Nesta tese foi feito um estudo dos eventos cíclicos em Carinae em diversas faixas espectrais. A presença de um buraco na região polar do Homúnculo foi confirmada pelos mapas de velocidade da linha do [Fe II] 12567. A componente em emissão da linha do He I 10830, detectada na linha de visada do lóbulo NW e que apresenta velocidades negativas, foi mapeada e está contida no plano equatorial. Foi observado que durante um período de 206 dias, centrado na fase zero, a linha do He I 10830 apresenta um aumento na velocidade máxima da componente em absorção, atingindo 1800 km/s. Tal comportamento favorece orientações orbitais onde a passagem pelo periastro ocorre próximo à oposição. O Pequeno Homúnculo apresenta a mesma distribuição espacial da emissão em rádio e, considerando que esta seja proveniente principalmente da secundária, o fluxo de fótons no contínuo de Lyman é compatível com uma estrela de tipo espectral O5.5O7. A variabilidade das componentes largas e estreitas das linhas em diversas faixas espectrais apresenta um período bem definido (2022.1±0.6 dias) e extremamente estável ao longo dos últimos 60 anos, sendo que as variações observadas no período são devido aos erros nas medidas. Utilizando a componente estreita da linha do He I 6678 foi possível determinar a fase zero do ciclo #11 (T0=2452819.8). Os eventos espectroscópicos são compostos de dois regimes: um de variações lentas e outro de colapso. A primeira é revelada por variações lentas no nível de ionização do meio circunstelar ao longo de todo o ciclo e está associada a variações graduais no cone de choque dos ventos (abertura angular e conteúdo). O regime de colapso é observado ao redor do mínimo e é causado por um colapso temporário do cone de choque. Os fenômenos de alta energia são sensíveis somente ao regime de colapso, enquanto os de baixa energia, ao de variação lenta. Os fenômenos que envolvem energias intermediárias, respondem aos dois regimes. Foi observado uma anti-correlação entre a linha do Fe II 6455 e a do He I 7065, indicando que a primeira é formada nas regiões mais externas do vento da primária e a segunda, na secundária ou no cone de choque dos ventos. A curva de luz do He II 4686 apresenta dois picos antes da fase zero e outro logo após. Os dois picos antes do mínimo apresentam uma correlação com os picos na faixa dos raios-X, porém estes ocorrem 16.5 dias antes daqueles. O mecanismo mais provável para explicar a luminosidade observada do He II 4686 é a produção de fótons com 1215 Å através do fluxo de fótons na faixa do ultra-violeta extremo/raios-X moles produzidos na região próxima ao ápex do cone de colisão dos ventos. Como este mecanismo é extremamente sensível à densidade do meio, a região mais favorável para produzir a luminosidade observada do He II 4686 é a região do cone de choque voltada para a primária. / In this thesis, a multi-wavelength study on the cyclic events of Eta Carinae was performed. The presence of a hole in the polar region of the Homunculus was confirmed by the velocity maps of the [Fe II] 12567 line. The blue-shifted component of the He I 10830, detected towards the NW lobe, was mapped and it is in the equatorial plane. It was observed that within a short period of 206 days, centered on phase zero, the He I 10830 line shows an increase in the maximum velocity of the absorption component, which reaches up to -1800 km/s. Such behavior favors orbital orientation with periastron passage around oposition. The Little Homunculus shows the same spatial distribution as the radio emission and considering that the radio flux comes mainly from the secondary, then the photon flux in the Lyman continuum is comparable to a star with spectral type in the range O5.5-O7. The variability of the narrow and broad lines from many spectral regions shows a well-defined period (2022.1+/-0.6 days), which is also extremely stable along the last 60 years, during which the observed variations in the period are due to measurement errors. Using the narrow component of the He I 6678 it was possible to determine the phase zero of the cycle #11 (T_0=2452819.8). The spectroscopic events are a combination of two components: slow variation and collapse. The former is revealed by slow changes in the ionization level of circunstellar matter across the whole cycle and is associated to gradual changes in the wind-wind collision shock-cone (angular opening and gaseous content). The collapse component is restricted to around the minimum and is caused by a temporary collapse of the wind-wind collision shock. High-energy phenomena are sensitive only to the collapse component, while low-energy only to the slow variation component. Intermediate-energy phenomena are sensitive to both components. It was observed an anti-correlation between the Fe II 6455 and He II 7065, suggesting that the former is formed in the outer parts of the primary\'s wind, while the latter is associated to the secondary or to the wind-wind shock cone. The lightcurve of He II 4686 shows two peaks before phase zero and another one short after it. The two peaks before phase zero are correlated to the peaks seen in the X-rays. However, the X-ray peaks occur 16.5 days before those seen in the He II 4686 lightcurve. The most likely mechanism to explain the observed peak luminosity of the He II 4686 is the creation of ~1215 Angstroms photons by the extreme ultra-violet/soft X-rays photons, which are produced near the apex of the wind-wind shock-cone. Since this mechanism is extremely sensitive to the density, the most likely region to form the observed peak luminosity of the He II 4686 is on the primary\'s side of the wind-wind shock-cone.

Nesta tese foi feito um estudo dos eventos cíclicos em Carinae em diversas faixas espectrais. A presença de um buraco na região polar do Homúnculo foi confirmada pelos mapas de velocidade da linha do [Fe II] 12567. A componente em emissão da linha do He I 10830, detectada na linha de visada do lóbulo NW e que apresenta velocidades negativas, foi mapeada e está contida no plano equatorial. Foi observado que durante um período de 206 dias, centrado na fase zero, a linha do He I 10830 apresenta um aumento na velocidade máxima da componente em absorção, atingindo 1800 km/s. Tal comportamento favorece orientações orbitais onde a passagem pelo periastro ocorre próximo à oposição. O Pequeno Homúnculo apresenta a mesma distribuição espacial da emissão em rádio e, considerando que esta seja proveniente principalmente da secundária, o fluxo de fótons no contínuo de Lyman é compatível com uma estrela de tipo espectral O5.5O7. A variabilidade das componentes largas e estreitas das linhas em diversas faixas espectrais apresenta um período bem definido (2022.1±0.6 dias) e extremamente estável ao longo dos últimos 60 anos, sendo que as variações observadas no período são devido aos erros nas medidas. Utilizando a componente estreita da linha do He I 6678 foi possível determinar a fase zero do ciclo #11 (T0=2452819.8). Os eventos espectroscópicos são compostos de dois regimes: um de variações lentas e outro de colapso. A primeira é revelada por variações lentas no nível de ionização do meio circunstelar ao longo de todo o ciclo e está associada a variações graduais no cone de choque dos ventos (abertura angular e conteúdo). O regime de colapso é observado ao redor do mínimo e é causado por um colapso temporário do cone de choque. Os fenômenos de alta energia são sensíveis somente ao regime de colapso, enquanto os de baixa energia, ao de variação lenta. Os fenômenos que envolvem energias intermediárias, respondem aos dois regimes. Foi observado uma anti-correlação entre a linha do Fe II 6455 e a do He I 7065, indicando que a primeira é formada nas regiões mais externas do vento da primária e a segunda, na secundária ou no cone de choque dos ventos. A curva de luz do He II 4686 apresenta dois picos antes da fase zero e outro logo após. Os dois picos antes do mínimo apresentam uma correlação com os picos na faixa dos raios-X, porém estes ocorrem 16.5 dias antes daqueles. O mecanismo mais provável para explicar a luminosidade observada do He II 4686 é a produção de fótons com 1215 Å através do fluxo de fótons na faixa do ultra-violeta extremo/raios-X moles produzidos na região próxima ao ápex do cone de colisão dos ventos. Como este mecanismo é extremamente sensível à densidade do meio, a região mais favorável para produzir a luminosidade observada do He II 4686 é a região do cone de choque voltada para a primária. / In this thesis, a multi-wavelength study on the cyclic events of Eta Carinae was performed. The presence of a hole in the polar region of the Homunculus was confirmed by the velocity maps of the [Fe II] 12567 line. The blue-shifted component of the He I 10830, detected towards the NW lobe, was mapped and it is in the equatorial plane. It was observed that within a short period of 206 days, centered on phase zero, the He I 10830 line shows an increase in the maximum velocity of the absorption component, which reaches up to -1800 km/s. Such behavior favors orbital orientation with periastron passage around oposition. The Little Homunculus shows the same spatial distribution as the radio emission and considering that the radio flux comes mainly from the secondary, then the photon flux in the Lyman continuum is comparable to a star with spectral type in the range O5.5-O7. The variability of the narrow and broad lines from many spectral regions shows a well-defined period (2022.1+/-0.6 days), which is also extremely stable along the last 60 years, during which the observed variations in the period are due to measurement errors. Using the narrow component of the He I 6678 it was possible to determine the phase zero of the cycle #11 (T_0=2452819.8). The spectroscopic events are a combination of two components: slow variation and collapse. The former is revealed by slow changes in the ionization level of circunstellar matter across the whole cycle and is associated to gradual changes in the wind-wind collision shock-cone (angular opening and gaseous content). The collapse component is restricted to around the minimum and is caused by a temporary collapse of the wind-wind collision shock. High-energy phenomena are sensitive only to the collapse component, while low-energy only to the slow variation component. Intermediate-energy phenomena are sensitive to both components. It was observed an anti-correlation between the Fe II 6455 and He II 7065, suggesting that the former is formed in the outer parts of the primary\'s wind, while the latter is associated to the secondary or to the wind-wind shock cone. The lightcurve of He II 4686 shows two peaks before phase zero and another one short after it. The two peaks before phase zero are correlated to the peaks seen in the X-rays. However, the X-ray peaks occur 16.5 days before those seen in the He II 4686 lightcurve. The most likely mechanism to explain the observed peak luminosity of the He II 4686 is the creation of ~1215 Angstroms photons by the extreme ultra-violet/soft X-rays photons, which are produced near the apex of the wind-wind shock-cone. Since this mechanism is extremely sensitive to the density, the most likely region to form the observed peak luminosity of the He II 4686 is on the primary\'s side of the wind-wind shock-cone.

Thesis (Ph.D.) - University of Maryland. / "Dissertation directed by Professor Doug Currie, Department of Physics." Includes bibliographical references (p. 260-269).

We analyse eight epochs of Hubble Space Telescope H alpha+[N ii] imaging of eta Carinae's outer ejecta. Proper motions of nearly 800 knots reveal that the detected ejecta are divided into three apparent age groups, dating to around 1250 A.D., to around 1550 A.D., and to during or shortly before the Great Eruption of the 1840s. Ejecta from these groups reside in different locations and provide a firm constraint that eta Car experienced multiple major eruptions prior to the nineteenth century. The 1250 and 1550 events did not share the same axisymmetry as the Homunculus; the 1250 event was particularly asymmetric, even one-sided. In addition, the ejecta in the S ridge, which have been associated with the Great Eruption, appear to predate the ejection of the Homunculus by several decades. We detect essentially ballistic expansion across multiple epochs. We find no evidence for large-scale deceleration of the observed knots that could power the soft X-ray shell by ploughing into surrounding material, suggesting that the observed X-rays arise instead from fast, rarefied ejecta from the 1840s overtaking the older dense knots. Early deceleration and subsequent coasting cannot explain the origin of the older outer ejecta - significant episodic mass loss prior to the nineteenth century is required. The time-scale and geometry of the past eruptions provide important constraints for any theoretical physical mechanisms driving eta Car's behaviour. Non-repeating mechanisms such as the merger of a close binary in a triple system would require additional complexities to explain the observations.

The massive evolved star. Carinae is the most luminous star in the Milky Way and has the highest steady wind mass-loss rate of any known star. Radiative transfer models of the spectrum by Hillier et al. predict that Ha is mostly emitted in regions of the wind at radii of 6-60 au from the star (2.5-25 mas at 2.35 kpc). We present diffraction-limited images (FWHM similar to 25 mas) with Magellan adaptive optics in two epochs, showing that. Carinae consistently appears similar to 2.5-3 mas wider in Ha emission compared to the adjacent 643 nm continuum. This implies that the H alpha line-forming region may have a characteristic emitting radius of 12 mas or similar to 30 au, in very good agreement with the Hillier stellar-wind model. This provides direct confirmation that the physical wind parameters of that model are roughly correct, including the mass-loss rate of M= 10(-3)M(circle dot) yr(-1), plus the clumping factor, and the terminal velocity. Comparison of the Ha images (ellipticity and PA) to the continuum images reveals no significant asymmetries at H alpha. Hence, any asymmetry induced by a companion or by the primary's rotation do not strongly influence the global H alpha emission in the outer wind.

We investigate binary hypotheses for the formation of bipolar nebulae using the smoothed particle hydrodynamics code Gadget-2. In the general case, we present a parameter study of mass loss from very simple common envelope models, which seems to show a strongly bipolar trend for sufficiently oblate envelopes and low enough spiral-in injection energy. The density profiles of the envelopes produce differing structure within the ejecta. We also investigate 3 specific bipolar mass loss events. In the case of the outer nebula of SN 1987A, we study the effects of fast polar jets interacting with a pre- existing progenitor wind and find that these are consistent with the observed light echoes from the nebula, in particular for the feature known as ’Napoleon’s Hat’. In the case of Cas A, we briefly study the effects of close binarity on supernova ejecta and suggest the influence of a close, compact companion may lead to at least one jet-like disturbance that may be observable in a supernova remnant. Finally, we study whether a fast bipolar wind, similar to that of Eta Car’s present wind, may inflate ejecta similar to that produced in the common envelope models to a shape consistent with that of Eta Car’s Homunculus Nebula.