On the maximum energy of protons in the hotspots of AGN jets

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F19%3A00535014" target="_blank" >RIV/67985815:_____/19:00535014 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1051/epjconf/201921004006" target="_blank" >https://doi.org/10.1051/epjconf/201921004006</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/epjconf/201921004006" target="_blank" >10.1051/epjconf/201921004006</a>

Jazyk výsledku

angličtina

Název v původním jazyce

On the maximum energy of protons in the hotspots of AGN jets

Popis výsledku v původním jazyce

We study particle acceleration and magnetic field amplification in the termination shocks (hotspots) of radiogalaxy jets. The cut-off of the synchrotron spectrum in the hotspots of powerful radiogalaxies is typically observed between infrared and optical frequencies, indicating that the maximum energy of non-thermal electrons accelerated at the jet termination shock is about 1 TeV for a canonical magnetic field of 100 mu G. Based on theoretical considerations and observational data we show that the maximum energy of electrons cannot be constrained by synchrotron losses as usually assumed, unless the jet density is unreasonable large and most of the jet kinetic energy goes to non-thermal electrons. The maximum energy is ultimately determined by the ability to scatter particles back and forth the shock, and this limit applies to both electrons and protons. Therefore, the maximum energy of protons is also about 1 TeV when radiative cooling is not efficient. We show that non-resonant hybrid (Bell) instabilities generated by the streaming of cosmic rays can grow fast enough to amplify the jet magnetic field up to 100 mu G and accelerate particles up to the maximum energies observed in the hotspots of radiogalaxies.

Název v anglickém jazyce

On the maximum energy of protons in the hotspots of AGN jets

Popis výsledku anglicky

We study particle acceleration and magnetic field amplification in the termination shocks (hotspots) of radiogalaxy jets. The cut-off of the synchrotron spectrum in the hotspots of powerful radiogalaxies is typically observed between infrared and optical frequencies, indicating that the maximum energy of non-thermal electrons accelerated at the jet termination shock is about 1 TeV for a canonical magnetic field of 100 mu G. Based on theoretical considerations and observational data we show that the maximum energy of electrons cannot be constrained by synchrotron losses as usually assumed, unless the jet density is unreasonable large and most of the jet kinetic energy goes to non-thermal electrons. The maximum energy is ultimately determined by the ability to scatter particles back and forth the shock, and this limit applies to both electrons and protons. Therefore, the maximum energy of protons is also about 1 TeV when radiative cooling is not efficient. We show that non-resonant hybrid (Bell) instabilities generated by the streaming of cosmic rays can grow fast enough to amplify the jet magnetic field up to 100 mu G and accelerate particles up to the maximum energies observed in the hotspots of radiogalaxies.

Druh

D - Stať ve sborníku

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

<a href="/cs/project/GB14-37086G" target="_blank" >GB14-37086G: Centrum Alberta Einsteina pro gravitaci a astrofyziku</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2019

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název statě ve sborníku

EPJ Web of Conferences.

ISBN

—

ISSN

2100-014X

e-ISSN

—

Počet stran výsledku

6

Strana od-do

04006

Název nakladatele

EDP Sciences

Místo vydání

Les Ulis

Místo konání akce

Paris

Datum konání akce

8. 10. 2018

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

000570466200037