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master's thesis
Polarizirano zračenje radio galaksija na niskim radio frekvencijama
Zagreb: University of Zagreb, Faculty of Science, 2018. urn:nbn:hr:217:992842
Barišić, Dario
University of Zagreb
Faculty of Science
Department of Physics

Institutional repository: Repository of the Faculty of Science

Cite this document

Barišić, D. (2018). Polarizirano zračenje radio galaksija na niskim radio frekvencijama (Master's thesis). Zagreb: University of Zagreb, Faculty of Science. Retrieved from https://urn.nsk.hr/urn:nbn:hr:217:992842

Barišić, Dario. "Polarizirano zračenje radio galaksija na niskim radio frekvencijama." Master's thesis, University of Zagreb, Faculty of Science, 2018. https://urn.nsk.hr/urn:nbn:hr:217:992842

Barišić, Dario. "Polarizirano zračenje radio galaksija na niskim radio frekvencijama." Master's thesis, University of Zagreb, Faculty of Science, 2018. https://urn.nsk.hr/urn:nbn:hr:217:992842

Barišić, D. (2018). 'Polarizirano zračenje radio galaksija na niskim radio frekvencijama', Master's thesis, University of Zagreb, Faculty of Science, accessed 25 July 2024, https://urn.nsk.hr/urn:nbn:hr:217:992842

Barišić D. Polarizirano zračenje radio galaksija na niskim radio frekvencijama [Master's thesis]. Zagreb: University of Zagreb, Faculty of Science; 2018 [cited 2024 July 25] Available at: https://urn.nsk.hr/urn:nbn:hr:217:992842

D. Barišić, "Polarizirano zračenje radio galaksija na niskim radio frekvencijama", Master's thesis, University of Zagreb, Faculty of Science, Zagreb, 2018. Available at: https://urn.nsk.hr/urn:nbn:hr:217:992842

Metadata
TitlePolarizirano zračenje radio galaksija na niskim radio frekvencijama
Title (english)Polarised emission of galaxies at low radio frequencies
AuthorDario Barišić
MentorVibor Jelić (mentor)
MentorKrešimir Pavlovski (mentor)
Committee memberKrešimir Pavlovski (predsjednik povjerenstva)
Committee memberVibor Jelić (član povjerenstva)
Committee memberIvica Smolić (član povjerenstva)
Committee memberVernesa Smolčić (član povjerenstva)
Committee memberMaro Cvitan (član povjerenstva)
GranterUniversity of Zagreb
Faculty of Science
(Department of Physics)
Zagreb
Defense date and country2018-11-19, Croatia
Scientific / art field,
discipline and subdiscipline		NATURAL SCIENCES
Physics
Abstract
U ovom radu bavimo se potragom za polariziranim zračenjem radiogalaksija koristeći polarimetrijska promatranja na 150 MHz prikupljena LOFAR teleskopom u području centriranom na sjajnoj radiogalaksiji 3C196 (RA = 8h13m36s, DEC = +48°13'03'') koje obuhvaća oko 50 kvadratnih stupnjeva. Ukupno smo pronašli 10 polariziranih radioizvora. Analizom slika iz FIRST kataloga na 1.4 GHz ustanovili smo da su 9 izvora radiogalaksije FR-II tipa koje su luminoznije prema rubovima, a preostali izvor je kvazar. Izračunati postotci polarizacije izvora na 150 MHz pokazuju znatno veću depolarizaciju u odnosu na mjerenja iz NVSS kataloga na frekvencijama oko 1.4 GHz. Za pojedine izvore postoje velike razlike između Faradayevih dubina dobivenih iz LOFAR-ovih mjerenja i onih koje se navode u NVSS katalogu, što pripisujemo niskoj rezoluciji u Faraday prostoru za NVSS-ova mjerenja. Usporedbom dobivenih vrijednosti ukupnog intenziteta s onima na drugim frekvencijama, koje smo pronašli u VLSS (74 MHz), NVSS (1.4 GHz) i WENSS (325 MHz) katalozima, dobili smo vrijednosti spektralnih indeksa koji u prosjeku iznose 0.753. Dobivena je gustoća od jednog izvora na 5 kvadratnih stupnjeva neba.
Abstract (english)
In this Diploma thesis we are searching for polarized emission of the radio galaxies in a field centred at a bight radio galaxy 3C196 (RA = 8h13m36s, DEC = +48°13'03''), covering an area of 50 square degrees. In our analysis we are using LOFAR polarimetric observations at 150 MHz. In total we have found 10 polarized radio sources. By analysing the FIRST images of these sources we concluded that one source is a quasar, while all the others are FR-II radio galaxies, which are the brightest at the edges. Their degree of polarization at 150 MHz is smaller than at 1.4 GHz (NVSS catalogue), due to significantly higher wavelenght dependent depolarization. There is some discrepancy in obtained rotation measures if compared with the ones at 1.4 GHz. This can be attributed to much poorer resolution in Faraday depth at higher radio frequencies. We also compared the amount of emission obtained in total intensity with catalogues at other frequencies (VLSS - 74 MHz, WENSS - 325 MHz, NVSS - 1.4 GH). Based on this comparison we calculated the spectral indices of the sources, mounting to 0.753 in average. We found a density of 1 source per 5 square degrees.
Keywords
Keywords (english)
Languagecroatian
URN:NBNurn:nbn:hr:217:992842
Study programmeTitle: Physics; specializations in: Research
Course: Research
Study programme type: university
Study level: integrated undergraduate and graduate
Academic / professional title: magistar/magistra fizike (magistar/magistra fizike)
Type of resourceText
File originBorn digital
Access conditionsOpen access
Terms of useLicence In copyright icon
Created on2018-11-20 13:12:09