A Method for Locating High Energy Dissipation Region in Blazar

Abstract

The production site of gamma-rays in blazar jet is an unresolved problem. We present a method to locate gamma-ray emission region in the framework of one-zone emission model. From measurements of core-shift effect, the relation between the magnetic field strengths ($B^{\prime }$) in the radio cores of jet and the distances ($R$) of these radio cores from central supermassive black hole (SMBH) can be inferred. Therefore once the magnetic field strength in gamma-ray emission region ($B_{\mathrm{diss}}^{\prime }$) is obtained, one can use the relation of $B^{\prime }$-$R$ to derive the distance ($R_{\mathrm{diss}}$) of gamma-ray emission region from SMBH. Here we evaluate the lower limit of $B_{\mathrm{diss}}^{\prime }$ by using the criteria that the optical variability timescale $t_{\mathrm{var}}$ should be longer or equal to the synchrotron radiation cooling timescale of the electrons that emit optical photons. We test the method with the observations of PSK 1510-089 and BL Lacertae, and derive $R_{\mathrm{diss}}<0.15{\delta }_{\mathrm{D}}^{1/3}(1+A{)}^{2/3}$pc for PSK 1510-089 with $t_{\mathrm{var}}\sim$ a few hours, and $R_{\mathrm{diss}}<0.003{\delta }_{\mathrm{D}}^{1/3}(1+A{)}^{2/3}$pc for BL Lacertae with $t_{\mathrm{var}}\sim$ a few minutes. Here ${\delta }_{\mathrm{D}}$ is the Doppler factor and $A$ is the Compton dominance (i.e., the ratio of the Compton to the synchrotron peak luminosities).

5 pages, 0 figures, accepted by ApJ

References in corpus (18)

• The power of relativistic jets is larger than the luminosity of their accretion disks
• Synchrotron Self-Compton Analysis of TeV X-ray Selected BL Lacertae Objects
• A hadronic origin for ultra-high-frequency-peaked BL Lac objects
• Gamma-Ray Studies of Blazars: Synchro-Compton Analysis of Flat Spectrum Radio Quasars
• Constraining the Location of Gamma-Ray Flares in Luminous Blazars
• Hadronic models of blazars require a change of the accretion paradigm
• Multi-wavelength observations of 3C 279 during the extremely bright gamma-ray flare in 2014 March-April
• Constraints on minimum electron Lorentz factor and matter content of jets for a sample of bright Fermi blazars
• Gamma-Gamma Absorption in the Broad Line Region Radiation Fields of Gamma-Ray Blazars
• Time Dependent Hadronic Modeling of Flat Spectrum Radio Quasars
• A self-consistent and time-dependent hybrid blazar emission model - Properties and application
• "Orphan" $\gamma$-ray Flares and Stationary Sheaths of Blazar Jets
• Understanding the TeV emission from a distant blazar PKS 1424+240 in a lepto-hadronic jet model
• Multiwavelength variability study and search for periodicity of PKS 1510-089
• Short Timescale Photometric and Polarimetric Behavior of two BL Lacertae Type Objects
• The sequence of Compton dominance in blazars based on data from WISE and Fermi/LAT
• Testing one-zone synchrotron-self-Compton models with spectral energy distributions of Mrk 421
• Constraints on the location of $\gamma$-ray emitting region for a sample of blazars with radio core-shift measurements

Cited by in corpus (11)

• A two-zone model for blazar emission: implications for TXS 0506+056 and the neutrino event IceCube-170922A
• The physical properties of $Fermi$-4LAC flat spectrum radio quasars
• The Estimation of Fundamental Physics Parameters for Fermi-LAT Blazars
• Multicolor Optical Monitoring of the Blazar S5 0716+714 from 2017 to 2019
• Statistical analysis on XMM-Newton X-ray flares of Mrk 421: distributions of peak flux and flaring time duration
• Multi-frequency study of the gamma-ray flaring BL Lac object PKS 2233-148 in 2009-2012
• Exploring the origin of multiwavelength activities of high-redshift FSRQ PKS 1502+106 during 2014-2018
• CTA 102 in exceptionally high state during 2016-17
• Locations of optical and $\gamma$-ray emitting regions in the jet of PMN J2345-1555
• Constraining Evolution of Magnetic Field Strength in Dissipation Region of Two BL Lac Objects
• Constraining the $\gamma$-ray Emission Region for Fermi-Detected FSRQs by the Seed Photon Approach