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Dynamical properties of two-component galaxy models whose stellar density distribution is described by a gamma-model while the total density distribution has a pure r^(-2) profile, are presented. The orbital structure of the stellar component is described by Osipkov-Merritt anisotropy, while the dark matter halo is isotropic. After a description of minimum halo models, the positivity of the phase-space density (the model consistency) is investigated, and necessary and sufficient conditions for consistency are obtained analytically as a function of the stellar inner density slope gamma and anisotropy radius. The explicit phase-space distribution function is recovered for integer values of gamma, and it is shown that while models with gamma>4/17 are consistent when the anisotropy radius is larger than a critical value (dependent on gamma), the gamma=0 models are unphysical even in the fully isotropic case. The Jeans equations for the stellar component are then solved analytically; in addition, the projected velocity dispersion at the center and at large radii are also obtained analytically for generic values of the anisotropy radius, and it is found that they are given by remarkably simple expressions. The presented models, even though highly idealized, can be useful as starting point for more advanced modeling of the mass distribution of elliptical galaxies in studies combining stellar dynamics and gravitational lensing.
We present MOND (Modified Newtonian Dynamics) fits to 15 rotation curves of LSB galaxies. Good fits are readily found, although for a few galaxies minor adjustments to the inclination are needed. Reasonable values for the stellar mass-to-light ratios
In this study the geometry of gas dominated galaxies in the SPARC database is analyzed in a normalized $(g_{bar},g_{obs})$-space ($g2$-space), where $g_{obs}$ is the observed centripetal acceleration and $g_{bar}$ is the centripetal acceleration as o
Over the last decade it has become clear that there is a decoupling between the old stellar disk and young stellar disk in spiral galaxies. This has led to a scheme for classifying galaxies on the basis of their near-infrared morphology. The near-inf
We present a two-dimensional multi-component photometric decomposition of 404 galaxies from the CALIFA Data Release 3. They represent all possible galaxies with no clear signs of interaction and not strongly inclined in the final CALIFA data release.
The fully analytical solution for isothermal Bondi accretion on a black hole (MBH) at the center of two-component Jaffe (1983) galaxy models is presented. In a previous work we provided the analytical expressions for the critical accretion parameter