English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We model simultaneous or quasi-simultaneous multi-band spectral energydistributions (SEDs) for a sample of 25 blazars that have radio core-shiftmeasurements, where a one-zone leptonic model and Markov chain Monte Carlotechnique are adopted. In the SED fitting for 23 low-synchrotron-peaked (LSP)blazars, the seed photons from broad line region (BLR) and molecular torus areconsidered respectively in the external Compton process. We find that the SEDfitting with the seed photons from the torus are better than those utilizingBLR photons, which suggests that the $\gamma$-ray emitting region may belocated outside the BLR. Assuming the magnetic field strength in the$\gamma$-ray emitting region as constrained from the SED fitting follows themagnetic field distribution as derived from the radio core-shift measurements(i.e., $B(R)\simeq B_{\rm 1 pc}(R/\rm 1pc)^{-1}$, $R$ is the distance from thecentral engine and $B_{\rm 1 pc}$ is the magnetic field strength at 1 pc), wefurther calculate the location of the $\gamma$-ray emitting region,$R_{\gamma}$, for these blazars. We find that$R_{\gamma}\sim2\times10^{4}R_{\rm S}\simeq10 R_{\rm BLR}$ ($R_{\rm S}$ is theSchwarzschild radius and $R_{\rm BLR}$ is the BLR size), where $R_{\rm BLR}$ isestimated from the broad line luminosities using the empirical correlationsobtained using the reverberation mapping methods.

Constraints on the location of $\gamma$-ray emitting region for a sample of blazars with radio core-shift measurements