Modelovanje radio-evolucije ostataka supernovih na osnovu hidrodinamičkih simulacija i nelinearnog difuznog ubrzavanja čestica
Modeling the radio-evolution of supernova remnants by using hydrodynamic simulations and non-linear diffusive shock acceleration
Doktorand
Pavlović, MarkoMentor
Urošević, DejanČlanovi komisije
Arbutina, BojanVukotić, Branislav
Onić, Dušan
Metapodaci
Prikaz svih podataka o disertacijiSažetak
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 izazva...nih 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 am...plication (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...
Fakultet:
Универзитет у Београду, Математички факултетDatum odbrane:
26-04-2018Projekti:
- Emisione magline: struktura i evolucija (RS-176005)