Galaxies Evolution
Mostrando 13-24 de 28 artigos, teses e dissertações.
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13. Populações estelares em galáxias elípticas: cinemática e indicadores de metalicidade e idade / Stellar populations on elliptical galaxies: kinematic, metallicity and age indicators
O estudo da distribuição interna das populações estelares em galáxias do tipo prematuro fornecem informações fundamentais para testar os seus modelos de formação e evolução químio-dinâmica. Por outro lado, o estudo da dinâmica estelar interna nessas galáxias fornece informações relevantes para prever a forma: esferóide triaxial, oblato ou p
Publicado em: 2002
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14. Investigações sobre as relações de escala dos sistemas estelares auto-gravitantes / Investigations on the scaling relations of self-gravitating stellar systems
We aim in this work to collect several numerical and analitical investigations concerning the origin of the scaling relations of the self-gravitating stellar systems. These relations depend on a very small number of independent physical parameters that reduce and confine the observational constraints to a plane in this parameter space, called the ""Fundament
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 200105
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15. Investigations on the scaling relations of self-gravitating stellar systems / Investigações sobre as relações de escala dos sistemas estelares auto-gravitantes
We aim in this work to collect several numerical and analitical investigations concerning the origin of the scaling relations of the self-gravitating stellar systems. These relations depend on a very small number of independent physical parameters that reduce and confine the observational constraints to a plane in this parameter space, called the ""Fundament
Publicado em: 2001
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16. Investigações sobre as relações de escala dos sistemas estelares auto-gravitantes / Investigations on the scaling relations of self-gravitating stellar systems
Objetivamos neste trabalho reunir algumas investigações de ordem numérica e analítica sobre a origem das relações de escala dos sistemas estelares auto-gravitantes. Estas relações dependem de um número bastante pequeno de parâmetros físicos independentes, que reduzem e confinam os vínculos observacionais a um plano neste espaço de parâmetros, c
Publicado em: 2001
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17. Color Gradients and the Secular Evolutionary Scenario in Late-Type Spiral Galaxies / Gradientes de Cor e o Cenário de Evolução Secular em Galáxias Espirais de Tipo Tardio
Nós realizamos um estudo estatístico do comportamento de perfis de cor em bandas largas (UBV) para 257 galáxias espirais do tipo Sbc, ordinárias e barradas, utilizando dados obtidos através de fotometria fotoelétrica de abertura, disponíveis na literatura (Longo &de Vaucouleurs 1983,1985). Nós determinamos os gradientes de cor (B-V) e (U-B) para as g
Publicado em: 1999
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18. Is redshift-dependent evolution of galaxies a theoretical artifact?
The physical validity of the hypothesis of (redshift-dependent) luminosity evolution in galaxies is tested by statistical analysis of an intensively studied complete high-redshift sample of normal galaxies. The necessity of the evolution hypothesis in the frame of big-bang cosmology is confirmed at a high level of statistical significance; however, this evol
The National Academy of Sciences.
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19. Causes and effects of the first quasars.
The light we observe from the most distant known quasars set out when the Universe was about 200 times denser than it is now and less than one-tenth of its present age. The existence of these objects implies that galaxy formation had already, at that early epoch, proceeded to the stage when massive (>10(8)M[symbol, see text]) objects had accumulated in the c
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20. Dissipative processes in galaxy formation.
A galaxy commences its life in a diffuse gas cloud that evolves into a predominantly stellar aggregation. Considerable dissipation of gravitational binding energy occurs during this transition. I review here the dissipative processes that determine the critical scales of luminous galaxies and the generation of their morphology. The universal scaling relation
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21. Optical evidence for the unification of active galactic nuclei and quasi-stellar objects.
There is a variety of optical evidence for some unification of different types of active galactic nuclei and quasi-stellar objects (QSOs). The case is very strong for the unification of at least some Seyfert galaxies, where polarization data show that the type assigned to the Seyfert galaxy must depend on viewing direction. It has been proposed that Fanaroff
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22. Mapping the universe in three dimensions
The determination of the three-dimensional layout of galaxies is critical to our understanding of the evolution of galaxies and the structures in which they lie, to our determination of the fundamental parameters of cosmology, and to our understanding of both the past and future histories of the universe at large. The mapping of the large scale structur
The National Academy of Sciences of the USA.
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23. Observing the epoch of galaxy formation
Significant observational progress in addressing the question of the origin and early evolution of galaxies has been made in the past few years, allowing for direct comparison of the epoch when most of the stars in the universe were forming to prevailing theoretical models. There is currently broad consistency between theoretical expectations and the ob
The National Academy of Sciences.
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24. Difficulties with unification.
The difficulties perceived in the orientation-based unified scheme models, when confronted with the observational data, are pointed out. It is shown that in meter-wavelength selected samples, which presumably are largely free of an orientation bias, the observed numbers of quasars versus radio galaxies are not in accordance with the expectations of the unifi