Karen L. Masters studies the structure and evolution of galaxies. Her review with Jerry A. Sellwood connects observed spiral arms to the dynamics of galactic disks, comparing proposed mechanisms with observations and numerical numerical simulations.
A visible spiral pattern need not be a permanent set of the same stars. Recurrent patterns can rearrange a galactic disk and increase random stellar motion; continuing activity then depends in part on the dissipative gas component. Their review also used the number of spiral arms to discuss how much mass resides in the thin galactic disk relative to its surrounding halo.[ref]
Spirals in Galaxies by Jerry A. Sellwood and Karen L. Masters. Abstract: gravitational instability, recurring transient spirals, gas dissipation and arm-number constraints
Portrait of Karen L. Masters
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