  Magain et al. (2005) argued that the host galaxy of the quasar in HE0450-2958
is substantially under-luminous given the likely mass of its nuclear black
hole. Using kinematical information from the spectra of the quasar and the
companion galaxy, an ultra-luminous infrared galaxy, we test the hypothesis
that the black hole powering the quasar was ejected from the companion galaxy
during a merger. We find that the ejection model can be securely ruled out,
since the kick velocity required to remove the black hole from the galaxy is
greater than about 500 km/s, inconsistent with the presence of narrow emission
line gas at the same redshift as the quasar nucleus. We also show that the
quasar in HE0450-2958 has the spectral characteristics of a narrow-line Seyfert
1 galaxy and calculate a mass for its black hole that is roughly an order of
magnitude smaller than estimated by Magain et al. The predicted luminosity of
the host galaxy is then consistent with the upper limits inferred by those
authors.
