Clues on Galaxy Disk Evolution from Studies of `Superthin' Spirals
Lynn Matthews (Harvard/CfA)
`Superthins' are a subset of spiral galaxies seen edge-on that exhibit
highly flattened stellar disks, unusually small disk scale heights, and
little or no bulge component. These appear to be among the structurally
simplest and dynamically least evolved disk galaxies observable in the
local universe. Therefore studies of these objects can yield important
insight into the manner in which both internal and external processes
affect the evolution of galactic disks.
I will highlight some recent results from the analysis of multiwavelength
observations of two nearby superthin spirals, with particular emphasis on
sensitive new VLA HI imaging observations. One of these objects is
extremely isolated, while the other is located in a group environment and
in the process of undergoing a minor merger. I will discuss the clues
these observations shed on a variety of phenomena governing the evolution
of galaxy disks, including the origin of warps, disk stability, dynamical
heating, and morphological transformations.
