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Observations suggest that the structural parameters of disk galaxies have not changed greatly since redshift 1. We examine whether these observations are consistent with a cosmology in which structures form hierarchically. We use SPH/N-body galaxy-scale simulations to simulate the formation and evolution of Milky-Way-like disk galaxies by fragmentation, followed by hierarchical merging. The simulated galaxies have a thick disk, that forms in a period of chaotic merging at high redshift, during which a large amount of alpha-elements are produced, and a thin disk, that forms later and has a higher metallicity. Our simulated disks settle down quickly and do not evolve much since redshift z~1, mostly because no major mergers take place between z=1 and z=0. During this period, the disk radius increases (inside-out growth) while its thickness remains constant. These results are consistent with observations of disk galaxies at low and high redshift.
Surface-brightness profiles for early-type (S0-Sb) disks exhibit three main classes (Type I, II, and III). Type II profiles are more common in barred galaxies, and most of the time appear to be related to the bars Outer Lindblad Resonance. Roughly ha
The spatial distribution of the HI gas in galaxies holds important clues on the physical processes that shape the structure and dynamics of the interstellar medium (ISM). In this work, we quantify the structure of the HI gas in a sample of 33 nearby
Numerical simulations of planet-disk interactions are usually performed with hydro-codes that -- because they consider only an annulus of the disk, over a 2D grid -- can not take into account the global evolution of the disk. However, the latter gove
This paper develops a general framework for learning interpretable data representation via Long Short-Term Memory (LSTM) recurrent neural networks over hierarchal graph structures. Instead of learning LSTM models over the pre-fixed structures, we pro
We present the analysis of a CCD survey of 31 nearby (<= 110 Mpc) edge-on spiral galaxies. The three-dimensional one-component best fit models provide their disk-scalelengths h and for the first time their disk cut-off radii R_{co}. We confirm for th