Near-infrared imaging and spectroscopy of the nuclear region of the
  disturbed Virgo cluster spiral NGC 4438
  We present near-infrared VLT ISAAC imaging and spectroscopy of the peculiar
Virgo galaxy NGC 4438, whose nucleus has been classified as a LINER. The data
are supplemented by mid-infrared imaging, and compared to previous WFPC2 HST
broadband images. Images and position-velocity maps of the [Fe II] and H2 line
emissions are presented and compared with the distribution of the optical
narrow-line region and radio features. Our results show that shocks (possibly
driven by a radio jet) contribute to an important fraction of the excitation of
[Fe II], while X-ray heating from a central AGN may be responsible for the H2
excitation. We address the question whether the outflow has an AGN or a
starburst origin by providing new estimates of the central star formation rate
and the kinetic energy associated with the gas. By fitting a Sersic bulge, an
exponential disc and a compact nuclear source to the light distribution, we
decomposed NGC 4438's light distribution and found an unresolved nuclear source
at 0.8 arcsec resolution with M_K = -18.7 and J-H = 0.69. Our measured bulge
velocity dispersion, 142 km/s, together with the standard M_bh-sigma relation,
suggests a central black hole mass of log(M_bh/Msun) ~ 7.0. The stellar
kinematics measured from the near-infrared CO lines shows a strong peak in the
velocity dispersion of 178 km/s in the central 0.5 arcsec, which is possible
kinematic evidence of a central black hole. We calculated a general expression
for the integrated Sersic profile flux density in elliptical geometry,
including the case of 'disky' isophotes.
