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

Precise spectra of 3C 279 in the 0.5-70 keV range, obtained during two epochsof  \emph{Swift} and \emph{NuSTAR} observations, are analyzed using anear-equipartition model. We apply a one-zone leptonic model with athree-parameter log-parabola electron energy distribution (EED) to fit the\emph{Swift} and \emph{NuSTAR} X-ray data, as well as simultaneous optical and\emph{Fermi}-LAT $\gamma$-ray data. The Markov Chain Monte Carlo (MCMC)technique is used to search the high-dimensional parameter space and evaluatethe uncertainties on model parameters. We show that the two spectra can besuccessfully fit in near-equipartition conditions, defined by the ratio of theenergy density of relativistic electrons to magnetic field $\zeta_{\rm e}$being close to unity. In both spectra, the observed X-rays are dominated bysynchrotron-self Compton photons, and the observed $\gamma$ rays are dominatedby Compton scattering of external infrared photons from a surrounding dustytorus.  Model parameters are well constrained. From the low state to the high state,both the curvature of the log-parabola width parameter and the synchrotron peakfrequency significantly increase. The derived magnetic fields in the two statesare nearly identical ($\sim1$\ G), but the Doppler factor in the high state islarger than that in the low state ($\sim$28 versus $\sim$18). We derive thatthe gamma-ray emission site takes place outside the broad-line region, at$\gtrsim$ 0.1 pc from the black hole, but within the dusty torus. Implicationsfor 3C 279 as a source of high-energy cosmic-rays are discussed.

Parameter constraints in a near-equipartition model with multi-frequency \emph{NuSTAR}, \emph{Swift} and \emph{Fermi-LAT} data from 3C 279