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`Conspiracy between the dark and the baryonic mater prohibits an unambiguous decomposition of disc galaxy rotation curves into the corresponding components. Several methods have been proposed to counter this difficulty, but their results are widely discrepant. In this paper, I revisit one of these methods, which relies on the relation between the halo density and the decrease of the bar pattern speed. The latter is routinely characterised by the ratio ${cal R}$ of the corotation radius $R_{CR}$ to the bar length $L_b$, ${cal R}=R_{CR}/L_b$. I use a set of $N$-body+SPH simulations, including sub-grid physics, whose initial conditions cover a range of gas fractions and halo shapes. The models, by construction, have roughly the same azimuthally averaged circular velocity curve and halo density and they are all submaximal, i.e. according to previous works they are expected to have all roughly the same ${cal R}$ value, well outside the fast bar range (1.2 $pm$ 0.2). Contrary to these expectations, however, these simulations end up having widely different ${cal R}$ values, either within the fast bar range, or well outside it. This shows that the ${cal R}$ value can not constrain the halo density, nor determine whether galactic discs are maximal or submaximal. I argue that this is true even for early type discs (S0s and Sas).
We select a sample of galaxies from the Sloan Digital Sky Survey Data Release 7 (SDSS-DR7) where galaxies are classified, through visual inspection, as hosting strong bars, weak bars or as unbarred galaxies, and make use of HI mass and kinematic info
In the light of the discovery of numerous (almost) dark galaxies from the ALFALAFA and LITTLE THINGS surveys, we revisit the predictions of Jimenez et al. 1997, based on the Toomre stability of rapidly-spinning gas disks. We have updated the predicti
By means of N-body simulations, we show that radial migration in galaxy disks, induced by bar and spiral arms, leads to significant azimuthal variations in the metallicity distribution of old stars at a given distance from the galaxy center. Metals d
We use cosmological hydrodynamical simulations of the APOSTLE project along with high-quality rotation curve observations to examine the fraction of baryons in {Lambda}CDM haloes that collect into galaxies. This galaxy formation efficiency correlates
(Abridged) Any viable cosmological model in which galaxies interact predicts the existence of primordial and tidal dwarf galaxies (TDGs). In particular, in the standard model of cosmology ($Lambda$CDM), according to the dual dwarf galaxy theorem, the