Massive Stars
Mostrando 1-9 de 9 artigos, teses e dissertações.
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1. Formação estelar no complexo de nuvens moleculares em Monoceros / Star Formation in the Molecular Cloud Complex in Monoceros
We compare two molecular clouds of the Monoceros Complex in order to study their physical conditions related to the early stages of star formation. The selected clouds, Rosette (RMC) and Monoceros R2 (Mon R2), are interesting regions due to their characteristics that may be confronted with the hypothesis of star formation triggered by high velocity clouds (H
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 04/05/2012
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2. Formação e evolução de galáxias: populações estelares na Via Láctea, galáxias elípticas e propriedades de galáxias em grupos / Galaxy Formation and Evolution: From the Milky Way to Galaxies in Groups
Understanding the way galaxies form and evolve throughout the cosmic time remains one of the greatest challenges of modern cosmology. Several processes are known to play a role in the formation of galaxies, such as feedback from supernovae and active galactic nuclei, chemical and dynamical evolution and environmental effects. This thesis encompasses these pr
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 13/03/2012
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3. Atividade cromosférica induzida por planetas extrasolares gigantes
In the present work, we have analyzed the behavior of the chromospheric activity of stars with planets, as a function of different planetary parameters, searching for possible effects of planets on the chromosphere of the hosting star. For this study we have selected a sample of 73 main sequence stars with planets, of spectral types F, G and K. Our analysis
Publicado em: 2010
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4. Análise multi-espectral dos eventos cíclicos de Carinae / Multi-spectral analysis of the cyclic events of Eta Carinae
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 wi
Publicado em: 2009
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5. Electron and positron capture rates on 55Co in stellar matter
55Co is not only present in abundance in presupernova phase but is also advocated to play a decisive role in the core collapse of massive stars. The spectroscopy of electron capture and emitted neutrinos yields useful information on the physical conditions and stellar core composition. B(GT) values to low-lying states are calculated microscopically using the
Brazilian Journal of Physics. Publicado em: 2007-12
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6. Cold and dense perturbative Yukawa theory with massive fermions
Recent results for the two-loop thermodynamic potential of QCD at finite density have shown that nonzero quark mass corrections to the pressure are relevant and can dramatically affect the structure of compact stars. Motivated by these findings, we consider a simple toy model - cold and dense Yukawa theory - to study the effects of finite fermion masses on t
Brazilian Journal of Physics. Publicado em: 2007-03
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7. "Dusty Plasmas: stellar winds and the interstellar medium" / "Plasmas empoeirados: ventos estelares e o meio interestelar"
In this work, we firstly discuss the propagation of Alfvén waves in dusty plasmas found in several astrophysical environments. The wave dispersion relation is modified giving rise to new damping mechanisms. There are in the literature observational data indicating the presence of dust near the surface of cool giant and supergiant stars. We developed a stell
Publicado em: 2005
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8. Integral field spectroscopy of the Homunculus nebula / Espectroscopia de campo integral do Homúnculo de eta Carinae
The Homunculus nebula was mapped using the integral field technique and the results are presented in this dissertation. The observations were obtained in the J band in the range from 10620 Å to 12960 Å using the CIRPASS s IFU, which contains 499 hexagonal lenses. The spatial sampling is 0,25"/lens and the spectral resolution, set to R=3200. The [Fe II]
Publicado em: 2005
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9. Extrasolar planets
The first known extrasolar planet in orbit around a Sun-like star was discovered in 1995. This object, as well as over two dozen subsequently detected extrasolar planets, were all identified by observing periodic variations of the Doppler shift of light emitted by the stars to which they are bound. All of these extrasolar planets are more massive than S
The National Academy of Sciences.