[Previous] | [Session 117] | [Next]
S. van den Bergh (Dominion Astrophys. Obs.)
Radial velocities of 241 galaxies in, and near, the Hubble Deep Field (astro-ph/0008051), in conjunction HST images in R and I and Palomar Sky Survey images in B, have been used to study galaxy evolution as viewed at restframe blue wavelengths. Unexpectedly these observations show that galaxy morphology is still evolving quite rapidly at the present time. The Hubble tuning fork diagram only describes galaxies with z < 0.5. Grand design spirals and barred spirals are rare at z > 0.3. For z > 0.5 spiral structure is seen to be increasingly chaotic. The frequency of peculiar and interacting galaxies increases rapidly towards larger redshifts. An apparent deficiency of Sc galaxies at z ~ 1 is probably due to the fact that many of such objects are classified as "peculiar", "protogalaxy" and "?".
The author(s) of this abstract have provided an email address for comments about the abstract: sidney.vandenbergh@nrc.ca