Study of quasar host galaxies combining HST/ACS images and VLT Spectroscopy

We present the results of a study of the host galaxies of a few bright low redshift quasars, based on a combination of high resolution HST/ACS images with deep VLT spectra. Using a version of the MCS deconvolution algorithm specially adapted to HST images, the light from the central point source can be efficiently removed, which allows to study the environment of the quasar down to a few hundreds of parsecs from the center. In a similar way, the spectra can be separated into a quasar contribution and a spatialy resolved slit spectrum of the host galaxy. Combinig the images and spectra allows to carry out a detailed analysis of the immediate environment of the quasar: excitation and ionisation state of the gas, dynamics... Up to now, this method has been applied to six quasars, including the peculiar HE0450-2958 for which no host galaxy could be detected.