Stability of thick two-component galactic discs
نویسندگان
چکیده
منابع مشابه
Stability and Evolution of Galactic Discs
In this review, I discuss just three aspects of the stability and evolution of galactic discs. (1) I first review our understanding of the bar instability and how it can be controlled. Disc galaxies in which the orbital speed does not decrease much towards the centre have no difficulty avoiding bars, even when dark matter makes an insignificant contribution to the inner part of the rotation cur...
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Accretion onto a compact object must occur through a disc when the material has some initial angular momentum. Thin discs and the thicker low radiative efficiency accretion flows (LRAFs) are solutions to this problem that have been widely studied and applied. This is an introduction to these accretion flows within the context of X-ray binaries and cataclysmic variables. Accretion describes the ...
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The analysis of the kinematics of solar neighbourhood stars shows that the low and high metallicity tails of the thin disc are populated by objects which orbital properties suggest an origin in the outer and inner galactic disc, respectively. Signatures of radial migration are identified in various recent samples, and are shown to be responsible for the high metallicity dispersion in the age-me...
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We show that spiral waves in galaxy discs churn the stars and gas in a manner that largely preserves the overall angular momentum distribution and leads to little increase in random motion. Changes in the angular momenta of individual stars are typically as large as ∼ 50% over the lifetime of the disc. The changes are concentrated around the corotation radius for an individual spiral wave, but ...
متن کاملThin and Thick Galactic Disks
Studies of elemental abundances in stars belonging to the thin and the thick disk of our Galaxy are reviewed. Edvardsson et al. (1993) found strong evidence of [α/Fe] variations among F and G main sequence stars with the same [Fe/H] and interpreted these differences as due to radial gradients in the star formation rate in the Galactic disk. Several recent studies suggest, however, that the diff...
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ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 1992
ISSN: 0035-8711,1365-2966
DOI: 10.1093/mnras/256.2.307