Environmental Mechanisms Shaping the Nature of Dwarf Spheroidal Galaxies: The View of Computer Simulations
Figure 7
Shape evolution of the stellar component. The upper panel shows the intermediate-to-major axis ratio, , and the bottom panel presents the minor-to-major axis ratio, . Solid lines correspond to the self-consistent simulation in which tides, ram pressure stripping, and UV background were included throughout the orbital evolution of the dwarf. Dotted lines correspond to the case where the dwarf galaxy was extracted from the simulation just after the gas was removed and evolved in isolation. Dashed lines show results of a test in which approximately 30% of the initial gas mass remains in the galaxy because the absence of the UV background reduces significantly the effectiveness of ram pressure stripping. Thick and thin lines correspond to 10 and 5 Gyr of orbital evolution, respectively (for the extracted dwarf we only show the result after 10 Gyr). The shape of the stellar component changes gradually over time and the presence of UV heating is essential for the shape transformation of thedwarf.
