Metallicity gradients in the disks of SO galaxies

Extract

The gaseous component in disks of spiral galaxies generally shows strong metallicity gradients of about 0.2 dex per scale length of the disk (e.g. Edmunds and Pagel 1984, MNRAS 211,507). Current models explain these gradients by a radially varying ratio of stellar density to gas density, possibly coupled with infall of gas from outside and radial gas flows in the disk (Lacey and Fall 1985, Ap.J. 290,154). It follows from these models that the final metallicity gradient (i.e. the gradient after infall has ceased and all gas has been locked into stars) should be quite shallow.