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Ch. Skokos P. A. Patsis E. Athanassoula 《Monthly notices of the Royal Astronomical Society》2002,333(4):861-870
We investigate the orbital structure in a class of three-dimensional (3D) models of barred galaxies. We consider different values of the pattern speed, of the strength of the bar and of the parameters of the central bulge of the galactic model. The morphology of the stable orbits in the bar region is associated with the degree of folding of the x1 characteristic. This folding is larger for lower values of the pattern speed. The elongation of rectangular-like orbits belonging to x1 and to x1-originated families depends mainly on the pattern speed. A detailed investigation of the trees of bifurcating families in the various models shows that major building blocks of 3D bars can be supplied by families initially introduced as unstable in the system, but becoming stable at another energy interval. In some models without radial and vertical 2:1 resonances we find, except for the x1 and x1-originated families, also families related to the z -axis orbits, which support the bar. Bifurcations of the x2 family can build a secondary 3D bar along the minor axis of the main bar. This is favoured in the slowly rotating bar case. 相似文献
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Miguel A. de Avillez † 《Monthly notices of the Royal Astronomical Society》2000,315(3):479-497
The results of a three-dimensional model for disc–halo interaction are presented here. The model considers explicitly the input of energy and mass by isolated and correlated supernovae in the disc. Once disrupted by the explosions, the disc never returns to its initial state. Instead it approaches a state where a thin H i disc is formed in the Galactic plane, overlaid by thick H i and H ii gas discs with scaleheights of 500 pc and 1–1.5 kpc, respectively. The upper parts of the thick H ii disc (the diffuse ionized medium) act as a disc–halo interface, and its formation and stability are directly correlated to the supernova rate per unit area in the simulated disc. 相似文献
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R. Bacon Y. Copin G. Monnet Bryan W. Miller J.R. Allington-Smith M. Bureau C. Marcella Carollo Roger L. Davies Eric Emsellem Harald Kuntschner Reynier F. Peletier E.K. Verolme P. Tim de Zeeuw 《Monthly notices of the Royal Astronomical Society》2001,326(1):23-35
A new integral-field spectrograph, SAURON, is described. It is based on the TIGER principle, and uses a lenslet array. SAURON has a large field of view and high throughput, and allows simultaneous sky subtraction. Its design is optimized for studies of the stellar kinematics, gas kinematics, and line-strength distributions of nearby early-type galaxies. The instrument design and specifications are described, as well as the extensive analysis software which was developed to obtain fully calibrated spectra, and the associated kinematic and line-strength measurements. A companion paper will report on the first results obtained with SAURON on the William Herschel Telescope. 相似文献
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The SAURON project – III. Integral-field absorption-line kinematics of 48 elliptical and lenticular galaxies 总被引：1，自引：0，他引：1
Eric Emsellem Michele Cappellari Reynier F. Peletier Richard M. McDermid R. Bacon M. Bureau † Y. Copin Roger L. Davies Davor Krajnovi&#; Harald Kuntschner Bryan W. Miller P. Tim de Zeeuw 《Monthly notices of the Royal Astronomical Society》2004,352(3):721-743
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Irina A. Yegorova Paolo Salucci 《Monthly notices of the Royal Astronomical Society》2007,377(2):507-515
We find a new Tully–Fisher-like relation for spiral galaxies holding at different galactocentric radii. This radial Tully–Fisher relation allows us to investigate the distribution of matter in the optical regions of spiral galaxies. This relation, applied to three different samples of rotation curves of spiral galaxies, directly proves that: (i) the rotation velocity of spirals is a good measure of their gravitational potential and both the rotation curve's amplitudes and profiles are well predicted by galaxy luminosity, (ii) the existence of a dark component, less concentrated than the luminous one, and (iii) a scaling law, according to which, inside the disc optical size: M dark / M lum = 0.5( L B /1011 L B ⊙ )−0.7 . 相似文献
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