Mariska Kriek
Harvard Smithsonian Center for Astrophysics
The Life Cycle of Massive Galaxies
Similar to the situation at low redshift, the properties of galaxies
beyond z = 2 are strongly correlated. Massive galaxies at this epoch
clearly separate into two classes: the large star-forming galaxies that form
the blue cloud, and the smaller quiescent galaxies on the red sequence. Thus,
it is evident that a Hubble sequence with strongly correlated galaxy
properties is already in place beyond z = 2. Nonetheless, this
sequence does not resemble the local Hubble sequence, as the structures and
morphologies of the z > 2 galaxies are different from those of their
local analogs. While quiescent galaxies are much more compact than nearby
early-type galaxies, massive star-forming galaxies have irregular and clumpy
structures. This raises the question of how this sequence originated, and
subsequently evolves into the galaxy population that we find in the present-day
universe. In this talk I will present our latest results and discuss
the implications for the formation histories of massive galaxies.