The quasar without a home: HE0450-2958

(Left) HST image of the z=0.285 quasar HE0450-2958. No obvious host galaxy centred on the quasar is seen. Only a strongly disturbed and star forming companion galaxy is seen near the top of the image. (Right) Same image shown after applying an efficient image sharpening method known as MCS-deconvolution. In contrast to the usual cases, as the ones shown in ESO Press Photo eso0529, the quasar is not situated at the centre of an extended host galaxy, but on the edge of a compact structure, whose spectra (see ESO Press Photo eso0529) show it to be composed of gas ionised by the quasar radiation. This gas may have been captured through a collision with the star-forming galaxy. The star indicated on the figure is a nearby galactic star seen by chance in the field of view.