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@MastersThesis{Targon:2008:InCaMa,
               author = "Targon, Cristiane Godoy",
                title = "A influ{\^e}ncia do campo magn{\'e}tico interestelar na 
                         forma{\c{c}}{\~a}o estelar associada a jatos {\'o}pticos",
               school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
                 year = "2008",
              address = "S{\~a}o Jos{\'e} dos Campos",
                month = "2008-08-01",
             keywords = "Campo magn{\'e}tico, forma{\c{c}}{\~a}o estelar, jatos, meio 
                         interestelar, objetos herbig-haro, polarimetria, magnetic field, 
                         star formation, jets, outflows, interstellar medium, herbig-haro 
                         objects, polarimetry.",
             abstract = "Em regi{\~o}es de forma{\c{c}}{\~a}o estelar de nossa 
                         Gal{\'a}xia, encontramos os objetos Herbig-Haro, que resultam do 
                         choque supers{\^o}nico de efluxos (outflows) originados em 
                         estrelas jovens com o meio interestelar adjacente. O mecanismo que 
                         se acredita ser respons{\'a}vel pela gera{\c{c}}{\~a}o dos 
                         jatos (processo de acelera{\c{c}}{\~a}o 
                         magneto-centr{\'{\i}}fuga) envolve a presen{\c{c}}a de um campo 
                         magn{\'e}tico possivelmente remanescente do colapso gravitacional 
                         que deu origem ao sistema disco-protoestrela. A 
                         propaga{\c{c}}{\~a}o do jato no MI tamb{\'e}m pode ser 
                         influenciada pelas caracter{\'{\i}}sticas do campo 
                         magn{\'e}tico interestelar. Este trabalho {\'e} um estudo 
                         observacional baseado em polarimetria {\'o}ptica CCD para a 
                         procura de correla{\c{c}}{\~o}es entre as 
                         caracter{\'{\i}}sticas do campo magn{\'e}tico do meio 
                         interestelar nas vizinhan{\c{c}}as de objetos Herbig-Haro e as 
                         propriedades desses objetos e de suas fontes centrais. Nossa 
                         amostra {\'e} composta de 28 campos contendo 1 ou mais objetos 
                         Herbig-Haro. Os resultados obtidos foram: o alinhamento entre a 
                         geometria do objeto estelar jovem e o campo magn{\'e}tico depende 
                         da idade do objeto, sendo que {\'e} observado alinhamento para 
                         objetos de Classe 0 e I, mas n{\~a}o para objetos de Classe II e 
                         III; jatos mais extensos tendem a ser perpendiculares ao campo 
                         magn{\'e}tico do meio interestelar; a dispersao m{\'e}dia do 
                         campo magn{\'e}tico do meio interestelar {\'e} maior para 
                         objetos mais evolu{\'{\i}}dos, evidenciando que a 
                         forma{\c{c}}{\~a}o estelar deve transferir momentum para o meio; 
                         objetos de maior massa tendem a se localizar em locais com maior 
                         dispersao do campo magn{\'e}tico, sendo prov{\'a}vel que essa 
                         maior dispersao seja uma caracter´{\'y}stica da regiao anterior 
                         {\`a} forma{\c{c}}{\~a}o estelar de alta massa, 
                         influenciando-a; a polariza{\c{c}}{\~a}o m{\'e}dia dos campos 
                         cresce com o avermelhamento em regi{\~o}es de baixa massa, mas 
                         decresce em regi{\~o}es de alta massa. ABSTRACT: Herbig-Haro 
                         objects result from the shocks of outflows from young stellar 
                         objects with the surrounding interstellar medium of our Galaxy. 
                         The mechanism believed to be responsible for the generation of 
                         jets (magneto-centrifugal acceleration) involves the presence of a 
                         magnetic field. It can be remnant from the interstellar magnetic 
                         field in the parent molecular cloud from which the protostellar 
                         object has been formed. Moreover, the interstellar magnetic field 
                         may influence the outflow propagation. We present an optical 
                         polarimetric study for the search of correlations between the 
                         interstellar magnetic field and the characteristics of Herbig-Haro 
                         objects and its central sources. Our sample is composed of 28 
                         fields having one or more Herbig- Haro objects. We have found that 
                         there is an alignment between the jet and the interstellar 
                         magnetic field for Class 0 and Class I objects, but not for Class 
                         II and Class III objects. The most extended jets in our sample 
                         tend to be perpendicular to the magnetic field. The average 
                         dispersion of the magnetic field in the studied regions is larger 
                         for older objects, showing that the star formation process can 
                         transfer momentum to the medium. From a point of view of the mass 
                         of the central source, larger magnetic field dispersions are found 
                         in regions containing high mass objects. We suggest that the 
                         observed dispersion is a characteristic of the region prior to 
                         star formation, playing a role on the collapse of this kind of 
                         object. The mean interstellar polarization grows with extinction 
                         in low mass star forming regions, but decreases in the high mass 
                         ones. It could be explained by a smaller polarizing efficiency in 
                         these regions.",
            committee = "Boas, Jos{\'e} Williams dos Santos (presidente) and 
                         Rodrigu{\^e}s, Cl{\'a}udia Vilega (orientadora) and Cerqueira, 
                         Adriano Hoth and Franco, Gabriel Armando Pellegatti",
           copyholder = "SID/SCD",
         englishtitle = "The role of the interstellar magnetic field in the star formation 
                         associated to optical jets",
             language = "pt",
                pages = "163",
                  ibi = "6qtX3pFwXQZGivnK2Y/UNqrs",
                  url = "http://urlib.net/rep/6qtX3pFwXQZGivnK2Y/UNqrs",
           targetfile = "paginadeacesso.htm",
        urlaccessdate = "24 jan. 2021"
}


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