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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We study the dynamic changes of electron energy distribution (EED) throughsystematically analysing the quasi-simultaneous spectral energy distributions(SEDs) of the flat spectrum radio quasar 3C 279 in different states. WithMarkov chain Monte Carlo (MCMC) technique we model fourteen SEDs of 3C 279using a leptonic model with a three-parameter log-parabola electron energydistribution (EED). The 14 SEDs can be satisfactorily fitted with the one-zoneleptonic model. The observed $\gamma$ rays in 13 states are attributed toCompton scattering of external infrared photons from a surrounding dusty torus.The curved $\gamma$-ray spectrum observed during 2-8 April 2014 is wellexplained by the external Compton of dust radiation. It is found that there isa clear positive correlation between the curvature parameter $b$ of the EED andthe electron peak energy $\gamma'_{\rm pk}$. No clear correlation between $b$and the synchrotron peak frequency $\nu_{\rm s}$ is found, due to the variedproduct of Doppler factor and fluid magnetic field from state to state. Weinterpret the correlation of $b-\gamma'_{\rm pk}$ in a stochastic accelerationscenario. This positive correlation is in agreement with the prediction in thestage when the balance between acceleration and radiative cooling of theelectrons is nearly established in the case of the turbulence spectral index$q=2$.

Dynamic changes of emitting electron distribution in the jet of 3C 279: signatures of acceleration and cooling