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(IR) Para Análise Do Complexo IC 5146

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(IR) Para Análise Do Complexo IC 5146 UNIVERSIDADE FEDERAL DO RIO GRANDE DO SUL INSTITUTO DE F´ISICA DEPARTAMENTO DE ASTRONOMIA Uma perspectiva pancrom´atica no infravermelho (IR) para an´alise do complexo IC 5146 ? Nat´alia Amarinho Nunes Tese realizada sob orienta¸c~aodo Prof. Dr. Charles Bonatto e apresentada ao Pro- grama de P´os-Gradua¸c~ao em F´ısica da Universidade Federal do Rio Grande do Sul, como requisito para a obten¸c~aodo t´ıtulode Doutor em Ci^encias. Porto Alegre, RS, Brasil Fevereiro de 2016 ? Trabalho financiado pelo CNPq UNIVERSIDADE FEDERAL DO RIO GRANDE DO SUL INSTITUTO DE F´ISICA DEPARTAMENTO DE ASTRONOMIA A panchromatic view in IR for the analysis of IC 5146 complex ? Nat´alia Amarinho Nunes Tese realizada sob orienta¸c~aodo Prof. Dr. Charles Bonatto e apresentada ao Pro- grama de P´os-Gradua¸c~ao em F´ısica da Universidade Federal do Rio Grande do Sul, como requisito para a obten¸c~aodo t´ıtulode Doutor em Ci^encias. Porto Alegre, RS, Brasil Fevereiro de 2016 ? Trabalho financiado pelo CNPq Agradecimentos E´ tempo de agradecer ... Agrade¸coa todos e a cada um que ficou na torcida, participou (in)diretamente desta etapa! Chego ao final do doutorado em paz comigo mesmo. Sentimento de miss~aocum- prida, mesmo sabendo que a miss~aomaior que chamam de Vida ainda me desafiar´a muitas e muitas vezes. Se sinto isso ´epor ter alcan¸cadoos objetivos que me propus at´eagora. Mas todos sabem o quanto gosto de uma novidade, uma aventura, qualquer coisa que me fa¸caco¸cara cabe¸carefletindo e ponderando pr´ose contras. O mais importante ´edeixar claro que somente sou quem sou e estou onde estou, pois cada um que est´alendo este texto e tantos outros que se perderam na jornada contribuiram para minha educa¸c~ao,forma¸c~ao,elabora¸c~aode princ´ıpios,car´atere at´emesmo a minha personalidade. Gratid~aoa todos! Resumo Ao longo das ´ultimasd´ecadas,observa¸c~oesno IR obtidas pelo telesc´opioespacial Spitzer aumentaram significantemente a popula¸c~aoconhecida de YSOs associados as nuvens moleculares pr´oximas.Com tal censo, estudos recentes t^emcaracterizado estelas PMS e deteminado par^ametrosem diferentes comprimentos de onda. Dada a cobertura restrita de algumas destas nuvens, relativo `assuas regi~oesestendidas, estas popula¸c~oesde YSOs podem representar uma vis~aolimitada da forma¸c~aoes- telar nestas regi~oes.Diante disso, aproveitamos observa¸c~oesno IR m´ediodo WISE, que fornece uma cobertura maior do c´eu, podendo assim apresentar uma maior popula¸c~aorepresentativa de YSO. N´osestendemos o m´etodo de classifica¸c~aobem estabelecido por Allen et al.(2004) para observa¸c~oesdo Spitzer e WISE. Adotamos a fotometria 2MASS como sistema padr~aopara compara¸c~oes.Al´emdo aglomerado embebido IC 5146, n´osfornecemos uma vis~aoem diversas bandas fotom´etricasdos 5 novos aglomerados estelares embebidos e sua vizinhan¸ca. Em suma, a an´alise da amostra envolve os seguintes passos: (i) extra¸c~aofotom´etrica(2MASS, Spitzer e WISE) de uma regi~aocircular; (ii) descontamina¸c~aode estrelas de campo para refor¸cara morfologia intr´ınsecado diagrama Cor-magnitude (CMD) (essencial para determinar o avermelhamento, idade e dist^anciado Sol); e (iii) constru¸c~aode fil- tros cor-magnitude, para os perfis radiais de densidade estelar (RDPs). Os perfis foram constru´ıdoscom estrelas selecionadas ap´osa aplica¸c~aofiltro cor-magnitude (CM) sobre a fotometria observada, o qual isola estrelas com grande probabilidade de serem membros do aglomerado. A dist^anciado IC 5146 foi estimada num valor de 1190 ± 70 pc do Sol. Tal dist^anciatem sido quest~aode debate na literatura. Entretanto, as dist^anciase as incertezas fotom´etricasdos 5 NBBs sugerem que eles est~aoassociados fisicamente. Estes novos YSOs descobertos, IC 5146 e Streamer possuem idade de 5 ± 3Myr. Conclu´ımosque todo o complexo IC 5146 sugere-nos uma concord^ancia morfol´ogicaassociada com o processo de forma¸c~aoestelar. Abstract Throughout the last decade sensitive infrared observations obtained by the Spitzer Space Telescope significantly increased the known population of YSOs associated with nearby molecular clouds. With such a census recent studies have characterized pre-main sequence stars (PMS) and determined parameters from different wave- lengths. Given the restricted Spitzer coverage of some of these clouds, relative to their extended regions, these YSO populations may represent a limited view of star formation in these regions. We are taking advantage of mid-infrared observations from the NASA Wide Field Infrared Survey Explorer (WISE), which provides an all sky view and therefore full coverage of the nearby clouds, to assess the degree to which their currently known YSO population may be representative of a more com- plete population. We extend the well established classification method of the Spitzer Legacy teams to archived WISE observations. We have adopted 2MASS photometry as a \standard catalogue" for comparisons. Besides the massive embedded cluster IC 5146 we provide a multiband view of five new embedded clusters in its surroun- dings that we discovered with WISE. In short, the analysis involves the following for the presently studied cluster sample: (i) extraction of 2MASS/WISE/Spitzer photometry in a wide circular region; (ii) field-star decontamination to enhance the intrinsic Colour-magnitude diagram (CMD) morphology (essential for a proper derivation of reddening, age, and distance from the Sun); and (iii) construction of Colour-magnitude filters, for more contrasted stellar radial density profiles (RDPs). Conte´udo Conte´udo IV Lista de Figuras VI 1 Introdu¸c~ao 2 1.1 Propriedades observadas nas nuvens de forma¸c~aoestelar . 3 1.1.1 S´ıtiosde forma¸c~aoestelar . 3 1.1.2 Estrutura das nuvens moleculares . 4 1.1.3 O papel da turbul^enciae do campo magn´etico . 6 1.1.4 Evolu¸c~aoda Nuvem e o Tempo de Vida . 9 1.2 Fragmenta¸c~aodas Nuvens de Forma¸c~aoEstelar . 10 1.2.1 Instabilidade Gravitacional . 11 1.2.2 Efeitos de rota¸c~aoe campos magn´eticos. 14 1.2.3 O papel da turbul^encia. 15 1.3 Colapso dos n´ucleosdas nuvens pr´e-estelares . 17 1.3.1 Condi¸c~oes iniciais . 17 1.3.2 Colapso esf´erico. 18 1.3.3 Colapso com rota¸c~ao . 21 1.3.4 Colapso com campos magn´eticos . 23 1.4 Fase opticamente espessa . 25 1.5 Objetivos do trabalho . 27 2 Quest~oesAbertas na Evolu¸c~aode Estrelas PMS de Baixa Massa 29 2.1 Alguns problemas interessantes . 30 2.1.1 Estrelas de baixa massa como tra¸cadorasda forma¸c~aoestelar . 30 2.1.2 Estrelas de baixa massa como tra¸cadorasde idade . 30 2.1.3 Obten¸c~aoda IMF e distribui¸c~aode idade . 31 2.1.4 Fase protoestelar e \birthline"(linha do nascimento) . 32 2.1.5 Localiza¸c~aodas Trajet´orias . 32 IV CONTEUDO´ V 2.1.6 Atmosfera n~ao-cinzae convec¸c~ao . 33 2.1.7 O papel do campo magn´etico . 34 2.1.8 Deple¸c~aodo l´ıtio . 39 3 Dados Fotom´etricose a Lei de Extin¸c~aoInterestelar 42 3.1 Import^anciadas observa¸c~oesno IR (infravermelho) . 42 3.2 2MASS - The Two Micron All Sky Survey . 43 3.3 WISE -Wide field Infrared Survey Explorer . 44 3.4 Spitzer Space Telescope . 45 3.5 A lei de extin¸c~aointerestelar . 46 4 Resultados e Discuss~ao 54 5 Conclus~oese Perspectivas 74 5.1 Perspectivas . 75 5.2 Testes Observacionais para estrelas PMS . 79 5.3 Estrelas de baixa massa e an~asmarrons: 0:5 M ≤ M? ≤ 1:5 M . 80 5.4 Estrelas de massa intermedi´aria:1:5 ≤ M? ≤ 8:0 e a faixa de insta- M bilidade . 82 5.5 Estrelas massivas: M? & 8:0 M ..................... 84 5.6 Aglomerados versus estrelas massivas isoladas . 85 5.7 A fun¸c~aode massa inicial - IMF . 86 5.7.1 Um pouco de hist´oria. 86 5.7.2 Atuais paradigmas para IMF . 87 5.7.3 A IMF de aglomerados jovens e associa¸c~oes. 91 5.8 Discos circunstelares . 92 5.8.1 Forma¸c~aodo disco . 93 5.8.2 Propriedades dos discos proto-planet´arios . 95 5.9 Massa . 96 5.9.1 Raio . 97 5.10 Estrutura . 99 5.10.1 Composi¸c~ao . 102 Ap^endiceB: Artigo 114 Nunes, Bonatto & Bica, 2015 . 114 Refer^enciasBibliogr´aficas 115 Lista de Figuras 2.1 Imagem do efeito Zeeman-Doppler por Hussain et al., 2007. O pai- nel superior ´eum mapa local, com o preto indicando a presen¸cada mancha solar e o branco, a fotosfera nua. O painel do meio e infe- rior s~aomapas dos campos radial e azimutal, respectivamente; azul e vermelho indicam ±1300G, e representam a estrutura do campo caracter´ısticoda AB Dor. 36 2.2 Este desenho ilustra como o imageamento Doppler funciona. Quando uma mancha cruza a superf´ıcieestelar numa dada latitude, h´aum decr´escimono fluxo cont´ınuo observado, contribuindo para a per- man^enciaem toda absor¸c~aoque ´eo deslocamento Doppler. Tomando uma s´erietemporal do espectro a movimenta¸c~aoe localiza¸c~aodas manchas pode ser determinada pela modelagem destas contribui¸c~oes das linhas de absor¸c~aoestelares. Cr´editoda imagem : A. Collier Cameron. 37 2.3 Este modelo para a estrela AB Dor da Jardine et al.,(2002) ilustra o efeito da temperatura coronal a partir da emiss~aoraio X. A figura a esquerda ´eo campo magn´eticoextrapolado em larga escala pelo imageamento superficial Zeeman-Doppler. Ao centro,uma imagem da emiss~aode raio X ´egerada usando uma temperatura de 107K e uma densidade de 4 × 108cm−3.
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