Calibrating stellar velocity dispersions based on spatially-resolved
  h-band spectra for improving the m-sigma relation
  To calibrate stellar velocity dispersion measurements from optical and
near-IR stellar lines, and to improve the black hole mass (MBH)- stellar
velocity dispersion (sigma) relation, we measure stellar velocity dispersions
based on high quality H-band spectra for a sample of 31 nearby galaxies, for
which dynamical MBH is available in the literature. By comparing velocity
dispersions measured from stellar lines in the H-band with those measured from
optical stellar lines, we find no significant difference, suggesting that
optical and near-IR stellar lines represent the same kinematics and that dust
effect is negligible for early-type galaxies. Based on the spatially-resolved
rotation and velocity dispersion measurements along the major axis of each
galaxy, we find that a rotating stellar disk is present for 80% of galaxies in
the sample. For galaxies with a rotation component, velocity dispersions
measured from a single aperture spectrum can vary by up to ~20%, depending on
the size of the adopted extraction aperture. To correct for the rotational
broadening, we derive luminosity-weighted velocity dispersion within the
effective radius of each galaxy, providing uniformly measured velocity
dispersions to improve the MBH-sigma relation.
