The Shape of LITTLE THINGS Dwarf Galaxies DDO 46 and DDO 168:
  Understanding the stellar and gas kinematics
  We present the stellar and gas kinematics of DDO 46 and DDO 168 from the
LITTLE THINGS survey and determine their respective Vmax/sigma_z,0 values. We
used the KPNO's 4-meter telescope with the Echelle spectrograph as a long-slit
spectrograph. We acquired spectra of DDO 168 along four position angles by
placing the slit over the morphological major and minor axes and two
intermediate position angles. However, due to poor weather conditions during
our observing run for DDO 46, we were able to extract only one useful data
point from the morphological major axis. We determined a central stellar
velocity dispersion perpendicular to the disk, sigma_z,0, of 13.5+/-8 km/s for
DDO 46 and <sigma_z,0> of 10.7+/-2.9 km/s for DDO 168. We then derived the
maximum rotation speed in both galaxies using the LITTLE THINGS HI data. We
separated bulk motions from non-circular motions using a double Gaussian
decomposition technique and applied a tilted-ring model to the bulk velocity
field. We corrected the observed HI rotation speeds for asymmetric drift and
found a maximum velocity, Vmax, of 77.4 +/- 3.7 and 67.4 +/- 4.0 km/s for DDO
46 and DDO 168, respectively. Thus, we derived a kinematic measure,
Vmax/sigma_z,0, of 5.7 +/- 0.6 for DDO 46 and 6.3 +/- 0.3 for DDO 168.
Comparing these values to ones determined for spiral galaxies, we find that DDO
46 and DDO 168 have Vmax/sigma_z,0 values indicative of thin disks, which is in
contrast to minor-to-major axis ratio studies.
