H2020Индивидуална стипендия2021–2023

EMAXSHOCK · On the maximum energy of particles accelerated in astrophysical jets

„Хоризонт 2020“ — Действия „Мария Склодовска-Кюри“

Период: 2021-03-01 → 2023-02-28
Финансиране от ЕС: 184 708 €
Участници: 1
Схема: MSCA-IF

Линиите свързват координатора с партньорите.

Накратко на български

Максималната енергия на частиците в струите на активни галактики и протозвезди се анализира чрез процеси на ускоряване в ударни вълни. Това помага да се разбере произходът на космическите лъчи и да се идентифицират нови източници на гама-лъчи в Космоса.

Този кратък обзор е генериран от изкуствен интелект

Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.

Резултати накратко

On the maximum energy of particles accelerated in astrophysical jets

The problem being addressed is the efficiency of particle acceleration and magnetic field amplification in mildly relativistic and low velocity shocks, in radiogalaxy and protostellar jets, respectively. In the former case I am focused on the study of magnetic field amplification in active galactic nuclei (AGN) jets and the maximum energy that particles can achieve. In the later case we aim to address if protostellar jets can accelerate TeV particles, and therefore be a potential new kind of gamma-ray sources for future gamma-ray facilities like the Cerenkov Telescope Array. Understanding the micro-physics of mildly relativistic and low velocity plasma has important implications for different fields in Astrophysics. In particular, one of the most exciting and unsolved problems is the origin of the Ultra High Energy Cosmic Rays. These particles have an energy of about 100 EeV and arrive on the Earth from outside the Galaxy, but their origin remains unknown. At lower energies (< 3 PeV) cosmic rays are likely galactic. With that respect, a large fraction of gamma-ray sources in the Galaxy remain unidentified, and jets from protostars are among candidates to be the hidden CR accelerators and gamma-ray emitters. The overall objective of this project is the investigation of the maximum energy that particles can achieve when they are accelerated via diffusive shock acceleration in both mildly-relativistic and low-velocity shocks, in AGN and protostellar jets, respectively. Particles are accelerated at shocks and the magnetic field is likely amplified by the cosmic-ray streaming instability due to the fast drift of the particles in the background plasma. We want to find the maximum energy that particles can achieve when they are accelerated in shocks with different velocities in plasma with different densities. We also investigate the micro-physics of particle acceleration in collision-less shocks generated by intense lasers.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз

Цел на проекта

Astrophysical jets moving in an external medium produce shocks where particles can be accelerated via Diffusive Shock Acceleration (DSA). The main uncertainty is the maximum energy that particles can achieve, and this has important implications for different fields in astrophysics. In particular, one of the most exciting problems is the origin of the Ultra High Energy Cosmic Rays, and jets from Active Galactic Nuclei (AGN) have been proposed as candidates. At lower energies cosmic rays are likely galactic. With that respect, a large fraction of gamma-raysources in the Galaxy remain unidentified, and protostellar jets are among candidates to be the hidden cosmic ray accelerators. It was very recently demonstrated that mildly relativistic shocks in the backflows in the lobes of AGN jets can accelerate particles up to the Hillas energy, offering a suitable environment for the acceleration of UHECRs. However, in order to account for the heavy composition of the UHECR spectrum, a jet mass loading mechanism is needed. At lower energies, acceleration of TeV particles in protostellar jets can be quenched by ion-neutral collisions, and therefore kinetic calculations are desirable in order to compute the maximum energy of particles in low velocity shocks and non-completely ionized plasmas. I will investigate the maximum energy that particles can achieve when they are accelerated via DSA in mildly-relativistic and low-velocity shocks, in AGN and protostellar jets, respectively. In the former case I will consider the shocks produced by the interaction of powerful stellar winds with the jets, whereas in the latter case we will consider the jet termination shocks. By performing unprecedented calculations with the a newly developed hybrid code, I aim to address the maximum energy and composition of the UHECR spectrum by modeling the backflows of jet/wind interactions. In addition, I aim to address if protostellar jets can accelerate TeV particles and emit gamma rays.

Оригинален текст от CORDIS (на английски).

Участници

CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS · ParisКоординаторФранция