A search for pulsed high-energy non-thermal emission from the nova-like variable system AE Aquarii
| dc.contributor.advisor | Meintjes, P. J. | |
| dc.contributor.author | Van Heerden, Hendrik Jacobus | |
| dc.date.accessioned | 2016-01-11T10:41:17Z | |
| dc.date.available | 2016-01-11T10:41:17Z | |
| dc.date.issued | 2015-05 | |
| dc.description.abstract | English: AE Aquarii is an peculiar nova like variable system with emission observable in almost all wavelength regimes. The emission consists of both thermal and nonthermal components. The parameters and models for the non-thermal Synchrotron emission in the radio regime, as well as the optical and UV emission, have been extensively studied and presented since this enigmatic source was first studied in the 1930s. However, the emission processes and parameters towards the higher energies are still not clearly verified. The possibility of non-thermal pulsed emission in the VHE energies was mentioned in previous studies, as well as possible correlations between this pulsed emission and periods of enhanced optical activity. We searched for non-thermal high energy emission from AE Aquarii using archival data from Suzaku, Fermi and AGILE along with contemporaneous optical photometric data from Boyden Observatory and SAAO. Analysis of the parameters of optical ares resulted in signatures that was used to identify possible correlating features in the Fermi-LAT data. In addition, we found that given the presence of a thermal component in conjunction with a power-law towards higher energies in the Suzaku X-ray data, as well as a possible low-level pulse signal in the Fermi- LAT data at the first harmonic of the white dwarf spin period, the possibility of non-thermal high energy emission from AE Aquarii cannot be excluded. The possible low-level signal in the Fermi-LAT data was as a result of a novel peak distribution analysis technique. Finally, an updated spectral energy distribution for AE Aquarii was completed to serve as a reference for future studies. | en_ZA |
| dc.description.abstract | Afrikaans: AE Aquarii is 'n eienaardige nova-agtige veranderlike stelsel met emissie wat in amper alle gol engtes waargeneem kan word. Hierdie emissie bestaan uit beide termiese en nie-termiese komponente. Uitgebreide studies rakende die parameters en modelle vir die nie-termiese Synchrotron emissie in die radio-gebied, sowel as die optiese en UV-emissie is al voorheen gebestudeer en aangebied sedert hierdie raaiselagtige stelsel die eerste keer bestudeer is in die 1930s. Die emisse-prosesse en -parameters by hoer energie is daarteenoor nog nie baie goed bevestig nie. Vorige studies het die moontlikheid van nie-termiese gepulseerde emissie in die baie hoe energie-gebied getoon, met moontlike korrelasies ten tye van verhoogde optiese aktiwiteit. Ons het gebruik gemaak van argief-data verkry vanaf Suzaku, Fermi en AG- ILE tesame met gelyktydige optiese fotometriese data vanaf Boyden Sterrewag en SAAO om vir nie-termiese hoe-energie-emissie vanaf AE Aquarii te soek. Ontleding van die parameters van optiese uitbarstings het gelei tot aanduidings wat gebruik is om moontlike korrelasie kenmerke in die Fermi-LAT data te identiseer. Bykomend het ons bevind dat 'n termiese komponent tesame met 'n magswet na hoer energiee in die X-straal-data, sowel as die moontlikheid van 'n lae-vlak periodiese sein in die Fermi-LAT data by die eerste harmoniek van die wit-dwerg spin-periode teenwoordig kan wees. Daarom kan die moontlikheid van nie-termiese hoe energie emissie vanaf AE Aquarii nie uitgeskakel word nie. Die moontlike laevlak sein in die Fermi-LAT data was as gevolg van 'n nuwe piek verspreiding analise tegniek. Ten slotte, is 'n opgedateerde spektrale energie verspreiding vir AE Aquarii voltooi, om te dien as 'n verwysing vir toekomstige studies. | |
| dc.identifier.uri | http://hdl.handle.net/11660/2124 | |
| dc.language.iso | en | en_ZA |
| dc.publisher | University of the Free State | en_ZA |
| dc.rights.holder | University of the Free State | en_ZA |
| dc.subject | VHE emission | en_ZA |
| dc.subject | Non-thermal emission | en_ZA |
| dc.subject | Fermi space telescope | en_ZA |
| dc.subject | AG- ILE space telescope | en_ZA |
| dc.subject | Suzaku space telescope | en_ZA |
| dc.subject | Multi-wavelength analysis | en_ZA |
| dc.subject | Photometry | en_ZA |
| dc.subject | X-ray spectral analysis | en_ZA |
| dc.subject | Cataclysmic variable star | en_ZA |
| dc.subject | Star - AE Aquarii | en_ZA |
| dc.subject | Time series analysis | en_ZA |
| dc.subject | Thesis (Ph.D. (Physics))--University of the Free State, 2015 | en_ZA |
| dc.title | A search for pulsed high-energy non-thermal emission from the nova-like variable system AE Aquarii | en_ZA |
| dc.type | Thesis | en_ZA |