Galactic Emission
Mostrando 13-21 de 21 artigos, teses e dissertações.
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13. Um mapa da emissão galática em 408 MHz. / A map of the galactic emission at 408 MHz.
We present a map of the Galactic Emission at 408 MHz prepared from the data collected with the radiotelescope of the Galactic Emission Mapping (GEM) project operating in the Owens Valleys desert (CA - USA) in April 1994. A total power receiver was used with the following characteristics: bandwidth of 28 MHz, noise temperature of 112 K, gain of 57. 8 KV-1, an
Publicado em: 2000
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14. Substructures in clusters of galaxies / Estudo de subestruturas em aglomerados de Galáxias
This dissertation presents two methods for the detection of substructures in clusters of galaxies and the results of their application to a group of 4 clusters. In chapters 2 and 3, we remember the main properties of clusters of galaxies and give the definition of substructures. We also try to show why the study of substructures in clusters of galaxies is so
Publicado em: 2000
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15. Optical spectroscopy of obscured active galaxies / Espectroscopia óptica de galáxias ativas obscurecidas
We present in this work a study of obscured Active Galaxies which were identified by Sofia Kirhakos in 1990. She verified that surveys at the optical part of the spectrum are not efficient to identify Seyfert nuclei in galaxies observed edge-on. To overcome this difficulty she proposed a selection criterion in which sources identified by the IRAS satellite t
Publicado em: 1998
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16. Metodos de determinacao de periodicidades em dados astrofisicos: aplicacao ao objeto CZ Aquilae / Methods of determination of periodicities in astrophysical data - Appliocation to object CZ Aquilae
One way of studing an object in astrophysics is with the time series analysis, where we can characterize the behaviour of object in the past and future. To make this analysis, we use period determination methods. We applied five methods to the cataclysmic variable CZ Aquilae, with the goal to find their orbital period. Photometric and spectroscopic data were
Publicado em: 1998
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17. EMISSION-LINE OBJECTS PROJECTED UPON THE GALACTIC BULGE*
Low-dispersion slit spectrograms have been obtained of 34 faint objects that lie in the direction of the galactic bulge and have the Hα line in emission upon a detectable continuum. Eleven of these are certain or probable symbiotic stars. A rough comparison with R CrB stars in the same area suggests that these brightest symbiotics in the bulge have in the m
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18. THE ORIGIN OF NONTHERMAL GALACTIC RADIO EMISSION AND OF PRIMARY COSMIC RAYS
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19. The nuclear region of the spiral galaxy M81.
Very-long-baseline radio interferometry images of the nuclear region of the nearby spiral galaxy M81 reveal the most compact galactic core outside the Galaxy of which the size has been determined: 700 x 300 astronomical units (AU). The observations exclude a starburst or supernova interpretation for the core. Instead they favor an active galactic nucleus. Th
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20. Graviton scattering and matter distribution.
In this model gravitation results from the emission and absorption of quanta (gravitons) that are scattered a few times in crossing a typical galaxy. Many features of the universe can be explained in terms of this model, although theoretical justification for the scattering of gravitons is lacking. Gravitons follow a random walk and diffuse through the outer
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21. Probing active galactic nuclei with H2O megamasers.
We describe the characteristics of the rapidly rotating molecular disk in the nucleus of the mildly active galaxy NGC4258. The morphology and kinematics of the disk are delineated by the point-like watervapor emission sources at 1.35-cm wavelength. High angular resolution [200 microas where as is arcsec, corresponding to 0.006 parsec (pc) at 6.4 million pc]