Structure and Substructure of Galactic Spheroids
  The full spatio-chemo-dynamical structure of galaxies of all types and
environments at low redshift provides a critical accompaniment to observations
of galaxy formation at high redshift. The next decade brings the observational
opportunity to strongly constrain nearby galaxies' histories of star formation
and assembly, especially in the spheroids that comprise the large majority of
the stellar mass in the Universe but have until now been difficult to study. In
order to constrain the pathways to building up the spheroidal "red-sequence",
various standard techniques in photometry and spectroscopy, particularly with
resolved tracer populations like globular clusters and planetary nebulae, can
be scaled up to comprehensive surveys as improved wide-field instrumentation is
increasingly available. At the same time, progress in adaptive optics on giant
telescopes could for the first time permit deep, resolved photometric and
spectroscopic analysis of large samples of individual stars in these systems,
thereby revolutionizing galaxy studies. Strong theoretical support is needed in
order to understand the new observational constraints via detailed modeling and
self-consistent simulations of star and galaxy formation throughout cosmic
time.
