X-ray spectral variations of synchrotron peak in BL Lacs

Abstract

The spectral energy distribution of blazars around the synchrotron peak can be well described by the log-parabolic model that has three parameters: peak energy ($E_{\text{p}}$), peak luminosity ($L_{\text{p}}$) and the curvature parameter ($b$). It has been suggested that $E_{\text{p}}$ shows relations with $L_{\text{p}}$ and $b$ in several sources, which can be used to constrain the physical properties of the emitting region and/or acceleration processes of the emitting particles. We systematically study the $E_{\text{p}}$-$L_{\text{p}}$ and $E_{\text{p}}$-(1$/b$) relations for 14 BL Lac objects using the 3-25~keV $RXTE$/PCA and 0.3-10~keV $Swift$/XRT data. Most objects (9/14) exhibit positive $E_{\text{p}}$-$L_{\text{p}}$ correlations, three sources show no correlation, and two sources display negative correlations. In addition, most targets (7/14) present no correlation between $E_{\text{p}}$ and 1$/b$, five sources pose negative correlations, and two sources demonstrate positive correlations. 1ES~1959+650 displays two different $E_{\text{p}}$-$L_{\text{p}}$ relations in 2002 and 2016. We also analyze $E_{\text{p}}$-$L_{\text{p}}$ and $E_{\text{p}}$-(1$/b$) relations during flares lasting for several days. The $E_{\text{p}}$-$L_{\text{p}}$ relation does not exhibit significant differences between flares, while the $E_{\text{p}}$-(1$/b$) relation varies from flare to flare. For the total sample, when $L_{\text{p}}$ < ${\text{10}}^{\text{45}}\text{erg}{\text{s}}^{\text{-1}}$, there seems to be a positive $E_{\text{p}}$-$L_{\text{p}}$ correlation. $L_{\text{p}}$ and the slope of $E_{\text{p}}$-$L_{\text{p}}$ relation present an anti-correlation, which indicates that the causes of spectral variations might be different between luminous and faint sources. $E_{\text{p}}$ shows a positive correlation with the black hole mass. We discuss the implications of these results.

arXiv comment19 pages, 10 figures, 2 tables; Accepted for publication in ApJ

References in corpus (45)

• Planck 2015 results. XIII. Cosmological parameters
• Unified Schemes for Radio-Loud Active Galactic Nuclei
• Some Aspects of Measurement Error in Linear Regression of Astronomical Data
• A Unifying View of the Spectral Energy Distributions of Blazars
• The Spectral Energy Distribution of Fermi bright blazars
• A theoretical unifying scheme for gamma-ray bright blazars
• TeV Gamma Rays from BL Lac Objects due to Synchrotron Radiation of Extremely High Energy Protons
• Log-parabolic spectra and particle acceleration in the BL Lac object Mkn 421: spectral analysis of the complete BeppoSAX wide band X-ray data set
• A simplified view of blazars: clearing the fog around long-standing selection effects
• The Fermi blazar sequence
• 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
• Multiwavelength Evidence for Quasi-periodic Modulation in the Gamma-ray Blazar PG 1553+113
• Stochastic Acceleration and the Evolution of Spectral Distributions in SSC Sources: A Self Consistent Modeling of Blazars' Flares
• Optical and radio behaviour of the BL Lacertae object 0716+714
• X-ray spectral evolution of TeV BL Lac objects: eleven years of observations with BeppoSAX, XMM-Newton and SWIFT satellites
• Six years of BeppoSAX observations of blazars: a spectral catalog
• Black Hole Masses and Host Galaxy Evolution of Radio-loud Active Galactic Nuclei
• Signatures of synchrotron emission and of electron acceleration in the X-ray spectra of Mrk 421
• The Blazar PG 1553+113 as a Binary System of Supermassive Black Holes
• Blazar sequence - an artefact of Doppler boosting
• X-ray Flaring Activity of Mrk 421
• SWIFT observations of TeV BL Lac objects
• The curvature of spectral energy distribution of blazars
• Synoptic studies of seventeen blazars detected in very high-energy gamma-rays
• Jet precession driven by a supermassive black hole binary system in the BL Lac object PG 1553+113
• Hard X-ray properties of NuSTAR blazars
• The Long Term Optical Variability of the BL Lac object S5 0716+714: Evidence for a Precessing Jet
• Evolution of the Synchrotron Spectrum in Mrk421 during the 1998 Campaign
• Implications on the blazar sequence and inverse Compton models from Fermi bright blazars
• Intrinsic Correlations for Flaring Blazars Detected by Fermi
• X-ray Flares from Markarian 501
• Spectral Survey of X-Ray Bright Active Galactic Nuclei from the Rossi X-ray Timing Explorer
• The debeamed luminosity, sychrotron peak frequency and black hole mass of BL Lac objects
• Basic properties of Fermi blazars and the "blazar sequence"
• X-ray spectral studies of TeV gamma-ray emitting blazars
• X-ray Flux and Spectral Variability of Six TeV Blazars with \textit{NuSTAR}
• On the spectral curvature of VHE blazar 1ES\,1011+496: Effect of spatial particle diffusion
• Multiwavelength Observations of 1ES 1959+650, One Year After the Strong Outburst of 2002
• Evolution of the synchrotron and inverse Compton emissions of the low energy peaked BL Lac object S5 0716+714
• Curvature of the spectral energy distribution, the dominant process for inverse Compton component and other jet properties in Fermi 2LAC blazars
• Systematic investigation of X-ray spectral variability of TeV blazars during flares in the $RXTE$ era
• Swift XRT and UVOT deep observations of the high energy peaked BL Lac object PKS 0548-322 close to its brightest state
• Extremely rapid x-ray flares of tev blazars in the rxte era
• Influence of Energy-Dependent Particle Diffusion on the X-ray spectral curvature of MKN 421
• X-ray Spectral Variability of TeV Blazars during Rapid Flares

Cited by in corpus (8)

• The physical properties of $Fermi$-4LAC flat spectrum radio quasars
• High-energy neutrinos from X-rays flares of blazars frequently observed by the Swift X-Ray Telescope
• X-ray timing and spectral variability properties of blazars S5 0716+714, OJ 287, Mrk 501, and RBS 2070
• AstroSat observation of the HBL 1ES 1959+650 during its October 2017 flaring
• X-ray Studies of Blazar 1ES 1959+650 Using SWIFT & XMM-NEWTON Satellite
• X-Ray Spectral Variability of Thirteen TeV High Energy Peaked Blazars with XMM-Newton
• X-Ray Spectral Variability of the TeV HBL Blazar PG 1553+113 with XMM-Newton
• $L_{\mathrm{syn}}-E_{\mathrm{syn},\mathrm{p}}-\delta$ relation in Active Galactic Nucleus Jets and Implication for the physical origin of the $L_{\mathrm{p}}-E_{\mathrm{p},\mathrm{z}}-{\Gamma }_0$ relation of Gamma-Ray Bursts