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

The flat spectrum radio quasar 3C 279 is a known $\gamma$-ray variable sourcethat has recently exhibited minute-scale variability at energies $>100$ MeV.One-zone leptonic models for blazar emission are severely constrained by theshort timescale variability that implies a very compact emission region at adistance of hundreds of Schwarzschild radii from the central black hole. Here,we investigate a hadronic scenario where GeV $\gamma$-rays are produced viaproton synchrotron radiation. We also take into account the effects of thehadronically initiated electromagnetic cascades (EMC). For a $\gamma$-rayemitting region in rough equipartition between particles and kG magneticfields, located within the broad-line region (BLR), the development of EMCredistributes the $\gamma$-ray luminosity to softer energy bands and eventuallyleads to broad-band spectra that differ from the observed ones. Suppression ofEMC and energy equipartition are still possible, if the $\gamma$-ray emittingregion is located beyond the BLR, is fast moving with Doppler factor ($>70$),and contains strong magnetic fields ($>100$ G). Yet, these conditions cannot beeasily met in parsec-scale jets, thus disfavouring a proton synchrotron originof the Fermi-LAT flare.

A hadronic minute-scale GeV flare from quasar 3C 279?