The variability properties of active galactic nuclei and their intractions with the host galaxies
| Autor(a) principal: | |
|---|---|
| Data de Publicação: | 2021 |
| Tipo de documento: | Tese |
| Idioma: | por |
| Título da fonte: | Repositório Institucional da UFRN |
| Texto Completo: | https://repositorio.ufrn.br/handle/123456789/31964 |
Resumo: | Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES |
| id |
UFRN_3c56bded55e56755f9f58df0674ec1b4 |
|---|---|
| oai_identifier_str |
oai:https://repositorio.ufrn.br:123456789/31964 |
| network_acronym_str |
UFRN |
| network_name_str |
Repositório Institucional da UFRN |
| repository_id_str |
|
| spelling |
Belete, Asnakew Bewketuhttp://lattes.cnpq.br/1914709220232970http://lattes.cnpq.br/9151590034650501Martins, Bruno Leonardo Cantohttp://lattes.cnpq.br/2673267660389058Leão, Izan de Castrohttp://lattes.cnpq.br/2153938352979031Alcaniz, Jailson Souza dehttp://lattes.cnpq.br/4351190607357917Abraham, Zulemahttp://lattes.cnpq.br/8085880003164254Medeiros, José Renan de2021-03-22T18:40:39Z2021-03-22T18:40:39Z2021-01-29BELETE, Asnakew Bewketu. The variability properties of active galactic nuclei and their intractions with the host galaxies. 2021. 193f. Tese (Doutorado em Física) - Centro de Ciências Exatas e da Terra, Universidade Federal do Rio Grande do Norte, Natal, 2021.https://repositorio.ufrn.br/handle/123456789/31964Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPESConselho Nacional de Desenvolvimento Científico e Tecnológico - CNPqActive galactic nuclei (AGNs), a compact regions that consist of a super-massive black hole surrounded by an accretion disk in the center of massive galaxies, have long been known in their unique observational properties. Strong variability has been identified as one of those properties that can be used to probe the interior of the system. Also, most astrophysical objects, like AGNs, are possibly associated with continuous nonlinear stochastic systems due to their complexity in nature. It has been indicated that quasars, a sub-class of AGN, are among complex systems that have nonlinear time series characterized by fractal behavior and also by sudden bursts of very large amplitude, implying that the dynamical evolution of quasars is nonlinear (i.e., described by nonlinear stochastic differential equations). Additionally, there is a suggestion that extragalactic radio sources are intermittent on timescales of ∼ 104 - 105 yr. Despite the complex nature of AGNs, astronomers have been trying to investigate the variability properties of AGNs using linear techniques, such as structure function, periodogram, Fourier analysis, etc. However, most valuable information in a complex system signal is contained by its irregular structures and transient phenomena called singularities. Thus, particularly in physics, it is important to analyze irregular structures in a signal to deduce properties about the underlying physical phenomena. Moreover, among other evidences, the recently discovered tight correlation between super-massive black hole mass and the host galaxy bulge properties revealed the fact that AGNs are not isolated objects -they interact and co-evolve with their host galaxies. The interaction mechanisms are thought to be through AGN feedback and feeding, and have been known to affect both the observational properties of AGNs, and the properties and kinematics of the gas in the surrounding environment, thereby regulating AGN- host galaxy co-evolution. Thus, understanding the types of variabilities along with their driving physical mechanisms and the physics behind the AGN-host galaxy interaction mechanisms (AGN feedback and feeding) provides a potentially significant information to constrain the nature of AGNs and get a full picture to construct a universal model to study the co-evolution of the two physically connected systems. The AGN-host galaxy interaction can easily be studied by modelling the kinematics of gas (in all form) in the nuclear/circumnuclear regions of the host galaxy. In this thesis I studied the nonlinear (multifractal) signature printed in the long-term light curves of different classes of AGNs and its correlation with different AGN and other observational parameters, and whether multifractality is an intrinsic behaviour of AGNs and it can be affected by extrinsic variations (e.g., gravitational lensing). I applied the onedimensional multifractal detrended moving average and the wavelet transform modulus maxima approachs to characterize the nonlinearity presented in the light curves. In addition, I also present the analysis of the kinematics of CO molecular gas in the nuclear and circumnuclear regions of three nearby Seyfert galaxies, NGC 4968, NGC 4845, and MCG-06- 30-15, by using their bright CO(2-1) emission line as a tracer. I used two different softwares, namely the 3D-Based Analysis of Rotating Object via Line Observations (3DBAROLO) and DiskFit, to model the kinematics of cold CO molecular gas in these three galaxies. I found that AGNs are complex, strongly nonlinear and intermittent systems, the degree of nonlinearity does not change with cosmological redshift, indicating that AGNs are intrinsically nonlinear systems, and the information contained in their light curves cannot be fully captured by linear analysis techniques. However, the nonlinear behaviour of AGNs is found to be affected by extrinsic variation (gravitational lensing). Moreover, the degree of nonlinearity is found to be inversely correlated with wavelength, the shorter the wavelength the stronger the nonlinearity, and strongly correlated with fractional variability amplitude. I did not find any significant correlation between the degree of nonlinearity of the Hβ line and AGN parameters such as black hole mass, the size of the Broad-Line Region (BLR) and continuum luminosity. Similarly, no important correlation found between the degree of nonlinearity of the continuum at 5100 Å and parameters such as black hole mass and the continuum luminosity, however a slight correlation is observed between the degree of nonlinearity of the AGN continuum at 5100 Å and the Eddington ratio (Lcont/MBH). I also found that reprocessing in the BLR introduces additional nonlinearity, i.e. the reprocessing in the BLR increases the nonlinearity of the ionizing continuum. Circular motion is found to be the dominant kinematics of the CO molecular gas in the inner molecular disk of the three nearby Seyfert galaxies, NGC 4968, NGC 4845 and MCG06-30-15, mainly in NGC 4845 and MCG-06-30-15. However, there is a clear evidence for the presence of non-circular motions in the central regions of NGC 4968 and NGC 4845. The strongest non-circular motion is detected in the nuclear region of NGC 4968, mainly in the minor kinematic axis, with velocity ∼ 125 km s −1 . For NGC 4968, the Ωb pattern speed for the bar put corotation at 3.5 kpc and inner Lindblad resonance (ILR) ring at R = 300pc, which corresponds to the CO ring. Moreover, of all DiskFit models, bisymmetric model is found to be the best-fit model, indicating that the observed non-circular motions, mainly in NGC 4968, could be due the molecular gas in the disk of the galaxy being perturbed by the nuclear barred structure. For the galaxy NGC 4968, the computation of the torques exerted by the stellar bar on the gas are positive inside the molecular ring, and negative inside, revealing that the gas is accumulating in the inner Lindblad resonance. Since there is no any strong evidence for molecular outflows in all the three galaxies NGC 4968, NGC 4845, and MCG-06-15-30, I cannot claim any strong evidence in these sources of the long sought feedback/feeding effect due to the AGN presence. Considering the CO-to-H2 conversion factor α in the interval [0.8, 3.2], the molecular mass M(H2) in the nuclear disk is estimated to be ∼ 3 − 12 × 107 M (NGC 4968), ∼ 9 − 36 × 107 M (NGC 4845), and ∼ 1 − 4 × 107 M (MCG-06-30-15).Universidade Federal do Rio Grande do NortePROGRAMA DE PÓS-GRADUAÇÃO EM FÍSICAUFRNBrasilVariability propertiesActive galactic nucleiGalaxiesThe variability properties of active galactic nuclei and their intractions with the host galaxiesinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisinfo:eu-repo/semantics/openAccessporreponame:Repositório Institucional da UFRNinstname:Universidade Federal do Rio Grande do Norte (UFRN)instacron:UFRNTEXTVariabilitypropertiesactive_Belete_2021.pdf.txtVariabilitypropertiesactive_Belete_2021.pdf.txtExtracted texttext/plain472114https://repositorio.ufrn.br/bitstream/123456789/31964/2/Variabilitypropertiesactive_Belete_2021.pdf.txt95c279ca10f08aa16be1cac889fcb46eMD52THUMBNAILVariabilitypropertiesactive_Belete_2021.pdf.jpgVariabilitypropertiesactive_Belete_2021.pdf.jpgGenerated Thumbnailimage/jpeg1309https://repositorio.ufrn.br/bitstream/123456789/31964/3/Variabilitypropertiesactive_Belete_2021.pdf.jpg1d9d6a842d261a1a0083a0223fdaa36bMD53ORIGINALVariabilitypropertiesactive_Belete_2021.pdfapplication/pdf64705645https://repositorio.ufrn.br/bitstream/123456789/31964/1/Variabilitypropertiesactive_Belete_2021.pdf2e14ba05d4852b8d6ffe9ba1fab627daMD51123456789/319642021-03-28 05:53:54.948oai:https://repositorio.ufrn.br:123456789/31964Repositório de PublicaçõesPUBhttp://repositorio.ufrn.br/oai/opendoar:2021-03-28T08:53:54Repositório Institucional da UFRN - Universidade Federal do Rio Grande do Norte (UFRN)false |
| dc.title.pt_BR.fl_str_mv |
The variability properties of active galactic nuclei and their intractions with the host galaxies |
| title |
The variability properties of active galactic nuclei and their intractions with the host galaxies |
| spellingShingle |
The variability properties of active galactic nuclei and their intractions with the host galaxies Belete, Asnakew Bewketu Variability properties Active galactic nuclei Galaxies |
| title_short |
The variability properties of active galactic nuclei and their intractions with the host galaxies |
| title_full |
The variability properties of active galactic nuclei and their intractions with the host galaxies |
| title_fullStr |
The variability properties of active galactic nuclei and their intractions with the host galaxies |
| title_full_unstemmed |
The variability properties of active galactic nuclei and their intractions with the host galaxies |
| title_sort |
The variability properties of active galactic nuclei and their intractions with the host galaxies |
| author |
Belete, Asnakew Bewketu |
| author_facet |
Belete, Asnakew Bewketu |
| author_role |
author |
| dc.contributor.authorID.pt_BR.fl_str_mv |
|
| dc.contributor.authorLattes.pt_BR.fl_str_mv |
http://lattes.cnpq.br/1914709220232970 |
| dc.contributor.advisorID.pt_BR.fl_str_mv |
|
| dc.contributor.advisorLattes.pt_BR.fl_str_mv |
http://lattes.cnpq.br/9151590034650501 |
| dc.contributor.advisor-co1ID.pt_BR.fl_str_mv |
|
| dc.contributor.referees1.none.fl_str_mv |
Leão, Izan de Castro |
| dc.contributor.referees1ID.pt_BR.fl_str_mv |
|
| dc.contributor.referees1Lattes.pt_BR.fl_str_mv |
http://lattes.cnpq.br/2153938352979031 |
| dc.contributor.referees2.none.fl_str_mv |
Alcaniz, Jailson Souza de |
| dc.contributor.referees2ID.pt_BR.fl_str_mv |
|
| dc.contributor.referees2Lattes.pt_BR.fl_str_mv |
http://lattes.cnpq.br/4351190607357917 |
| dc.contributor.referees3.none.fl_str_mv |
Abraham, Zulema |
| dc.contributor.referees3ID.pt_BR.fl_str_mv |
|
| dc.contributor.referees3Lattes.pt_BR.fl_str_mv |
http://lattes.cnpq.br/8085880003164254 |
| dc.contributor.author.fl_str_mv |
Belete, Asnakew Bewketu |
| dc.contributor.advisor-co1.fl_str_mv |
Martins, Bruno Leonardo Canto |
| dc.contributor.advisor-co1Lattes.fl_str_mv |
http://lattes.cnpq.br/2673267660389058 |
| dc.contributor.advisor1.fl_str_mv |
Medeiros, José Renan de |
| contributor_str_mv |
Martins, Bruno Leonardo Canto Medeiros, José Renan de |
| dc.subject.por.fl_str_mv |
Variability properties Active galactic nuclei Galaxies |
| topic |
Variability properties Active galactic nuclei Galaxies |
| description |
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES |
| publishDate |
2021 |
| dc.date.accessioned.fl_str_mv |
2021-03-22T18:40:39Z |
| dc.date.available.fl_str_mv |
2021-03-22T18:40:39Z |
| dc.date.issued.fl_str_mv |
2021-01-29 |
| dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
| dc.type.driver.fl_str_mv |
info:eu-repo/semantics/doctoralThesis |
| format |
doctoralThesis |
| status_str |
publishedVersion |
| dc.identifier.citation.fl_str_mv |
BELETE, Asnakew Bewketu. The variability properties of active galactic nuclei and their intractions with the host galaxies. 2021. 193f. Tese (Doutorado em Física) - Centro de Ciências Exatas e da Terra, Universidade Federal do Rio Grande do Norte, Natal, 2021. |
| dc.identifier.uri.fl_str_mv |
https://repositorio.ufrn.br/handle/123456789/31964 |
| identifier_str_mv |
BELETE, Asnakew Bewketu. The variability properties of active galactic nuclei and their intractions with the host galaxies. 2021. 193f. Tese (Doutorado em Física) - Centro de Ciências Exatas e da Terra, Universidade Federal do Rio Grande do Norte, Natal, 2021. |
| url |
https://repositorio.ufrn.br/handle/123456789/31964 |
| dc.language.iso.fl_str_mv |
por |
| language |
por |
| dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
| eu_rights_str_mv |
openAccess |
| dc.publisher.none.fl_str_mv |
Universidade Federal do Rio Grande do Norte |
| dc.publisher.program.fl_str_mv |
PROGRAMA DE PÓS-GRADUAÇÃO EM FÍSICA |
| dc.publisher.initials.fl_str_mv |
UFRN |
| dc.publisher.country.fl_str_mv |
Brasil |
| publisher.none.fl_str_mv |
Universidade Federal do Rio Grande do Norte |
| dc.source.none.fl_str_mv |
reponame:Repositório Institucional da UFRN instname:Universidade Federal do Rio Grande do Norte (UFRN) instacron:UFRN |
| instname_str |
Universidade Federal do Rio Grande do Norte (UFRN) |
| instacron_str |
UFRN |
| institution |
UFRN |
| reponame_str |
Repositório Institucional da UFRN |
| collection |
Repositório Institucional da UFRN |
| bitstream.url.fl_str_mv |
https://repositorio.ufrn.br/bitstream/123456789/31964/2/Variabilitypropertiesactive_Belete_2021.pdf.txt https://repositorio.ufrn.br/bitstream/123456789/31964/3/Variabilitypropertiesactive_Belete_2021.pdf.jpg https://repositorio.ufrn.br/bitstream/123456789/31964/1/Variabilitypropertiesactive_Belete_2021.pdf |
| bitstream.checksum.fl_str_mv |
95c279ca10f08aa16be1cac889fcb46e 1d9d6a842d261a1a0083a0223fdaa36b 2e14ba05d4852b8d6ffe9ba1fab627da |
| bitstream.checksumAlgorithm.fl_str_mv |
MD5 MD5 MD5 |
| repository.name.fl_str_mv |
Repositório Institucional da UFRN - Universidade Federal do Rio Grande do Norte (UFRN) |
| repository.mail.fl_str_mv |
|
| _version_ |
1802117527540596736 |