A Dynamical Miss: A Study of the Discrepancy Between Optical and
  Infrared Kinematics in Mergers
  Recently, controversy has erupted over whether gas-rich spiral-spiral mergers
are capable of forming {\it m$^{*}$} ellipticals. Measurements of
$\sigma$$_{\circ}$ from the 2.29$\micron$ CO band-head for local LIRG/ULIRGs,
suggest they are not. IR-bright mergers are often cited as the best candidates
for forming massive ellipticals, so the recent observations have raised doubts
about both the Toomre Merger Hypothesis and the fundamental assumptions of
$\Lambda$-CDM galaxy formation models. However, kinematics obtained with the
Calcium II Triplet at 8500 {\AA} suggest mergers are forming {\it m} $\ge$ {\it
m$^{*}$} ellipticals. In this work, we show that kinematics derived from the CO
stellar absorption band-head leads to a significant underestimation of the
masses of LIRGs/ULIRGs. This is primarily due to the presence of a young
population affecting CO band-head measurements.
