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Thermal radiation of supernova remnants in radio domen

dc.contributor.advisorUrošević, Dejan
dc.contributor.otherLeahy, D. A.
dc.contributor.otherArbutina, Bojan
dc.contributor.otherVukotić, Branislav
dc.creatorOnić, Dušan Ž
dc.date.accessioned2016-01-05T12:39:37Z
dc.date.available2016-01-05T12:39:37Z
dc.date.available2020-07-03T08:38:55Z
dc.date.issued2013-07-08
dc.identifier.urihttp://nardus.mpn.gov.rs/handle/123456789/2845
dc.identifier.urihttp://eteze.bg.ac.rs/application/showtheses?thesesId=1177
dc.identifier.urihttps://fedorabg.bg.ac.rs/fedora/get/o:8047/bdef:Content/download
dc.identifier.urihttp://vbs.rs/scripts/cobiss?command=DISPLAY&base=70036&RID=44727311
dc.description.abstractEvolucija ostataka supernovih vezana je za kretanje jednog, bezsudarnog udarnog talasa, nastalog prilikom prostiranja odbacenog zvezdanog materijala nakon eksplozije supernove, velikom brzinom kroz med-uzvezdanu sredinu. Teorijska razmatranja udarnih talasa su neophodna radi boljeg razumevanja emisionih maglina i, generalno, procesa u med-uzvezdanoj sredini. U okviru ove disertacije, izmed-u ostalog, predstavljeni su rezultati magnetohidrodinamicke (MHD) teorije udarnih talasa sa posebnim osvrtom na moguca resenja u svetlu modela idealne radijativne MHD za opticki gust slucaj. Specijalno, diskutovana su moguca svojstva udarnih talasa kada je dozvoljen skok adijabatskog indeksa i/ili parametra koji odred-uje odnos gasnog prema ukupnom pritisku. Osnovna hipoteza, razmatrana u okviru ove disertacije, odnosi se na mogucnost znacajnog ucesca termalnog zakocnog zracenja u neprekidnom radio-spektru pojedinih Galaktickih ostataka supernovih. Pozitivan odgovor na ovo pitanje bi mogao predstavljati prirodno objasnjenje blago konveksnih neprekidnih radio-spektara pojedinih Galaktickih ostataka koji se prostiru kroz sredinu koja je nesto gusca od prosecne. U tom smislu je vazno utvrditi postojanje indikatora termalnog ansambla elektrona, na dovoljno niskim temperaturama i dovoljno velikim gustinama, kako bi se zakocno zracenje moglo detektovati u radio-podrucju (blizina, interakcija ili prostiranje ostatka kroz molekulski oblak, prisustvo ohlad-enih elektrona koji su ranije zracili u X-podrucju, u fazama nakon Sedov-Tejlorove, detekcija niskofrekventnog krivljenja radio-spektra usled termalne apsorpcije vezane za sam ostatak, detekcija u H, identikacija radio-rekombinacionih linija vezanih za sam ostatak, itd). Znacajno prisustvo termalne komponente u principu moze objasniti i radiospektralne indekse manje od 0.5 odred-ene kod nekolicine evolutivno starijih ostataka (uglavnom mesane morfologije), koji se sire kroz guscu sredinu. Zapravo, u tom slucaju bi manji spektralni indeksi, pod pretpostavkom prostog stepenog zakona, predstavljali prirodnu manifestaciju znacajnog udela termalnog zakocnog zracenja u neprekidnom radio-spektru ostataka supernovih...sr
dc.description.abstractThe evolution of supernova remnants is linked to the propagation of a collisionless shock wave, formed during the initial expansion of high-velocity supernova ejecta through the interstellar environment. Theoretical studies of shock waves are very important for the analysis of supernova remnants, as well as processes in the interstellar medium in general. In this doctoral dissertation, some theoretical results based on the magnetohydrodynamical theory of shock waves are presented, with special emphasis on ideal radiative magnetohydrodynamics for the optically thick case. Particularly, solutions for the case when jump in adiabatic index and/or ratio of gas to total pressure is allowed, are discussed. The main hypothesis of this dissertation is that thermal bremsstrahlung radiation at radio continuum frequencies can provide a signicant contribution in the case of several Galactic supernova remnants. This hypothesis can give a natural explanation for nearly concave up radio continuum spectra of several Galactic supernova remnants that are expanding in the environment with higher than average density. In this context, it is important to identify the existence of the possible indicators of ensemble of thermal electrons at suciently low temperatures and suciently high densities so that the thermal bremsstrahlung radiation linked to a particular remnant could be observed at radio continuum frequencies (vicinity, interaction or expansion through the molecular cloud, presence of the cooled thermal X-ray electrons during the post Sedov-Taylor phases, detection of low-frequency turnovers associated with thermal absorption linked to the remnant, detection in H, identication of radio recombination lines linked to the remnant, etc)...en
dc.formatapplication/pdf
dc.languagesr
dc.publisherУниверзитет у Београду, Математички факултетsr
dc.relationinfo:eu-repo/grantAgreement/MESTD/Basic Research (BR or ON)/176005/RS//
dc.rightsopenAccessen
dc.sourceУниверзитет у Београдуsr
dc.subjectostaci supernovihsr
dc.subjectsupernova remnantsen
dc.subjectmed-uzvezdana materijasr
dc.subjectudarni talasisr
dc.subjectmagnetohidrodinamikasr
dc.subjectinterstellar mediumen
dc.subjectshock wavesen
dc.subjectmagnetohydrodynamicsen
dc.titleTermalno zračenje ostataka supernovih u radio-područjusr
dc.titleThermal radiation of supernova remnants in radio domenen
dc.typedoctoralThesis
dc.rights.licenseBY
dcterms.abstractУрошевић, Дејан; Вукотић, Бранислав; Леахy, Д. A.; Aрбутина, Бојан; Онић, Душан Ж; Термално зрачење остатака супернових у радио-подручју; Термално зрачење остатака супернових у радио-подручју;
dc.identifier.fulltexthttp://nardus.mpn.gov.rs/bitstream/id/6631/Disertacija.pdf


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