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 Tools annual

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 monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Turbulence is a predominant process for energizing electrons and ions incollisionless astrophysical plasmas, and thus is responsible for shaping theirradiative signatures (luminosity, spectra, and variability). To betterunderstand the kinetic properties of a collisionless radiative plasma subjectto externally driven turbulence, we investigate particle-in-cell simulations ofrelativistic plasma turbulence with external inverse Compton cooling acting onthe electrons. We find that ions continuously heat up while electrons graduallycool down (due to the net effect of radiation), and hence the ion-to-electrontemperature ratio $T_i/T_e$ grows in time. We show that $T_i/T_e$ is limitedonly by the size and duration of the simulations (reaching $T_i/T_e \sim10^3$), indicating that there are no efficient collisionless mechanisms ofelectron-ion thermal coupling. This result has implications for models ofradiatively inefficient accretion flows, such as observed in the GalacticCenter and in M87, for which so-called two-temperature plasmas with $T_i/T_e\gg 1$ have been invoked to explain their low luminosity. Additionally, we findthat electrons acquire a quasi-thermal distribution (dictated by thecompetition of turbulent particle energization and radiative cooling), whileions undergo efficient nonthermal acceleration (acquiring a harder distributionthan in equivalent non-radiative simulations). There is a modest nonthermalpopulation of high-energy electrons that are beamed intermittently in space,time, and direction; these beamed electrons may explain rapid flares in certainhigh-energy astrophysical systems (e.g., in the Galactic Center). Thesenumerical results demonstrate that extreme two-temperature plasmas can beproduced and maintained by relativistic radiative turbulence.

Production and persistence of extreme two-temperature plasmas in radiative relativistic turbulence