Evolution of Spheroid Galaxies Over the Last Half of Cosmic History
Dan McIntosh (UMass)
I will show how large, modern surveys of galaxies are used to understand
the evolution of spheroid systems over the last half of cosmic time. We
find that galaxies with spheroid-dominated light profiles contain most
of the stars in the present-day universe. The bulk of these stars formed
before the universe was half its current age, yet many of the galaxies
in which they reside were assembled more recently in major mergers between
smaller galaxies. Concentrating on the spheroid population provides clues
to overall galaxy evolution. The origin and evolution of galaxies is one
of the main science drivers of NASA's Origins program, the planned James
Webb Space Telescope, and most current and proposed large telescope and
galaxy survey projects.