Estudo cinemático dos jatos relativísticos dos blazares TXS 0506+056 e PKS 0502+049 e sua relação com a produção de neutrinos

• Autor(a) principal: Sumida, Viktor Yuri Doná
• Data de Publicação: 2021
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório do Centro Universitário Braz Cubas
• Texto Completo: https://repositorio.cruzeirodosul.edu.br/handle/123456789/4137
• topic: Núcleos ativos de galáxias; Blazares; Jatos relativísticos; TXS 0506+056; PKS 0502+049.; Cross-Entropy; Neutrinos; IceCube-170922A; CNPQ::CIENCIAS EXATAS E DA TERRA::ASTRONOMIA::ASTROFISICA ESTELAR

The physical nature of the mechanism responsible for the emission of neutrinos in active galactic nuclei (AGNs) has been matter of debate in the literature, with relativistic jets of radio-loud AGNs as possible candidates to be the sources of high energy neutrinos. On 22 September 2017, the IceCube Neutrino Observatory detected a 290-TeV neutrino from a direction consistente with blazar TXS 0506+056, which which was in a state of enhanced gamma-ray emission. Furthermore, the IceCube reported an excess of neutrinos from the direction of TXS 0506+056 between September 2014 and March 2015, but this association needs additional care considering the presence of a nearby γ-ray source, the FSRQ blazar PKS 0502+049. Motivated by this, we have studied the structures of the objects TXS 0506+056 and PKS 0502+049 on parsec scales through radio interferometric images obtained from the MOJAVE database and the Astrogeo Center. The relativistic nature of these objects is revealed by these images from detecting jets which extend in a direction close to N-S, for TXS 0506+056, and NW-SE, for PKS 0502+049, without the apparent presence of the counter jet. In this work, we analyze the structural characteristics of the components present in these jets (core-component, intensity, etc.) at the frequencies of 8 and 15 GHz with the aid of our statistical method for global optimization Cross-Entropy. Twelve and seven components have been identified respectively in the TXS 0506+056 and PKS 0502+049 jets, with superluminal speeds ranging from 14.4c to 60, 5c, for TXS 0506+056, and from 14.3c to 59.1c, for PKS 0502+049. From the kinematic study of these components, based on the apparent superluminal speeds, the lower limit for the Lorentz factor and the upper limit for the jet viewing angle were estimated, whose values are γmin = 60.5 and φmax = 8.0 ◦ , for TXS 0506+056, and γmin = 59.1 and φmax = 8.0 ◦, for PKS 0502+049. The ejections of new components are associated with gamma-ray flares, where three of which, two on PKS 0502+049 and one on TXS 0506+056, may be correlated with the events detected by the IceCube Observatory.