Modelovanje radio-evolucije ostataka supernovih na osnovu hidrodinamičkih simulacija i nelinearnog difuznog ubrzavanja čestica

Abstract

Eksplozije supernovih (SN) obogacuju Univerzum razlicitim teskim elementima. Ovi elementi su gradivni blokovi sveta oko nas i nas samih. Ostaci supernovih (OSN) su izvanredni astronomski objekti koji su takode od velikog naucnog znacaja, jer pruzaju uvid u mehanizme eksplozija supernovih i predstavljaju vazne izvore galakti ckih kosmickih zraka. Radio-posmatranja su medu najstarijim sredstvima za proucavanje ovih objekata. Radio-sjaj i spektar, posebno mladih OSN, predstavljaju rezultat aktivnog ubrzavanja elektrona na udarnim talasima. U ovoj doktorskoj disertaciji, analizira se radio-evolucija OSN primenom trodimenzionalnih hidrodinami ckih simulacija i nelinearnog difuznog ubrzavanja cestica. Hidrodinamicke simulacije, razvijane i prilagodavane u ovoj disertaciji, omogucavaju nam eksplicitno racunanje modikacije udarnih talasa od strane kosmickih zraka. Takode, ukljucujemo konzistentan numericki tretman pojacanja magnetnog polja usled rezonantnih i nerezonantnih nestabilnosti izazvanih kosmickim zracenjem. Modelovali smo radio-evoluciju najmladeg poznatog Galaktickog OSN G1.9+0.3 i zakljucili da je rastuca radio-emisija cesta pojava kod jako mladih OSN. Nas model nam je omogucio da izvedemo vazne zakljucke o sadasnjem i predvidanja o buducem ponasanju radio-emisije ovog OSN. Takode smo primenom simulacija razvili i opsti model radio-evolucije OSN, za sirok spektar relevantnih zickih parametara, kao sto su gustina okolne sredine, energija eksplozije supernove, ekasnost ubrzavanja i pojacanja magnetnog polja. Pouzdanost nasih radio-evolutivnih traka potvrdena je na posmatrackom uzorku, koji se sastoji od Galaktickih i vangalaktickih OSN...

Supernova (SN) explosions disperse the dierent heavy elements across the Universe. These elements are the building blocks which make up the world around and inside us. Supernova remnants (SNRs) are extraordinary astronomical objects that are also of high scientic interest, because they provide insights into aforementioned supernova explosion mechanisms, and because they are important sources of Galactic cosmic rays (CRs). Radio observations are among the oldest means to study these objects. The radio luminosity and spectra of SNRs, especially young ones, requires active acceleration of electrons by the SNR shocks. In this doctoral dissertation, radio evolution of SNRs is investigated by using three-dimensional hydrodynamic modelling and non-linear diusive shock acceleration of CRs in SNRs. Hydrodynamic simulations, developed and adopted in this dissertation, allow us to explicitly account for the shock modication by CRs. We also include consistent numerical treatment of magnetic eld amplication (MFA) due to CR resonant and non-resonant streaming instabilities. We modelled the peculiar nature of radio evolution of the youngest known Galactic SNR G1.9+0.3 and concluded that increasing radio emission is a common occurrence among very young SNRs. Our model enabled us to make important conclusions about the present and predictions about the future properties of radio emission from this SNR. We also developed more general model of the radio evolution of SNRs, by performing simulations for wide range of the relevant physical parameters, such as the ambient density, the supernova explosion energy, the acceleration eciency and the MFA eciency...