synchrotron photons internal to the jet. Such "synchrotron selfCompton" (SSC) models, developed by many authors (for early examples see, e.g., Jones et al 1974;Ghisellini et al 1985;Marscher & Gear 1985), have been successfully invoked to describe the full SED of HBL objects (e.g., Ulrich et al 1997;Fossati et al 2008;Tavecchio et al 2010).…”

Section: Introductionmentioning

confidence: 99%

MULTIWAVELENGTH STUDY OF QUIESCENT STATES OF Mrk 421 WITH UNPRECEDENTED HARD X-RAY COVERAGE PROVIDED BY NuSTAR IN 2013

Baloković¹,

Paneque²,

Madejski³

et al. 2016

ApJ

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110

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We present coordinated multiwavelength observations of the bright, nearby BL Lacertae object Mrk 421 taken in 2013 January-March, involving GASP-WEBT, Swift, NuSTAR, Fermi-LAT, MAGIC, VERITAS, and other collaborations and instruments, providing data from radio to very high energy(VHE) γ-ray bands. NuSTAR yielded previously unattainable sensitivity in the 3-79keV range, revealing that the spectrum softens when the source is dimmer until the X-ray spectral shape saturates into a steep 3 G » power law, with no evidence for an exponential cutoff or additional hard components up to ∼80keV. For the first time, we observed both the synchrotron and the inverse-Compton peaks of the spectral energy distribution (SED) simultaneously shifted to frequencies below the typical quiescent state by an order of magnitude. The fractional variability as a function of photon energy shows a double-bump structure that relates to the two bumps of the broadband SED. In each bump, the variability increases with energy, which, in the framework of the synchrotron self-Compton model, implies that the electrons with higher energies are more variable. The measured multi band variability, the significant X-ray-to-VHE correlation down to some of the lowest fluxes ever observed in both bands, the lack of correlation between optical/UV and X-ray flux, the low degree of polarization and its significant (random) variations, the short estimated electron cooling time, and the significantly longer variability timescale observed in the NuSTAR light curves point toward in situ electron acceleration and suggest that there are multiple compact regions contributing to the broadband emission of Mrk 421 during low-activity states.

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Section: Introductionmentioning

confidence: 99%

MULTIWAVELENGTH STUDY OF QUIESCENT STATES OF Mrk 421 WITH UNPRECEDENTED HARD X-RAY COVERAGE PROVIDED BY NuSTAR IN 2013

Baloković¹,

Paneque²,

Madejski³

et al. 2016

ApJ

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110

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“…Several papers have demonstrated that the observed polarization signatures may indicate a helical magnetic structure (Lyutikov et al 2005;Pushkarev et al 2005;Zhang et al 2015). The high-energy component, from X-rays to γ-rays, is usually interpreted as originating from inverse Compton scattering by the same nonthermal electrons of soft seed photons (e.g., Marscher & Gear 1985;Dermer et al 1992;Sikora et al 1994), but a hadronic origin cannot be ruled out (e.g., Mannheim & Biermann 1992;Mücke & Protheroe 2001;Böttcher et al 2013). Both spectral components of blazars exhibit fast variability.…”

Section: Introductionmentioning

confidence: 99%

“…However, in general, numerical simulations of shock acceleration do not provide detailed calculations of the expected radiation features. In terms of the spectral variability fittings, scenarios of relativistic shocks propagating through the jet have been widely investigated (e.g., Marscher & Gear 1985;Spada et al 2001;Joshi & Böttcher 2007;Graff et al 2008). These models have successfully fit the time-dependent SEDs and multiwavelength light curves of blazar flares, but they usually assume a stationary chaotic magnetic field.…”

Section: Introductionmentioning

confidence: 99%

Polarization Signatures of Relativistic Magnetohydrodynamic Shocks in the Blazar Emission Region. I. Force-Free Helical Magnetic Fields

Zhang

Deng

et al. 2016

ApJ

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The optical radiation and polarization signatures in blazars are known to be highly variable during flaring activities. It is frequently argued that shocks are the main driver of the flaring events. However, the spectral variability modelings generally lack detailed considerations of the self-consistent magnetic field evolution modeling; thus, so far the associated optical polarization signatures are poorly understood. We present the first simultaneous modeling of the optical radiation and polarization signatures based on 3D magnetohydrodynamic simulations of relativistic shocks in the blazar emission environment, with the simplest physical assumptions. By comparing the results with observations, we find that shocks in a weakly magnetized environment will largely lead to significant changes in the optical polarization signatures, which are seldom seen in observations. Hence an emission region with relatively strong magnetization is preferred. In such an environment, slow shocks may produce minor flares with either erratic polarization fluctuations or considerable polarization variations, depending on the parameters; fast shocks can produce major flares with smooth polarization angle rotations. In addition, the magnetic fields in both cases are observed to actively revert to the original topology after the shocks. All these features are consistent with observations. Future observations of the radiation and polarization signatures will further constrain the flaring mechanism and the blazar emission environment.

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“…The PA rotation simultaneous with depolarization in 2009, can be explained if the new component has a PA almost perpendicular to the jet PA. In 2011, the delay between radio and γ-ray flares can be attributed to the propagation of an expanding jet component, initially optically thick at radio frequencies, which reaches its maximum flux density when it becomes optically thin [15][16][17].…”

Section: Discussionmentioning

confidence: 99%

Optical Polarimetry and Radio Observations of PKS1510-089 between 2009 and 2013

2018

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Abstract:The blazar PKS 1510-089 has shown intense activity at γ-rays in the recent years. In this work, we discussed the results of our 7 mm radio continuum and optical polarimetric monitoring between 2009 and 2013. In 2009, we detected a large rotation of the optical polarization angle that we attributed to the ejection of new polarized components. In 2011, after the occurrence of several γ-rays flares, the radio emission started to increase, reaching values never observed before. We interpreted this increase as the consequence of the superposition of several new components ejected during the γ-rays flares. A delay was measured between the maximum in the radio emission and the γ-ray flares, which favors models involving expanding components like the shock-in-jet models. Finally, we tried to understand the polarization angle variability behavior filling the gaps in our observations with published results of other polarimetric campaigns, and using the criterion of minimum variation in the polarization angle between successive observations to solve the 180 o multiplicity.

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Models for high-frequency radio outbursts in extragalactic sources, with application to the early 1983 millimeter-to-infrared flare of 3C 273

Cited by 1,189 publications

References 0 publications

MULTIWAVELENGTH STUDY OF QUIESCENT STATES OF Mrk 421 WITH UNPRECEDENTED HARD X-RAY COVERAGE PROVIDED BY NuSTAR IN 2013

MULTIWAVELENGTH STUDY OF QUIESCENT STATES OF Mrk 421 WITH UNPRECEDENTED HARD X-RAY COVERAGE PROVIDED BY NuSTAR IN 2013

Polarization Signatures of Relativistic Magnetohydrodynamic Shocks in the Blazar Emission Region. I. Force-Free Helical Magnetic Fields

Optical Polarimetry and Radio Observations of PKS1510-089 between 2009 and 2013

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